441: Ear Goobers
Transcript from 441: Ear Goobers with Mark Smith, Chris White, and Elecia White.
EW (00:00:06):
Welcome to Embedded. I am Elecia White, alongside Christopher White. Our guest this week is Mark Smith, and we are going to talk about halibut, satellites, amateur radio and ham.
CW (00:00:19):
Hi Mark. Thanks for joining the show and agreeing to tell me how to do everything I want to do.
MS (00:00:25):
<laugh> Thank you for having me on. It is great to chat with you guys.
EW (00:00:29):
Could you tell us about yourself, as if we met at a brunch after a nice visit at the electronic swap meet?
MS (00:00:40):
<laugh> I have had many of those brunches. Yeah, my name is Mark Smith. I often go by the name Smitty, or Smitty Halibut. Halibut has been my brand since I was a young kid and started a BBS back in the late eighties, called "The Halibut BBS," and it has just been unique, so I stick with it. I am a ham radio operator. I was in IT doing network engineering and system administration for 25, 30 years. Recently left that and have started my own company called "Halibut Electronics", making amateur radio and audiophile electronics.
EW (00:01:16):
Which we will be asking you more about. But first we have lightning round, where we ask you short questions and we want short answers. And because Nick, the exploding lemur, gave us a few extra questions, we are going to have to go through this pretty fast. Are you ready?
MS (00:01:32):
Am I ready for lightning round? Yes.
CW (00:01:34):
FT8 or JT65?
MS (00:01:38):
FT8.
EW (00:01:38):
Linear or circular polarization?
MS (00:01:43):
Circular.
CW (00:01:44):
Tube or transistor?
MS (00:01:46):
Depends on the context. I am going to go with tube because I like music.
EW (00:01:52):
CLI or GUI?
MS (00:01:55):
Again, depends on context, but most of the time, CLI.
CW (00:01:59):
How many clocks do you own?
MS (00:02:02):
Uh! Do I have the time to count them?
CW (00:02:08):
Order of magnitude.
MS (00:02:10):
More than ten in this room.
EW (00:02:13):
Defcon or Hamvention?
MS (00:02:16):
Ooh. I have been to Defcon way more often than I have been to Hamvention. I am going to go with Defcon. I think the parties are better.
CW (00:02:24):
Linear or circular polarization?
EW (00:02:27):
I said that one.
CW (00:02:28):
Linear or circular polarization? Okay.
MS (00:02:32):
Circular. Linear. Wait, no, I said circular last time. Linear this time.
CW (00:02:36):
<laugh> I am going to cancel that. Would you ever order a spicy chicken sandwich quote, "particularly hot"?
MS (00:02:43):
Only when Josh and Nick are around, and I would make sure that the chef heard it, so that we can hear a few minutes later, someone come from the back room, "<laugh> That can be arranged!"
CW (00:02:55):
All right <laugh>.
MS (00:02:57):
It is an inside story.
EW (00:02:58):
Do you have a piece of origami that you particularly like?
MS (00:03:04):
Yes! A very nice person gave it to me while I was driving north on Highway 1 through California, just a few months ago. Weeks? Weeks ago. However long ago it was. It is in a jar. I think it is an animal of some kind or a wave. I think it was a wave.
CW (00:03:20):
What is your favorite fictional robot?
MS (00:03:24):
Favorite fictional? Oh, chopper, obviously.
CW (00:03:27):
From Rebels.
MS (00:03:28):
From Star Wars Rebels.
EW (00:03:30):
Do you have a tip everyone should know?
MS (00:03:32):
Do I have a tip everyone should know? Move the decimal place one spot to the left and then double it.
CW (00:03:40):
Okay.
EW (00:03:42):
Decibels?
CW (00:03:43):
Decimal.
MS (00:03:44):
Decimal. How do you tip?
EW (00:03:45):
Oh.
MS (00:03:45):
I just tip 20%. Move the decimal place one place to the left and then double it. And that is your tip.
EW (00:03:50):
Oh, tip everyone should know.
MS (00:03:51):
Yeah.
EW (00:03:51):
Wow. All right.
CW (00:03:53):
That also works for estimates.
EW (00:03:55):
Yes.
MS (00:03:55):
Yeah. True.
CW (00:03:57):
<laugh> By tips-
MS (00:03:57):
20%.
EW (00:03:59):
Okay. While I am looking forward to talking to you about what you do professionally, we have tricked you into being on the show, because Chris's dad in Connecticut wants to talk to Christopher via code, without them spending a lot of money. Via ham radio code.
MS (00:04:20):
Mm-hmm <affirmative>. Morse code, I assume?
CW (00:04:22):
No, I am going to hand modulate FT8.
MS (00:04:24):
Okay. That sounds good.
EW (00:04:26):
I am thinking Morse code.
CW (00:04:28):
Wiggling the antenna.
EW (00:04:29):
Because Chris has been trying to learn Morse code, which he said it would be super easy. And I said-
CW (00:04:33):
No, I did not. When did I say that?
EW (00:04:36):
You said, "No, there is this method and once you learn one, you will never forget it."
CW (00:04:41):
Sure. Yeah. I have been. I have three letters.
EW (00:04:42):
Right.
CW (00:04:42):
<laugh> At 20 words per minute. Three 20. And they are not SOS I have got. Those are bonuses.
MS (00:04:49):
Would it be K, M and I cannot remember what the third letter is.
CW (00:04:51):
R.
MS (00:04:51):
What is it? R? K, M and R.
CW (00:04:53):
Yeah.
MS (00:04:53):
Someone is using the Koch method.
CW (00:04:56):
That is it? Yes.
EW (00:04:57):
Okay. So how-
MS (00:05:01):
K O C H, by the way, just so we are clear. Sorry, go on.
EW (00:05:03):
How can Christopher and his dad talk to each other over ham radio? What does that even mean?
CW (00:05:10):
Both of us are licensed.
MS (00:05:10):
That is a good start.
CW (00:05:10):
Both of us have done two meter stuff for years. Not between-
EW (00:05:15):
But not a lot. Neither one of you are deeply involved in the community.
CW (00:05:19):
Right. He did some HF stuff back in the eighties and nineties. He did code. I think he did some voice stuff, but I cannot remember. But he had a whole big rig and antenna and stuff at our old house, where we used to live in Southern CaliAnornia. But he does not have any of that stuff anymore. Or if he does, it has got to be reassembled. And I have never done any HF stuff, except for a little bit of WSPR stuff with a small kit.
(00:05:40):
So I do not really understand a lot of the words that fly around. I do not really understand antennas. I do not like them. I find everything about them confusing. I have the ARRL Antenna Guide and all of that, but I read that and it is like water down a Rain-Xed windshield.
EW (00:05:59):
Do you not have a physics degree?
CW (00:06:00):
Yeah, I did. But-
EW (00:06:02):
And you have more than a Technician license.
CW (00:06:04):
The physics of it is not helpful. <laugh>
MS (00:06:05):
<laugh>
EW (00:06:06):
Well, what kind of license do you have?
CW (00:06:08):
I have a General license.
EW (00:06:09):
Right. Okay.
MS (00:06:10):
Okay. Well, that is good because you need that to do HF. Does your dad also have a General or Extra?
CW (00:06:14):
He has a grandfathered Technician from the eighties, which gives him a lot privileges.
MS (00:06:20):
Oh, Tech Plus. Okay. Yeah.
CW (00:06:22):
Tech with code or whatever it was.
MS (00:06:24):
Yeah, that is the Tech Plus. Okay. All right. So that limits his ability. But you are talking about Morse code so that that opens it back up again. Okay. Cool. Got it. So we have just touched on a whole lot of stuff!
CW (00:06:36):
<laugh>
EW (00:06:36):
<laugh>
MS (00:06:37):
That I do not know whether you want me to explain what it means, because- Are you assuming that your listeners to the show understand what the heck we just said in the last minute, or?
CW (00:06:48):
Well, the truth about this show is, the listeners do not have a say in anything.
MS (00:06:51):
Okay.
EW (00:06:52):
You only have to amuse us. We do not worry too much about the listeners.
MS (00:06:56):
Very good, then. So you are not going to be- Okay. Well, actually that is not true. I was going to say, you are not going to be talking from California to Connecticut on two meters.
CW (00:07:06):
No, <laugh> well, not without a lot of repeaters.
MS (00:07:08):
Well, repeaters or the internet. There is a lot of internet linking of repeaters and hotspots and whatnot these days.
CW (00:07:16):
Yeah. That is fake.
EW (00:07:18):
Could you not just send email?
MS (00:07:19):
You can, yes.
CW (00:07:20):
I could just call them on the phone too. No, the goal is the project. The goal is to both be working on something together, and have this thing, you know.
MS (00:07:29):
So we are going to ignore the two meter options, the VHF, UHF options, and we are going to talk about direct communications without infrastructure other than the ionosphere. Between California and Connecticut.
CW (00:07:41):
Yes.
MS (00:07:41):
Okay. So in that regard, you are talking about HF. HF meaning high frequency, which is weirdly named because it is actually some of the lower frequencies we deal with. High frequency versus very high frequency VHF, or ultra high frequency, which is UHF. So HF is actually-
EW (00:08:02):
I saw that movie.
MS (00:08:03):
The UHF? Yeah, it was great. Fun fact. He went to the same college I did. He went to Cal Poly, San Luis Obispo.
CW (00:08:10):
Yeah.
MS (00:08:10):
He got his architecture degree there.
EW (00:08:13):
Why are there so many hams at SLO?
MS (00:08:16):
From Cal Poly?
EW (00:08:16):
Yeah.
MS (00:08:18):
Because Cal Poly has W6BHZ, one of the best college clubs in the world, in my opinion, not so humble opinion. I was a member of BHZ from 93 to 99. I know lots of people that were members before that, that have gone on to do great things. And many that have come after that, that have gone on to do great things. It has been an active club.
(00:08:43):
I think it is one of the oldest continuously running amateur radio clubs in the country. I think it was founded in 1949, 48, 49, somewhere around there, right after World War II. Right after hams got our permissions back after the end of World War II, the Cal Poly Amateur Radio Club was formed. It has got a long history and it is a great club. In fact, I just presented there this past Thursday.
CW (00:09:11):
I was a member of the ham radio club at Mudd.
EW (00:09:13):
<laugh>
CW (00:09:13):
Which consisted of-
EW (00:09:15):
You and Ross?
CW (00:09:15):
Which consisted of me, a guy named Andrew Ross, who was a friend of mine, and the staff advisor person who, I do not remember his name.
MS (00:09:25):
Who was legally required to be there?
CW (00:09:26):
Yeah. So there was-
EW (00:09:27):
Who was the staff advisor?
CW (00:09:28):
He was a guy who worked in the regular IT department, not the computer science department.
MS (00:09:35):
The poor schmuck that you looked up on QRZ, found out he had a call sign and said, "Hey, you work here."
CW (00:09:39):
Yeah. And I did not have a license at that point, and then did not get one while I was in the club. So that is how good the club was.
MS (00:09:46):
<laugh> It was a drinking club with a radio problem?
CW (00:09:49):
No, we wandered around the roof of the library some, looking at a antennas and things.
MS (00:09:53):
Oh, yeah, fair enough. I have done a fair bit of walking around on roofs.
CW (00:09:57):
Anyway, we are very off topic <laugh>.
MS (00:10:01):
Yeah. So, you are going to be talking about HF. HF means somewhere between 3 and 30MHz, is the frequency range that is defined by the words HF. HF frequencies are the kind that can go up from your antenna. They hit the edge of the atmosphere in an area called the "ionosphere," so-called because the sun's rays come in and ionize all of the atoms up there, and make it electrically reactive. It actually refracts that radio wave back down into the earth again. And in this way, you can do what is called "skip." So your radio waves kind of go out horizontally, the earth goes out from underneath it, it goes out, it hits the ionosphere, and then comes back down to the earth somewhere thousands of miles away. This is one of the primary modes of propagation in the HF bands.
EW (00:10:58):
And you said somewhere and that is important, because you can predict where, but not entirely.
MS (00:11:05):
Correct. The ionosphere changes all the time. The ionosphere changes based on the time of day, because it is being ionized by the sun, and the sun is not constant in our sky. Even then, there are other things that will affect the ionization in the upper atmosphere, like solar storms, right? If we have got a big solar storm that is coming, it will change it. I do not know whether it makes it bigger or smaller or moves it or whatever it does, but it changes, and it is moving all over the place.
(00:11:38):
The problem with HF communication is that it is not always predictable. You cannot say, "I will always have a path from X to Y." But you will almost certainly have a path to somewhere. So if you are trying to talk to a very specific person, you are going to have to keep an eye on when the path is open to that particular location. But if you are just trying to get on the air and talk to somebody, there will be somebody.
CW (00:12:10):
Yes. Okay. You mentioned the sun. What is that exactly?
EW (00:12:12):
<laugh>
MS (00:12:13):
The sun is this- They keep saying that fusion is about 20 years away. That is totally lies because nuclear fusion has been going on since almost the beginning of time.
CW (00:12:25):
I do not believe it.
MS (00:12:25):
We have had nuclear fusion in our planet for about the last four and a half billion years, if I remember correctly.
CW (00:12:31):
I do not believe it. I have never seen it. I do not believe it.
MS (00:12:35):
No? You must have very pasty skin.
CW (00:12:37):
<laugh>
EW (00:12:38):
The weather has been particularly bad here for a few weeks.
MS (00:12:41):
Well, yeah, that is true.
EW (00:12:42):
For you too, I think.
MS (00:12:43):
Yeah. Not as bad as you guys. We are not on a south facing hill. It was raining pretty hard this morning, but it looks like it has dried- Stopped raining. It has not dried up, but it has at least stop raining right now.
EW (00:12:54):
So time of day affects the ability to refract through the ionosphere.
MS (00:13:01):
Correct.
EW (00:13:01):
Does weather?
MS (00:13:05):
Not generally. Some aspects of weather can affect your noise floor. Like if there is a lot of lightning going on, that creates a lot of electromagnetic interference, and that will sound like a crash. They call it "lightning crashes" in your receiver. It creates noise and it makes it harder to hear weak signals. And it does not even have to be lightning nearby. Lightning crash noise will travel thousands of miles. That is called "ground wave propagation," where it actually travels along the surface of the earth. It does not necessarily bounce off the ionosphere.
(00:13:44):
But that is about the only thing I can think of. Like rainy versus sunny, I do not think is going to affect, because that is all low altitude stuff. The ionosphere is tens of thousands of feet up, hundreds of thousands of feet up.
EW (00:13:57):
And you were talking about UHF and VHF. The higher frequencies than HF. Am I looking at like a 40 meter antenna to put somewhere, or?
CW (00:14:12):
We are going to get an antenna.
EW (00:14:13):
You mentioned two meter. Two meter is VF?
CW (00:14:17):
VHF.
EW (00:14:17):
VHF.
MS (00:14:18):
VHF. Yeah. So the meters that we are talking about here are the wavelengths. So the actual length of the electromagnetic wave as it travels through the medium. Air in our case.
EW (00:14:29):
Which is inversely proportional to?
CW (00:14:33):
The frequency.
MS (00:14:34):
Frequency, correct.
EW (00:14:35):
The frequency in Hertz, and waves in meters.
CW (00:14:38):
And the speed of light. You got to throw a speed of light in there.
MS (00:14:40):
Yep. There is a C in there somewhere.
EW (00:14:42):
Oh, right. I forget about that. This is like a three. And then you ignore the rest of the-
CW (00:14:46):
It is a constant. You just normalize everything. Yeah.
MS (00:14:47):
Yeah. Three and a hundred million, and that is all you have to remember. Yeah. But basically as the frequency goes up, your wavelength goes down. As your wavelength goes up, your frequency goes down. By the same proportion. 100MHz is about three meters long. 200MHz, twice the frequency, is about one and a half meters long, half the wavelength. So it goes up and down by the same amount. Okay. You were asking about VHF and UHF, and do you need a 40 meter antenna and all that stuff? So the "40 meters" on a 40 meter antenna, is not how big the antenna is. It is-
EW (00:15:31):
It can be. <laugh> I have seen these guys.
MS (00:15:34):
<laugh> So a 40 meter long antenna would be used to receive the 80 meter band, because typically you are putting up what is called a "half wave dipole." That is the basic element of any antenna, and a half wave dipole is as the name makes it sound a half wavelength long. So if you are trying to receive or transmit on the 80 meter band, your antenna is roughly 40 meters long. Similarly, if you have got a two meter radio- Actually, once you get into VHF and UHF, you are not typically doing dipoles. You do what is called a "ground plane," which is only a quarter of a wave length long. So, at two meters, your antenna is about 50 centimeters long, which ends up being about 19 inches.
EW (00:16:25):
Okay. So we were talking about the frequency Christopher needs, HF. You gave a range for that, but I have already forgotten it.
MS (00:16:34):
Yes. By definition, the term HF refers to any frequency between 3 and 30 MHz. As amateur radio operators, we are only allowed certain little slivers of that band between 3 and 30MHz. Okay, let us do this. HF is 3 to 30MHz, VHF is 30 to 300, UHF is 300 to 3000, so on and so forth. Right? So each of those very wide spectrums, swaths of spectrum is a decade wide. Times 10 in frequency, or divide 10 in wavelength, right?
(00:17:16):
So HF is 3 to 30MHz wide. We hams only get little slivers inside there. Even then, depending on your class of license- So we mentioned earlier there, Christopher has a General Class license, and that your dad has a Technician Plus license or a grandfathered Technician license from the eighties when he actually had to pass a Morse code test to get his license. Those classes of license also dictate on what frequencies you are allowed to transmit. These rules only apply to transmit, you are allowed to receive-
CW (00:18:00):
Sure. How are they going to stop you <laugh>.
MS (00:18:02):
Well, no, do not take that for granted because a lot of countries, that is not true.
CW (00:18:06):
Oh, yeah. True.
MS (00:18:07):
Like if you go to the UK, they do have restrictions on receiving signals.
CW (00:18:14):
Right. TV.
MS (00:18:16):
Yeah. TV licenses and stuff like that. The amateur bands, anyone is allowed to receive. The rules are explicit about that, but you are not allowed to receive certain- It is a allow list, not a deny list. Right. So these are the frequencies you are allowed to receive, everything else you are not allowed to receive, which is completely foreign to me, because here in the US it is a deny list. You are allowed to receive everything, except for these few swaths that have exclusions, for cellular, and I think land cordless phones. I think that exception may have been removed, but you used to not be allowed to receive cordless phones, that kind of stuff.
(00:19:02):
Anyway, your license class dictates what frequencies you are allowed. As a General, you have privileges in every ham band in the HF section. You do not have all of the ham bands in the HF section, as in you have at least a little bit in every single band, but you do not have the entire band.
CW (00:19:27):
Sure.
MS (00:19:28):
Your dad as a Tech Plus has much more restricted permissions. He is not allowed to do voice on any band except 10 meters, which is roughly 29 MHz, 28 to 29 MHz. So there is only a small section of voice that he is allowed to do, up near the very top of the HF band. And the 10 meter band is not always open. We are actually at a pretty good time right now of the sunspot cycle for 10 meters. 10 meters is pretty open right now, and it will be for the next five years or so. But, the other half of the sunspot cycle, 10 meters is closed. It never opens up. You can do local communications and that is it. At no point does it ever skip off the ionosphere.
EW (00:20:19):
Okay. So we are saying they should use 10 meters-
MS (00:20:22):
No.
EW (00:20:22):
Because they both can. And they want to do it in the next five years.
CW (00:20:25):
He may upgrade his license, so let us not get too worried about the Tech-
EW (00:20:29):
I still want to go back to how much of an antenna are you going to need.
CW (00:20:32):
<laugh>
EW (00:20:32):
And how much your mother and I need to discuss this.
CW (00:20:36):
All right. <laugh>
MS (00:20:38):
<laugh> Let us assume he has not upgraded yet. The best band for him would probably be the 40 meter band, which ends up with an antenna about 65 feet long, which is what Elecia is really trying to get to.
CW (00:20:53):
Okay.
EW (00:20:53):
Yeah.
MS (00:20:54):
Let me just boil it all down. You have a 65 foot section of wire with a feed point in the middle of it. So you got to run the coax up to the middle of the 65 foot section of wire.
CW (00:21:03):
Yeah. Okay, Mark, but tell me about the end fed half wave antenna.
MS (00:21:09):
The end fed half. Okay. So I just said you had to run the feed line up to the middle of that. That is for a half wave dipole. Di pole, meaning two poles. So I have got a quarter wave on one side and a quarter wave on the other. That is the basic element of a antenna. That is what resonates, right?
(00:21:27):
Think of a guitar string. You are a musician. Think of a guitar string. A guitar string, when you pluck it, it resonates half of a full wavelength, right? The entire thing- We are not talking about harmonics. Do not worry about 12th fret harmonics, because that is a whole different thing. But if you just pluck the string, the whole thing moves up and down and it looks like half of a sine wave, right? That is exactly what you are doing electrically with the wire that is up in the sky.
EW (00:21:54):
That is 65 feet long.
(00:21:55):
65 foot long wire, because that means-
CW (00:21:58):
She is getting hung up on this. It does not have to be straight into the sky. <laugh>
EW (00:22:02):
<laugh>
MS (00:22:03):
It not tall. This is horizontal.
CW (00:22:06):
Yeah. I can just string it down the backyard.
MS (00:22:09):
Now the higher you can get it, the better. But if you can only get it ten feet high, then you can get it ten feet high, and you can make it work. If you could get it higher than that, it would work a little bit better. But it does not mean that it will not work when it is relatively low to the ground.
CW (00:22:25):
So it has to be a half wave length. You cannot get by with- I have read about end fed half waves, and I have seen people do things, "Oh, I have random wire length and I just tune it," or, "I have a quarter wave and it works okay." What does that actually mean? Does it mean like the efficiency is way down and it is not going to reach as far, or I am going to knock out my neighbor's microwave?
MS (00:22:49):
Well, you may do that anyway, but that is a different issue. We will talk about that later if you want. The basic element of an antenna as a half wave, because it resonates, right. Now, there are things that you can do to make that resonate differently. One of the things you can do is you can change the feed point, right? Like the feed point is basically where your guitar pick hits the string. Where are you exciting it? And you know how the tone of a string is different when you pluck it in the center versus when you pluck it close to the bridge? That is roughly speaking, the analogy is straining here. That is roughly the impedance of the antenna.
CW (00:23:26):
Sure. Okay. All right.
MS (00:23:27):
All right. So when you feed your half wave antenna in the center, the impedance is closest to 50 ohms. It ends up being closer to like 72 ohms. And all of the coax that we use is either 50 or 75 ohms. So it is really good to feed it in the center, because that is the natural way all of this wants to work.
CW (00:23:46):
I see.
MS (00:23:46):
You can then move that feed point from the center, and do, let us say, roughly one third on one side and two thirds on the other side of your total half wave wavelength. That is what is called an off-center fed dipole. It works roughly the same, but the impedance changes. I think in that case, the impedance goes up to about 200 ohms. I might be misremembering that, so do not quote me on it. But it means that you have to put a little device at the feed point that transforms the impedance from your 50 ohm coax, to the roughly 200 ohms of the feed point.
(00:24:23):
But by doing that, it now can resonate on different frequencies, kind of like a harmonic on a guitar string. For non-musicians, if you pluck a string, the whole thing moves up and down. If you put your finger halfway along the string, which is the 12th fret, and then you pluck the string, it makes a node right at the middle of that string. And so now each half of the string is resonating opposite of each other, and it makes a tone that is one octave higher, because it is now twice the frequency, the wavelengths are half as long.
(00:24:58):
You can kind of start doing the same thing with the feed point of your antenna. Then if you move the feed point all the way to the end, the impedance gets super high. You can kind of like fake it with a lot of things. You end up needing an antenna tuner, it is a matching network, and you can do some magical things there.
(00:25:24):
The problem with this is that it ends up having a very difficult to predict radiation pattern. If you stick it up in the air, you will radiate, there will be somebody somewhere that can hear you. It is very difficult to say, "I know exactly where this is going to go when I put it up."
CW (00:25:42):
Oh! All right.
MS (00:25:43):
You can put it up and say, "Hey, who is hearing me?" And then figure it out after the fact. But it is difficult to design a system and say, "I know I want to talk to this person, that they are here, and therefore I orient the antenna this way." It gets much more complicated. You have like weird lobes and nulls in your radiation pattern.
EW (00:26:05):
Going back to the guitar example, that would be like plucking the string at one end or the other and then using something else to actually make it...
CW (00:26:16):
I am not sure the analogy holds up <laugh> in that extreme.
EW (00:26:20):
At that point you are just hearing a click, maybe.
MS (00:26:23):
So if you pluck the string right next to the bridge, you end up with a lot of higher frequency harmonics in the resonance of the string. That kind of happens with an antenna too. It allows you to radiate- Let us say we have got that 65 foot piece of wire, right? So it is a half wave at 40 meters. You can also get it to resonate at 20 meters. You can also get it to resonate at 15 meters. You can also get it to resonate at 10 meters. The big draw to these kinds of antennas is that they are multi-band.
CW (00:26:59):
And when you go down a band- So if I have the 65 foot, if I go down a band, does it have the same unpredictability when I leave the 40 meter band, as fixing up an end fed half wave? Or is it because it is a multiple, it is all going to be predictable?
MS (00:27:16):
If you are using the fundamental, I think it will always pretty much radiate like a half wave. Yeah. To be clear on that, the radiation pattern comes off the broad side of the antenna. When we are talking about these kinds of antennas, there are other kinds of antennas that are called "traveling-wave antennas," like a Beverage, which we will not get into here, where the radiation pattern is along the length of the wire. So you would point the tip of the wire at the station you want to receive, but that is not what we are talking about here. We are talking about the half wave resonance, and those all radiate on the broad side, and then they have nulls out the tips of the wire.
EW (00:27:54):
So we need it to be horizontal. Do we need the ends to point east-west, north-south? Does it matter? Once it is horizontal, does it matter at all which way the orientation is?
MS (00:28:14):
So, it does not need to be horizontal. You can do vertical antennas, but you were making it sound like you did not want a 65 foot tall piece of wire in your yard.
CW (00:28:24):
No, I am not putting a pole up.
MS (00:28:25):
Yeah. And actually, that one would only be a quarter wave if you did a vertical. So it would only be 32 feet long.
CW (00:28:32):
That is still too high.
MS (00:28:33):
That is still too high. Okay. So we are talking about horizontal antennas here. And if we are talking about a horizontal antenna, then ideally, and again, this is where you can predict how it is going to work. It would be straight, it would be high in the air, and you would point the broad side of the wire in the direction you want your signals to go. That is the ideal situation.
(00:28:55):
Having said that, stick the wire up anywhere you can get it up, it will work. If it is not perfectly straight, if it bends halfway through, or if you have got like weird curves, or you have to turn the corner around the fence line because your yard is not quite 65 feet long. It is only 50 feet long, so you have got 15 feet that has kind of made a right turn and gone on. That is fine. Put it up, it will work.
(00:29:24):
Again. You are going to have these weird radiation patterns that you will not necessarily be able to predict, but it is going to work, and you will be able to hear somebody and somebody will be able to hear you. And when the conditions are right, that might even be your dad in Connecticut.
CW (00:29:39):
Okay. So dipole sounds like the way to go. Even though I was reading all about end fed half wave. I do not know why I was so excited about those. Probably because I like the-
EW (00:29:46):
The variability? It is kind of cool.
CW (00:29:48):
No, it seemed cool that you could just stick up a wire and have lots of magic happen. But maybe I should ignore the magic.
MS (00:29:56):
End feds are great when you want the antenna to come in- Like if your shack is at one end of the antenna, right?
CW (00:30:06):
Right.
MS (00:30:08):
Your shack is on one side of the house, and then your antenna just leaves straight from the shack and goes down or whatever. Because then your feed point is at the end, and that is just super convenient to put up. The other advantage to an end fed is that they are multi-band. If you do a resonant end fed, where the length is a very specific length, then you can get all harmonics of the base frequency, the fundamental frequency. Looking on all the ham bands, you will notice that they are harmonics of each other. Three and a half megahertz, 7MHz, 14MHz, 21MHz, 24MHz, 28MHz, stuff like that. They are all multiples of each other, which is nice. It means that our harmonics from bad transmitters only affect ourselves.
EW (00:31:03):
Yes.
CW (00:31:04):
It is very clever. I did not know that. Okay.
MS (00:31:06):
Yeah. But it also means that if we have an antenna that will resonate on harmonics, we can use that antenna on multiples of our own bands.
CW (00:31:15):
Okay.
EW (00:31:18):
Okay. So antenna aside. Assume we get the right antenna, of the right length, whether it goes sort of downhill from our house, or maybe a drone puts it in a tree. You have an antenna.
MS (00:31:32):
Yeah.
EW (00:31:33):
What is the minimum viable HF setup?
MS (00:31:36):
Okay, so you got the antenna, you are going to need to get coax down to wherever the radio is. I recommend putting what is sometimes called a "balun," also known as a "common mode current choke" at the feed point of the antenna. If you have a perfect antenna that is perfectly straight in free space with nothing else around it, you do not need a balun.
EW (00:31:56):
That sounds impossible.
CW (00:31:58):
I live in a forest.
MS (00:31:59):
No. Yeah. Nobody has that perfect environment. So stick a balun or a common mode current choke at the feed point of the antenna, it will solve all kinds of problems.
CW (00:32:07):
Balin was the dwarf that went to Moria, is that right?
MS (00:32:12):
It was one of the 12. Yeah. <laugh> I think he was the one with the ear horn, who could not hear very well.
CW (00:32:20):
What is a balun?
MS (00:32:21):
A balun stands for balanced-
EW (00:32:23):
He said. It was a choke current-
CW (00:32:26):
That does not help me!
MS (00:32:29):
<laugh> The term "balun," refers to a balanced to unbalanced converter.
CW (00:32:34):
All right.
EW (00:32:37):
Balanced to unbalanced converter. Like an analog to digital converter takes analog and makes it digital. This takes balanced and makes it unbalanced?
CW (00:32:48):
Or vice versa.
MS (00:32:50):
It is bidirectional and in this case, it is going the other direction. Well, it goes the other direction on transmit. Yeah. Anyway. Your coax is unbalanced, right? Because I have got one driven electrical lead, and then just a ground reference around it. Right? So that is an unbalanced signal. But your dipole is balanced. I have got two quarter waves sticking out on either side, and they are operating opposite of each other.
CW (00:33:15):
Right. And so when the coax attaches to that, it is going to attach to- I mean, if you did not have a balun, you would be attaching the core to one side of the dipole and the ground to the other?
MS (00:33:27):
Correct.
CW (00:33:28):
And that is not- Okay.
MS (00:33:30):
It actually ends up working out okay. Because our currents, that are relevant here, not voltages. But the problem comes when your antenna is not perfectly symmetric. Now you get unbalanced currents in your antenna.
CW (00:33:43):
Okay! Okay.
MS (00:33:43):
And those unbalanced currents actually come back as common mode on the outside of your coax, and reek merry havoc with things.
CW (00:33:52):
Okay. And so a balun does something magical with, I assume, loops of wire and transformers that I do not understand to fix all that.
MS (00:34:00):
Yeah. You know what a common mode choke is?
CW (00:34:04):
Let us pretend that I do not.
MS (00:34:06):
Let us pretend that you do not. Okay. For the benefit of the audience. Absolutely. So, balanced currents are currents that are matched, right? I have this one amp going that direction and another amp coming back that direction. That is a balanced current that is known as "differential mode currents." They have the same amount of current going in opposite directions.
(00:34:26):
If you run that through a inductor, then the magnetic fields from those balanced currents will cancel each other out, and it basically makes the inductor completely transparent. Right? And so differential mode's currents will pass right through an inductor, assuming you wind it correctly, which is what we are doing here. But a imbalance in those currents, whatever is different between the two different wires going through this inductor, does create a net magnetic field. And that inductor then acts like a, let us see here, low pass filter, because it will pass DC but it blocks AC. So yes, it acts like a low pass filter.
(00:35:14):
So if you make this inductor big enough, then it just basically blocks all radio frequencies, but only the common mode of those those radio frequencies. So it forces the currents going through that device to be differential mode. It looks like a very high impedance to common mode, and a very low impedance to differential modes. And when you have that high impedance to common modes, then it basically says, "Nuh-ah, I know you are not symmetric out on the antenna, but you cannot reflect that other stuff back down the antenna. Or, back down the feed line, excuse me.
CW (00:35:52):
All right. Cool. I think I kind of understand that.
MS (00:35:55):
So in this case, it kind of acts like a protection device.
CW (00:36:00):
Okay. So we have got an antenna. We have got a balun.
MS (00:36:03):
You got a balun, you got the feed line that brings it down to your shack. Now what radio do you connect it to? There are a bajillion and a half answers to this question. You are looking for what is the simplest that we can do.
EW (00:36:17):
But also safe, because there have been some radios lately that are coming out of other countries that- This is more the UHF.
MS (00:36:30):
Oh VHF and UHF. Yeah, the Baofengs and the- Yeah.
CW (00:36:32):
I have one of those. <laugh>
EW (00:36:33):
And they do not-
MS (00:36:35):
They are not great.
EW (00:36:36):
They litter on the other frequencies.
MS (00:36:39):
Yeah. They are not great.
EW (00:36:41):
Okay. So we want one that is not in the "not great" category.
MS (00:36:46):
Sounds good. So...
EW (00:36:50):
Do not want the FCC showing up here, waving their guns around.
CW (00:36:53):
Nah, it is other hams in pickup trucks, usually.
MS (00:36:55):
Yeah. Okay. What is your budget? Are we talking hundred dollars, thousand dollars, or 10,000 dollar?
CW (00:37:06):
Let us shoot for $500 or less.
MS (00:37:09):
$500 or less. Okay. So we are looking at either a used HF radio, and if you get anything from- I am just going to make a broad generalization. Anything from Kenwood, Yaesu, or Icom, is going to be fine. You are not going to get the FCC knocking down your door. Assuming the thing is functioning, and if it comes from one of the big manufacturers, it is going to be fine from a "FCC knocking on your door" standpoint. So a used radio is a very good option, because, shock and horror, Morse code has not changed in the last hundred years, right? Since-
CW (00:37:50):
And yet I still cannot learn it.
MS (00:37:52):
<laugh> You are a musician man. Come on! Once we learned how to put out a continuous wave of signal instead of a spark gap, which I think we figured out how to do in the twenties, CW transmitters have not changed. By the way, that is what CW means. The term nowadays CW and Morse code are roughly equivalent, they are roughly synonymous.
(00:38:17):
Radio will often say, "You put it into the CW mode." What the heck does CW mean? CW means continuous wave. Okay, great. I thought all transmissions were continuous wave. I am going to ignore single sideband for the time being. CW is a term that differentiated it from spark gap, which was not a continuous wave. Spark gap is noise that you would filter down to try and narrow the amount of bandwidth that it took up.
(00:38:46):
Anyway, any radio from the last a hundred years that can do CW will work just fine today, to be able to talk CW to anybody else. So any used radio from the last 20 or 30 years, is basically anything that is solid state. Unless you want to get into doing tube radios?
CW (00:39:08):
I do not.
MS (00:39:08):
Okay. Then stick with solid state. And anything from the last 20 or 30 years is going to be a fine radio. You will not have any problems with that. If you want something new, there are lots of different options. Do you want a kit? Something that you assemble and learn a little bit about the radio as you go, and say, "Hey, I built this, this is pretty cool."
CW (00:39:32):
So I can do a kit. I built the QRP Labs, what was it called? Something, something, three.
MS (00:39:40):
Oh, the Ultimate3?
CW (00:39:40):
Yeah. Ultimate3. And I built a bunch of filter modules for that, and played around with that, so I did that. That was okay. That was not a big deal.
MS (00:39:47):
Okay. So the Ultimate3 is the WSPR beacon. I have one of those as well, and those are really cool. WSPR stands for "Weak Signal Propagation Reporting." It is a digital mode. We are not going to get into it here. We want to stick to CW-
EW (00:39:59):
We actually have a show about it.
MS (00:40:01):
Oh, you do?
EW (00:40:01):
Go listen to that show instead.
MS (00:40:03):
You want to do CW, so- Actually from QRP Labs, the kit I was going to recommend is called the QCX. The QCX is a CW transceiver.
CW (00:40:15):
Oh, okay.
MS (00:40:16):
Leave their mono band. So you pick a band.
CW (00:40:18):
Ah.
MS (00:40:22):
But they are less than a hundred dollars.
CW (00:40:22):
Oh, so I can just stack them.
MS (00:40:25):
Yeah, exactly. They are less than a hundred bucks and you make them for-
CW (00:40:30):
55 bucks!
MS (00:40:31):
Yeah.
EW (00:40:31):
They are like candy. You can get ten of those.
CW (00:40:33):
Oh, okay.
MS (00:40:34):
It is a wonderful kit.
CW (00:40:38):
But I see that this is five watts. That was another question I had for you, surrounding the HF rig thing, is what power? I have no notion of what power- So I see people with a hundred watt radios. I am like, "Okay, is that how much you need to get significant distances, or is five watts fine?"
MS (00:40:55):
So five watts is what is called QRP. The Q-codes are from the old Morse code days, like telegraph days. Q-codes are short little three letter codes that have meanings. They are somewhat arbitrary. You have to memorize them or look them up. QRP means "lower your power output," or "low power output."
CW (00:41:19):
<laugh> Shut up!
MS (00:41:21):
<laugh>. Basically what it means is, "Your signal is incredibly strong here. You can transmit on less power if you want to."
EW (00:41:26):
And QCX is "Hello? Hello? Is anybody there?" Is that right?
MS (00:41:30):
CQ.
CW (00:41:31):
CQ.
EW (00:41:32):
CQ!
MS (00:41:33):
Yes. So CQ, you can think of it like "seek you," is the way that I remember that one. The advantage to CQ is that it makes a very recognizable sound in Morse code, da di da dit, da da di dah. You can pick that out of a pile of noise and blips and bleeps. If I hear, "da di da dit, da da di dah," I know exactly what it is and what it means.
CW (00:42:00):
Even I know that one.
MS (00:42:00):
Yeah.
EW (00:42:03):
I still do not, and he said it twice. So, he is not going to get through to me.
MS (00:42:07):
<laugh> QRP, so it is a low power transceiver. There is a huge community around QRP transceivers, because it is amazing what you can do with so little power. CW or Morse code puts all that power behind a very narrow range of frequencies. It is one tone, right? It is called your "power spectral density." The wider your signal is, the more frequency range it uses, for the same amount of power. You end up getting less amplitude out of it, right?
(00:42:46):
So you can think of power as kind of the integral of the shape of your signal, right? The area underneath the graph. If you have just got a very narrow spike, then it makes a very strong signal. As opposed to single sideband, which is a human voice, which is about 2.7KHz wide. As opposed to Morse code, which is typically 10Hz wide, right? 10 or 20Hz wide. You have to spread your power out over a larger range of frequencies, so it ends up having a lower overall amplitude, and lower all overall effectiveness for the same amount of power. So five watts on CW is actually way more powerful than it sounds.
CW (00:43:32):
Okay.
MS (00:43:32):
If you had a hundred watt transceiver, you are going to be able to get through a lot of situations that a QRP radio just cannot. But part of the fun with QRP is I have got this little tiny battery powered thing I can fit in my pocket, and a spool of wire, 30 gauge wire, that is super tiny, that I can walk to a park, throw up in a tree, and start pounding out contacts with Morse code. With this little tiny kit that I built, that runs off of three AAs, or whatever battery you choose to put in there.
(00:44:11):
There is a lot of pride that goes along with what can I do, with as little resources as I have. If you want to make sure you can talk to the person, and you do not want to have to deal with current conditions, then get a hundred watt transceiver.
CW (00:44:24):
Well I just noticed they have a 50W amp you can buy for it.
MS (00:44:27):
They do, yeah.
CW (00:44:27):
So that would probably fix that, if that was a problem.
EW (00:44:30):
Okay. So is 50 watts enough for him to talk to Connecticut?
MS (00:44:35):
Almost certainly. Almost certainly.
EW (00:44:37):
And five watts would be, you would kind of have to try and wake up at 3:00 AM sorts of things.
MS (00:44:43):
<laugh>
CW (00:44:44):
Probably not 3:00 AM.
MS (00:44:46):
Yeah, well on 40 meters- So the advantage to 40 meters is that it is open most of the day. Pretty much all the time, 40 meters is open. There are times where it is noisier than others. And there are times where there are other bands that are going to be better than 40 meters, but it is pretty much always open to somewhere.
(00:45:06):
The higher the frequency, the more susceptible to ionospheric change you are. There is what is called the "maximum usable frequency," and it kind of moves up and down. Above that frequency, and the band is just closed. It does not refract anywhere. Below that frequency, your signal is bouncing around.
EW (00:45:27):
Which is how you can get to incredibly strange places, because it goes- It not only would jump from California to Connecticut, it may take a path that is it hits Kansas, and then back up and then down to Connecticut and then back up and off to France or wherever.
MS (00:45:43):
Yeah. That is called "multi-skip." Yeah, multi-skip is definitely a thing. Over here on the West Coast, going across the Pacific is incredibly common. You will hear stations from New Zealand and Australia and Japan and China, and all of Eastern Asia. It is wide open to us, because there is nothing between here and there except very reflective water and very refractive ionosphere.
CW (00:46:10):
All right, I like this idea. Oh, and has a GPS interface like the other thing. And can do WSPR as well. All right.
MS (00:46:16):
It can do WSPR, yeah. It will not do voice. It is-
CW (00:46:20):
I do not like talking to people, anyway. Present company excepted.
MS (00:46:23):
<laugh> Says people who have their own podcast.
CW (00:46:28):
I am talking at people.
MS (00:46:30):
Yeah, that is true.
EW (00:46:32):
<laugh>
MS (00:46:34):
Makes perfect sense.
CW (00:46:36):
<laugh> Okay, so I have got this, and the antenna. I assume I have got a key somewhere. I will figure that out. Do I need an SWR meter?
MS (00:46:47):
So an SWR meter is something that you need when you set up your antenna. And if you ever think your antenna is broken. You do not need the SWR meter in-line every time you operate.
CW (00:47:01):
And this is a thing that you put in between your antenna and the transceiver, and it tells you if there is lots of bad juju, mojo, bad stuff coming back down the antenna into your transceiver.
EW (00:47:12):
But is not that why you have the balun thing?
MS (00:47:16):
The balun, yeah. So the balun will help protect against this. The SWR meter is verifying that everything is doing the right thing. The balun at the antenna will not protect you against a failure in your coax. If your coax is broken, the balun at the antenna is not going to do anything to protect you against that.
CW (00:47:34):
Okay.
MS (00:47:34):
That will send all your energy right back at your transmitter. And bad things happen. So the SWR meter, standing wave ratio, it measures the amount of power going out, versus the amount of power coming back. In an ideal situation, zero comes back and it all gets radiated. You will never be perfectly ideal. The ideal situation is called a "one-to-one ratio" where- Do not ask me to explain what the ratio is, because it is weird.
(00:48:03):
Anyway, one-to-one means that you have zero energy coming back from the antenna. Typically, two-to-one is considered totally safe and acceptable. You can kind of get away up to three-to-one most of the time, but anything above three-to-one, and you want to stop transmitting and figure out what is going on.
CW (00:48:23):
Okay.
EW (00:48:24):
Okay. Have I lost you, and I should ask him other things?
CW (00:48:26):
Well, I am looking at the order form now. There are a lot of options here I got to think about. Like, do I need this dummy load thing? And this TCXO, what the hell is that?
MS (00:48:35):
You do not need a TCXO. Do you know what it- Temperature control oscillator.
CW (00:48:39):
Oh, yeah. Okay. I know what they are.
MS (00:48:40):
You do not care how stable your frequency is. For what you are doing, you do not need a TCXO.
CW (00:48:43):
Ah, okay.
EW (00:48:45):
It is not stable anyway. It does not matter. It might help you get to your dad. Who knows?
CW (00:48:48):
<laugh>
MS (00:48:52):
Dummy loads will help while you are building things, because it means you can transmit into a known good load, while you are testing your transmitter.
CW (00:49:01):
I cannot just put the wires into a bucket of sand?
MS (00:49:05):
Unless you know it is exactly a 50 ohm non-reactive bucket of sand. Probably not.
CW (00:49:11):
Alright.
MS (00:49:11):
Yeah.
EW (00:49:12):
How do you get the resistance of the beach?
CW (00:49:13):
<laugh>
MS (00:49:16):
There are ways of measuring the impedance of ground. It can be done.
EW (00:49:21):
Okay. While Christopher fills out that form, and-
MS (00:49:23):
And buys a new radio.
EW (00:49:23):
And {inaudible} gets additional information about the acronyms. I too have an amateur radio license.
MS (00:49:33):
Oh, nice.
EW (00:49:36):
I mean, the test was not that hard.
MS (00:49:37):
Nope. It is not.
EW (00:49:39):
And if you study for it, and then you go in and you take it right away, it is totally easy, because I memorize things well. But anyway, that does not help at all. I mean, I can pass the test. I probably could pass the General test, if I studied more for it, because it is just physics and math and I can do those things.
MS (00:49:58):
Yeah.
EW (00:49:58):
But this process of setting everything up, and figuring out how to put it together. I mean, I can say which bands I am allowed on. And I know how to translate frequency to meters, except for the speed of light. But there is so much more. And I am not super comfortable hanging out with the ham clubs, because-
MS (00:50:25):
Oh, boy.
EW (00:50:26):
I am, weirdly, as I get older, I am still younger than all of them put together. No, all of them.
CW (00:50:36):
<laugh>
MS (00:50:36):
Yep.
EW (00:50:36):
And there is a certain gender problem, and a certain homogeneity, to many ham clubs. And I can only take so much mansplaining in a year. And they usually, take it with that-
CW (00:50:52):
She gets to that in a month from me.
EW (00:50:54):
No, but the ham radio clubs, I get a year's worth in an hour.
CW (00:50:59):
I remember having- That happened to me when I took the exams sometimes. I was, "I am just here for the exam. Please stop talking to me."
EW (00:51:06):
Right. Yeah!
MS (00:51:08):
Yeah. Yes, you are absolutely correct. I am going to pull the typical cishet straight white dude answer and say, "Not all ham clubs." But many ham clubs, and certainly a lot of the vocal ones. It seems like a lot of the ones that are trying to do the outreach, are the ones who are trying- I do not know how to word this. They have not figured out how to do it correctly.
(00:51:43):
The communities and the ham radio larger community, that are looking at the demographics of the ham and saying, "Wow, we are getting old and we are dying off. We need to get more young people into the hobby. Why is that so hard these days?" Well, because before the nineties, ham radio was actually a practical hobby.
(00:52:10):
You could use it to talk to your friends across town or across the world. You could use it to meet people from the other side of the world, and talk about things that you had- You had a built-in common hobby, amateur radio, and it was a way of communicating for free, that was not otherwise available to us with super expensive long distance.
(00:52:34):
When your TV and radio stations were only the local broadcast. Maybe you were lucky to have your national television network. But you did not really get news from the rest of the world. And so radio was the way that people communicated long distances, with people other than people that were within walking or driving distance from them.
EW (00:52:57):
So the internet killed the amateur radio star?
CW (00:52:59):
<laugh>
MS (00:53:00):
The internet killed amateur radio as a practical hobby. Internet and free long distance. Both happened at the same time, right?
CW (00:53:13):
Well, I remember when we first had licenses. We used to talk when you were on the way home from Palo Alto. We would talk over two meter, and do the stuff we would normally have done on a cell phone.
EW (00:53:21):
Yeah.
MS (00:53:22):
On a cell phone. Exactly. And nowadays-
EW (00:53:24):
But there is also when I went to the emergency response team training in my community, the fact that I had a ham license was really exciting to them.
MS (00:53:35):
CERT training? Is that what you did?
EW (00:53:36):
Yeah. CERT.
MS (00:53:38):
Yeah, CERT. It was a community emergency response training, I think is what it stands for.
EW (00:53:41):
Yeah. Team, I think is what the T is for.
MS (00:53:43):
Team. Okay.
EW (00:53:45):
Does that matter anymore? I mean, does anybody use amateur radio for disaster situations anymore?
MS (00:53:53):
So the short answer is, "Yes, they do." I have very unpopular opinions about this, within the ham community. Go ahead and rev up your email programs now. mark@halibut.com. Just go ahead and hit Control N and start writing your response to me, telling me how wrong I am. Right now.
EW (00:54:16):
<laugh>
CW (00:54:17):
You could have left that out, and it would all come to us, and we would have filtered it for you.
MS (00:54:21):
No, I do not want to put you guys through this. I am personally of the opinion, that hams in emergency response situations are not as useful as we were even about two decades ago, a decade to two decades ago. We used to be incredibly useful for local situations, like earthquakes or floods or power outages or anything like that, where conventional communications went down. Telephone lines are incredibly reliable, until they are not. And when they are not reliable-
(00:55:03):
But the police and Red Cross and Fire- Police and fire, they have their own radio systems, but the Red Cross does not, and all of these radio systems do not necessarily intercommunicate with each other. But things like 9/11, things like Hurricane Katrina, these have given city and state, and even cell company groups a wake up call. And they said, "All right, we need better communications. We cannot suffer these kinds of problems anymore. This is getting more and more common. We need to actually invest the money in reliable communications."
(00:55:43):
And cellular companies are doing the same, right? It is now no longer the case that the cell companies' cell towers just fall over. Not physically fall over, but electrically fall over. They just stop working whenever there is a power outage, or where there is an earthquake, or whatever it is, right.
CW (00:56:00):
Yours may not..
MS (00:56:02):
<laugh> In San Luis Obispo, they do not. And the phone companies are very reliable now. These kinds of communications used to go out all the time. And they would call in hams to provide backup communications. I think the conventional communications have gotten a lot better. Which means that the bar of how bad a disaster has to be, for where hams can provide a service has risen. Right? That bar has risen.
(00:56:40):
The recent example I give of this, is the Puerto Rico hurricane several years ago, right? The entire island of Puerto Rico lost power and lost communications. It was a complete disaster. The ARRL sent down 50 hams with a bunch of equipment and said, "All right. Let us go rebuild communications on the island, and get them back up and running."
(00:57:04):
By some accounts, the hams that were sent were completely, or at least some of them, were completely unprepared for what they ran into. And it is not just a training issue. It is the attitude of, "I am a ham. I am the only option. Everything else is completely broken. You have to go through me." As opposed to, "I am here to help. Please tell me what you need, and I will see if I can provide it." Right?
(00:57:36):
So it was this attitude leftover from the eighties and nineties, where that actually was the case. The hams were the only ones there that were providing communications. That was true, but it is not true anymore. We need to get rid of that attitude. Do I think ham radio is useless in this regard? No. But I do think the bar has been raised to the point where we get called in is a much worse situation. So we need to up our game, if we want to still be useful in those situations.
(00:58:15):
Alternatively, we are still very useful in the smaller scope situations. I still think hams are very useful in a CERT type environment, my local community. Police and fire and Red Cross may still have communications. But if my local neighborhood has a power outage, we still want to be able to talk to our neighbors. Either hams or GMRS or FRS or something like that, some sort of a radio communication group is still usable in that situation. And I think really that is what we need to be concentrating on, if we are interested in emergency communications.
(00:59:00):
Having said that, I personally am not an emergency communications guy. I know lots of people are. I still participate in my area's check-in nets here in the South County, San Luis Obispo. I even run the net once out of every five weeks. But I am not one of the guys that fetishizes ham radio use for emergency communications.
EW (00:59:26):
Okay. Let us drop that topic. I understand where you are coming from, and I do not know, it sounds reasonable to me.
MS (00:59:34):
<laugh> Again, mark@halibut.com. Send all your hate mail straight to me.
EW (00:59:38):
Going back to the clubs, and not necessarily wanting to interact with humans in real time.
MS (00:59:44):
Yes.
EW (00:59:45):
Are there groups or forums for folks who are interested in the digital modes or the tinkering?
MS (00:59:53):
Oh, yeah. Yes. I do not know that it is going to be your conventional ham radio club. There definitely are conventional ham radio clubs that are less bad than others. I would look for college clubs. I do not know whether Santa Cruz, UC Santa Cruz, has a ham radio club, but-
EW (01:00:13):
They do.
MS (01:00:14):
They do? Okay. That is probably a good club to go to, because they are going to be younger. Students, student age people there, and you will be the old person in the room. It is kind of refreshing from a ham radio club perspective.
CW (01:00:29):
She is making a quite amusing face right now. I do not think she-
EW (01:00:33):
What about online? <laugh>
CW (01:00:34):
<laugh>
MS (01:00:35):
Online is also another good option. There are lots. Oh, it is like, "Oh, I do not want to show up in person. What are you thinking?" Yeah, there are definitely a lot of online clubs. Right before lockdown, I started a club here in the San Luis Obispo area, called CQ805. My goal was to make a online community, it ended up being a Slack workspace for hams in the area to get together and chat. And then we would get together at lunch.
(01:01:06):
It was meant to be ham radio clubs for the working stiff, as opposed to the retired folks, who always met for like breakfast on Tuesday mornings at 10:00 AM. "I cannot do that. I am working." Or the area's meetings at 8:30 PM at the County Comm Center across town. It is like, "Yeah, I got my kid at home. I got to go spend time with her." Those kinds of things.
(01:01:28):
The time that I had to go out and be social was lunch hours. So I tried to start that in the local area. If there are any listeners from San Luis Obispo, CQ805.radio. Honestly, you do not even have to be a local to San Luis. If you are just a ham and are looking for a community online, go check out CQ805.radio. Since the lockdown happened, that has become pretty much entirely an online community. We will occasionally get together for like a field day event.
(01:02:01):
There are a lot of people there that are coordinating the local AREDN network. A R D E N E R D E. No, it is pronounced Arden, but I think it is spelled differently. Anyway, like IP over ham radio stuff. So it is pretty active with that. Yeah. There are communities. I would not be able to tell you which one would be best for you. There are a lot of active channels on Reddit. I do not know which ones are good, because I do not frequent them a lot.
EW (01:02:38):
Okay. What about SDR? That is something I hear a lot. The software-defined radio?
MS (01:02:45):
Software-defined radio. Exactly that. So, <sigh>, okay.
EW (01:02:50):
He is like, "This is a whole other podcast."
CW (01:02:51):
It is not even in the outline!
MS (01:02:53):
It really is. Yeah. I warned you guys. <laugh>
CW (01:02:56):
We have not even gotten to satellite yet.
MS (01:02:58):
We have not even gotten to satellites yet. Yeah. SDR stands for software-defined radio. Basically think of it as like an analog to digital converter, that is sampling the RF spectrum directly. There are various different levels between like a hardware radio, where you have got RF in one side and audio out the other side, demodulated audio out the other side. And then what is called direct sampling RF, which is the opposite end of the spectrum, where it is an antenna into an ADC. And then the ADC is literally sampling the radio spectrum directly, and feeds it all into a very high bit digital data stream. And you do everything in SDR, in um, uh-
CW (01:03:47):
Software.
EW (01:03:47):
Digital software.
MS (01:03:49):
Yeah. Um.
CW (01:03:50):
Silicon. Trans chain digital.
MS (01:03:53):
What is the- It is like a special type of CP- DSP! Great gravy! Why did that take me so long? You do everything in digital signal processing.
EW (01:04:00):
That question came from Fred, who was interested in entry level options and licensing requirements, and I do not want to go too far into that. But it sounds like the QRP Labs might be a good place for kits, for various things if you are in an entry level and want to just check out what is happening. And you can listen without getting licensed.
MS (01:04:25):
Correct. So the QRP Labs is very hardware defined. He likes building things down at the individual component level. SDRs, if you want to get started with listening using an SDR, I would check out rtl-sdr.com. They make what is called the "RTL dongle." It is USB on one side and an antenna port on the other. I think they are about $25 or $30.
(01:04:53):
If you get the ones from rtl-sdr.com, they actually will receive the HF spectrum, as well as the VHF and UHF spectrums. They do something that enables the reception of HF, that a lot of other RTL-SDRs do not. Or RTL-based SDR receivers do not. So if you specifically want to receive HF bands, look for the rtl-sdr.com brand SDR receiver. They are very inexpensive, but they work reasonably well. They are not going to be the best ones on the market. But if you are just looking for something to get started and be able to tune around and listen, they are great. They do not transmit.
EW (01:05:41):
We have talked a little bit about licensing. Technician is the lowest level. It is a little bit of math and science and physics, but it is also-
CW (01:05:51):
Electronics.
EW (01:05:51):
Electronics. Has a lot of practice examples out there on the internet, some of which you have to pay for, but many of which you do not.
MS (01:06:01):
Oh, do not ever pay for anything, because you can get them for free. All the tests for the ham- Or at least in the US, every test question you will ever get on a ham radio exam, is known ahead of time. There is a pool of several hundred questions, from which 35 will be chosen for your exam. You do not know which question you are going to get, but every question you get is known ahead of time, including the answers.
(01:06:31):
So you can study all the questions and answers ahead of time. There are websites out there that will, for free, generate a random practice exam. So I would not ever pay for anything like that, because for the exam itself, it is too easy to script and the data is all public. There is no reason to have to pay for that.
EW (01:06:52):
Some of the questions have the same methodology to answer them, like converting from meter band to frequency. So some of these practice ones will tell you, "This is the piece you need to know." So if you want to pass the test, I am confident that those of you listening still, having gotten this far in the show, can easily get it done.
MS (01:07:22):
Yeah.
EW (01:07:22):
Okay. You have a company, which we were supposed to talk about.
MS (01:07:28):
<laugh>
EW (01:07:28):
Halibut.com or electronics.halibut.com.
MS (01:07:31):
Correct.
EW (01:07:35):
When you drove by, and we hung out for a little while, we saw this satellite optimized amateur radio, SOAR thing, that was very cool. But you have put a pause on that, and now headsets?
MS (01:07:51):
So, yeah. SOAR is, if there are hams who are listening, it is an appliance for operating FM satellites. Because building a station for doing satellites can be a bit of a chore. It is totally doable. But SOAR does a lot of the hard work for you.
(01:08:09):
It does the audio. It does the frequency shifting automatically for Doppler. It does all the calculations for that, and records the audio pass. It is a full duplex radio, transmits on one band, and receives on the other, at the same time. So it is just an appliance for operating FM satellites.
(01:08:29):
I ran into a problem with the output of the UHF transmitter not being stable, when put into a band-pass filter. And I cannot do it without filtering, and I cannot make the transmitter not oscillate when it is filtered. I have paid professional RF engineers to come look at this with me, and they are like, "I cannot tell what is going on. The transmitter module you are using is doing weird things."
(01:09:00):
So I have put that on hold for a bit, while I work on another project that is actually going to bring in an income, because I am living off of savings for the last year and change. What I am working on now is what is called "Open Headset Interconnect Standard." It is a published standard, for the interface between the radio and the user.
(01:09:25):
In ham radio, we have standards for things like DC power, all the commercial radios you get are going to be powered by 13.8 volts plus or minus 15%. A normal quote unquote "12 volt supply." They may have various different connectors, but it is easy to convert from one connector to another, because it is the same electrical standard.
(01:09:46):
Similarly, on the RF side, we have standardized on 50 ohm coax, and the coax may have different connectors, but because it is all the same electrical standard, it is easy to convert from PL259 to BNC or whatever, because it is the same electrical standard.
(01:10:03):
We do not have that same kind of standard between the radio and the user. There are so many different types of microphones. Is it an electric mic or a dynamic mic or a carbon mic, or is it a line level input? Is it speaker level output, or is it headphone level output, or line level output? If it is speaker level, is it ground referenced, or is it push-pull? There is just no standardization.
(01:10:28):
And I have not even gotten into physical connectors. There are so many different types of physical connectors. And then even when the connector is the same, the pinout is different. It is maddening. So if I come into an environment where I have got my headset that I have spent good money on, several hundred dollars on a really good headset with headphones and a microphone. It has got its connector on it, or series of connectors, and I want to plug it into your radio, I need to have the very specific adapter that goes from that headset to that radio.
(01:11:04):
It may be different than the headset that you have. I do not want to put your headset on my head, because it has got your ear goobers in it. And I do not want you using my headset, because I do not want your ear goobers in my headset. Right. And "ear goobers" is going to end up in the glossary of this document, I know it, as an explanation of why we do not want to share headsets.
(01:11:27):
You end up with this full mesh of adapters, between every single different type of headset, and every single radio. In your own personal home shack, that is not that big of a deal, because you have got a relatively static and small number of devices. But if you go into a multi-user environment, like a club shack where you have got 50 club members, they may have ten different styles of headset, and you have got four or five different radios in the club shack. That ends up being a lot of different adapters.
(01:11:58):
Or an EOC, where you do not know what radio you are going to be assigned to. EOC is an emergency operations center. Again, back to the emergency communications thing. You do not know what radio you are going to be assigned, but I definitely want to use my headset, on whatever radio it is that I sit down at.
(01:12:15):
So I have designed this standard interface in the middle, and we make adapters on both sides of this standard in the middle.
(01:12:26):
So I make one adapter that goes to this particular radio, and it adapts whatever the interface on the radio is to the OHIS socket. The OHIS is the standard. Then I make a second adapter that goes to my headset, that converts whatever my headset is, to the OHIS standard. That adapter on my headset stays with my headset, and I never disconnect it and give it to somebody else. And that adapter on that radio, stays with that radio, and you never have to disconnect it because somebody else brought their headset in.
(01:12:58):
Now that I have this standard interface in the middle, I can connect my headset with my OHIS adapter, to any radio that also has its OHIS adapter. It allows complete interoperability from any headset to any radio.
EW (01:13:18):
Okay. That makes sense. Why has not somebody done it before?
MS (01:13:22):
<sigh> I do not know. I have heard a lot of people come to me and say, "Oh my gosh, we have this problem all over the place. I very much want this." So right now, I have written the standard, although it is still a work in progress.
(01:13:39):
The standard itself is open, so that definition of that middle layer is a completely open standard. I do not want to own licensing on it or anything like that. I want everybody to use it. The devices that actually implement that standard, the adapters on either side or anything that is in the middle, those can be proprietary to the companies that make them.
(01:14:01):
For example, Halibut Electronics is working on, I am working on, radio side adapters and user side adapters, the headset side adapters. I just looked earlier, I got prototypes that have made it into the United States. They just left LA this morning, from the assembly house in China. So I should be getting them early next week, to continue developing that.
(01:14:23):
I am hoping that I will be able to click the button and say, "Manufacture a hundred of these for me, and send them to me and I will start selling them." The devices themselves are proprietary, but the interface that they use is open, and anybody can make devices for it.
EW (01:14:44):
Cool. I hope that takes off.
MS (01:14:45):
Me too.
EW (01:14:46):
Standardization really is very useful, especially if you can agree upon only one or two standards.
CW (01:14:54):
<laugh>
MS (01:14:56):
<laugh> Yeah, I am okay with multiple physical standards, because it is easy enough to build an adapter if it is just wires. It is when they are different electrical standards, that is a real pain in the butt.
EW (01:15:06):
Yeah. Okay. I have a couple more questions for you. I know we are way over time.
MS (01:15:10):
Way over time.
EW (01:15:12):
You have a podcast that you are on frequently. It is called "Ham Radio Workbench."
MS (01:15:17):
I do. Correct.
EW (01:15:17):
What is it about? Who is its intended audience? And sorry, how big of a lawn do you need to mow, for the average Ham Radio Workbench podcast episode?
MS (01:15:30):
<laugh> Yes. Ham Radio Workbench is a technical deep dive into topics of interest to the amateur radio, is the podcast opening line that George usually says.
EW (01:15:42):
Wait a minute, does he stop there? To the amateur radio?
MS (01:15:44):
To the amateur, to the radio amateur.
EW (01:15:48):
Okay. Because I just have this idea of little radios listening to you.
CW (01:15:53):
Oh.
MS (01:15:53):
Yes. Well, I would be okay with that.
EW (01:15:57):
Okay.
MS (01:15:58):
Okay. Did I say, "amateur radio?" I meant to say, "radio amateur."
EW (01:16:02):
Sorry, I should not have hassled you.
CW (01:16:04):
<laugh>
MS (01:16:04):
We are going to roll back the tapes. Anyway, we talk about all kinds of technical topics, from what kinds of tools do you use, to 3D printing, circuit analysis, circuit design? A lot of times, it is typically chopped up into two different pieces.
(01:16:23):
The first one is the "what is on your workbench," where we go round table, around all of the hosts of the show, and we talk about the things that we have been working on. It is a very casual- Tends to be very long, even though when we say, "Okay, we got to get through this quickly."
CW (01:16:43):
<laugh>
EW (01:16:43):
<laugh>
MS (01:16:45):
Hour and a half later, here we are talking about what is on our workbench. It is a lot of, what cool things have we seen lately? What are we working on, yada, yada, yada. And then the second half, we usually have some topic that we are talking about. Recently we recorded an episode on what does it take to build a repeater? What are all the different parts that go into building a repeater? I did an episode on OHIS.
(01:17:02):
We have done episodes on POTA, Parks on the Air, which is a program to encourage people to get their portable radio, hike out to a park somewhere, set up an antenna, operate a bunch, talk to other people, and then pack up and go home. You end up getting points for the more contacts you make, and it is gamified ham radio, and stuff like that. We have done topics on 3D printing, technical topics of interest to the radio amateur. It is intentionally very vague.
EW (01:17:41):
Cool. I mean, ours is sort of about engineering and people, and sometimes we have sci-fi authors.
MS (01:17:49):
Oh, nice.
EW (01:17:50):
It really is not focused. Well, it is focused on people I want to talk to. <laugh>
MS (01:17:56):
Exactly.
EW (01:17:57):
Since I am in charge of scheduling.
MS (01:17:58):
<laugh> It is just an excuse for me to get people on the show.
EW (01:18:01):
It is just an excuse for me to chat with people. Ask them questions that if I ask them just normally, they would be like, "Why are you so weird? Why do you need to ask me these detailed questions?"
CW (01:18:11):
<laugh>
MS (01:18:13):
Mischief asks, "How big of a lawn do you need to mow, for the average Ham Radio Workbench podcast episode?" Our show goes long. Two hours is considered a short show for us. We have been known to do three, three and a half hours at times.
CW (01:18:30):
I cannot sit down that long!
MS (01:18:31):
Yeah, neither can we. We take breaks and do potty stops in the middle and whatnot. The joke is always that our listeners come back to us and keep saying, "No, keep it long. We like it. I have got a huge lawn I need to mow, and I put your podcast on while I am mowing the lawn." So the joke has become that we measure the length of our show in acres of lawn. It is typically about an acre of lawn per hour.
EW (01:18:58):
Ours is, I think is usually measured in baskets of laundry.
MS (01:19:01):
Ooh, that is a good one. Yeah.
CW (01:19:02):
<laugh>
EW (01:19:05):
All right, Mark, I think that we are going to close up our show now-ish. Do you have any thoughts you would like to leave us with?
MS (01:19:15):
Just the same thing that I end all on my podcasts with, which "is be good humans". There is not enough of that out there these days. We all try, I know we do and that is good, but keep trying and keep encouraging others to do so, and keep making a difference in the world.
EW (01:19:34):
Our guest has been Mark Smith, N6MTS, known as SmittyHalibut on most social media, including YouTube, Mastodon, and GitHub. You can find his products on electronics.halibut.com, and he is the host of Ham Radio Workbench, if you want to hear more from him.
CW (01:19:52):
Thanks, Mark.
MS (01:19:52):
Thank you.
CW (01:19:53):
I think I have learned things that I needed to learn, and you have explained some things that I never understood very well, in ways that I now understand them. So thank you.
MS (01:20:01):
You are very welcome. I am glad to be here. Thank you all for inviting me.
EW (01:20:06):
Thank you to Christopher for producing and co-hosting. Thank you to our Slack group, our Patreon listener Slack group, for their questions. And of course, thank you for listening. You can always contact us at show@embedded.fm or hit the contact link on embedded.fm. I do not have a quote to leave you with this week. I think Mark's, "Be good humans," is probably a good place to leave it.