Episode: 2648
Title: HPR2648: Explaining the controls on my Amateur HF Radio Part 1
Source: https://hub.hackerpublicradio.org/ccdn.php?filename=/eps/hpr2648/hpr2648.mp3
Transcribed: 2025-10-19 07:00:53

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This is HBR episode 2648 entitled, Explaining the Controls on My Amateur HF Radio Part 1,
and in part of the series, HAM Radio, QSK. It is hosted by MrX, and in about 27 minutes
long, and carrying an explicit flag. The summary is, I attempt to explain the Controls on My
Amateur HF Radio. This episode of HBR is brought to you by archive.org.
Support universal access to all knowledge by heading over to archive.org forward slash donate.
Hello and welcome hacker public video audience. My name is MrX, and welcome to this podcast.
As per usual, I'd like to thank the people at HBR for making this service available to us all.
HBR as a community podcast, created by the community for the community. I mean you could
contribute to just pick up a recording device, you could use an MP3 player, your phone, tablet,
computer if you have such a thing these days. Who has computers these days? So there we go.
So I thought, in this episode, I thought for all you budding hams out there, or for amateurs as we
say in the UK, or people must be thinking about becoming an amateur. I might cover the controls
on my Amateur HF Radio. It's a Kenwood HF Transsever TS940S.
And some of these controls these days, you won't see in a typical modern radio,
but a lot of them you will. And the thing about this video that I particularly like is there's no
menus, because it's a large radio, there's enough room on the front panel to
have one control that does one thing. You don't need to go into layers of menus to reach any of
the features. And I think sometimes some of these features that they have in the modern
radios are a bit gimmicky anyway. I'm sure some of them are very useful to have and said that.
So the radio itself, it's the front panels,
how can I word this? It's the distinct regions on the front panel.
One, two, depends how you split it, I suppose. Basically on the left hand side is generally
for controlling the transmit section, output section of the radio. The middle section is
predominantly to do with changing modes, changing bands, changing frequency. And the right hand
side of the radio is predominantly for receiving filters and such, to help you pick out a signal amongst
all the noise. That's the biggest problem when HF, of course, you've got lots of lots of noise to
contend with and you want to try and filter all that out. So I think there's one, two, three, four,
five, six, seven, eight, nine, ten, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, two, three, two, four, five, six,
two, seven, eight, two, nine, ten, one, two, three, four, eight, nine, ten. That's a bit of 50
controls on this thing, something like that. So some of them are, as I say, you won't find
in a modern radio and tell them I don't actually know exactly what they, you know, I've got an idea
of what they do, but not exactly. It seems a bit strange because it's very unusual for me to have
something that I don't understand how to operate properly, but it was kind of set when I got the
radio, radio, what it's second hand and I've never really touched some of these settings and
by any will cover it anyway. So starting at the top left hand corner, the big main button
is power and it's kind of obvious for that, doesn't it? It turns the thing on and it's a kind of
latching push button, you push it in, it stays in, you push it again and it springs out again.
I think I remember reading somewhere that if you turn it off or not off none too quickly,
whether in a short period of time it can go into a funny mode and confuse the radio and you
have to unplug it and plug it back in again, but that's just a by the by. Because of the age of
the radio, when you turn it on, you hear a pilot really clicking and clattering inside it,
it's fairly quiet really, but I mean nowadays everything would be solid state or maybe the odd
trend just to be very small and quiet so you wouldn't hear it. So we'll go ahead and I'll turn
that on, let you hear the click if I can, and that's it back off again. So I think that's
the power button. Next to that, next button along in the top row, top left is a button called
timer and it's a thing I've never used, but the radio is able to turn itself on and turn itself
off at certain times. I'm dare say if you're wanting it by our bedside and want to be waken
generally by some soothing morse code, it would be ideal wouldn't it? So maybe you'd want to go
to go to sleep with the soothing sounds of morse code in your ears, maybe not. Right, so below that,
you've got the next row down from that. The first button is Vox and Man, and so if you push
the button and it's the same sort of thing, it pushes in and it latches. In the Vox position,
voice operated switch, and basically if you start talking into the microphone, the transmitter
or transmit, and when you pause or drop back out into receiver game, so you don't need to push
the PTT, I don't need to push the transmit button on the microphone, basically.
And if it's a man, then I presume that's manual. Next button along from that is full and semi.
Now what the heck does that do? I think that's to do with morse code. I think if it's in semi,
if you're using morse code, it's transmits them, you stop, it drops back into receiver game.
So in would be full semi. Now I think that's what that's to do with.
Probably the no-everything did. The next one along from that, third in from the left,
second row. The top is monitor and off. So if monitor or money, if that's active,
pushed in, then when you're talking to the microphone, your voice can be heard in the speaker.
So if you've got headphones on, you can monitor your own voice and it's
could be useful. Probably not a good idea if you're using a hand microphone and an external speaker
because you can get feedback. And obviously the off position that turns it off, I've got that off
by default. And the final button on the second row down is dim and normal. And that dims the display.
I think it, not only dims, there's a, no, I'm not sure. It's not LCD. It's not LCD. It's not
LCD, is it? There's no, it's not Nixie tube, is that, is that kind of, it's a bit like an LED,
the display of it is LED display, but if I'm funny feeling it isn't, and anyway it dims that,
and it also dims the, I think it also dims the back on the meter. It's got a nanologue meter
that wavers up and down my signal and whatnot. So that's what that does. Okay. So if we go to the
next row, third row down, the first key, let's turn it back off again, is, oh no, quite often by
the way, I tend to use dim, because I think I'm sure I heard someone say that it puts less
strain on the, but obviously they'll put less strain on the, on the, on the, on the, on the meter,
and possibly on the display as well, stop it burning in sort of thing. I don't think it's an LED,
I'm sure it's something else. Fluorescent tube, kind of fluorescent tubes. But it,
um, as the reader was quite old though, you know, I wanted it to last, basically, and strain it
as much as possible. Um, what I think, I don't actually, what age it actually is, but I'm sure you can,
look, I might, if I look in the, I might put it in the notes if I got a chance, how old did I do it?
It's pretty old these days. It is, it is transesterized, but it hasn't got valves or anything in it,
but it was just at the period with the switch from, I think, from valve, like, to, uh, transistors,
to adjust this microphone here. It's, it's, uh, something I bit, a headphones actually a bit,
a bit of a big side for me. Um, so the third row down, uh, the first, uh, button you come to,
again, it's a latching button, you've got send and receive. And I, I guess if you had a,
a desk mic or, um, or if you were, um, using a morse key, you could lock the deal into
transmit. And then if you were, uh, either sending some morse code or using a desk microphone,
you wouldn't need to hold the button in for their transmitting. And at the end of it, you just hit
the button and it drops out, the button pops out and it goes back to receive. So of course, I never
use that button. Um, there's an auto and through. And I haven't got to clue what that does.
Um, maybe should I read a bit to reset? I thought, I thought there was only the odd button,
but it just spires now to look at it. There's so many buttons on this radio that, um,
it's, uh, it can be a bit bewildering if, if you haven't, I mean, when you first look at it,
it's sort of thing. Um, um, I have to split this, uh, podcast into more than one, um,
section, which I'll, uh, which kind of love. Uh, the next button, along from there is Narwin Wide.
Now, uh, this at that time, um, the manufacturers, the, the, I don't know if they still do this
thing, but there was extra options you could buy the times, you could be a bumping a price up or
you could buy it later on, you could buy a, uh, a filtering board. And if you bought this
filtering board and you could open the case up and, uh, and fit this board. And then that, that,
this Narwin Wide switch would operate. And so that if it was a noisy signal, you could hit the
narrow button and it would, it would reduce the bandwidth of the receiver so that you wouldn't,
you could, you would hear the quality of the audio would be impaired, but at least, you know,
you wouldn't hear the interference above and below the signal you're trying to listen to.
So, um, so that was that Wide and Narrow, but it does nothing because I haven't got that board
installed, uh, I bought it secondhand radio and just came with what it came with.
Um, so the next controller long is a, is a switch, um, and a tenuator, it says ATT,
which stands for a tenuator. And, uh, it's marked with a 0, a 10, a 20, a 30, and then below
the 30 is brackets DB stands for decibel, decibel. And, uh, this, uh, attenuates, uh, signals. So,
if a, if a signal is coming in too strong, it can, it can become distorted and you can, you can
click on some, um, attenuation, so if I just, that's, that's a switch, turning. So, that's handy
if you get a strong signal coming in. Um, sometimes actually, uh, it, um, it, um,
either there's not too strong, it sometimes quite nice to, to attenuate things a little bit, um,
if, if the signal is not varying too much and, and, and strength, um, because the next controller
long, um, it is, is AGC auto gain control, and I'll explain that in a minute. So, uh, it's got,
I'll explain what I'm talking about with a tenuator and AGC in a minute, but if you, the AGC's
got three positions, uh, it's off, fast, and slow. So, what the auto gain control does is,
it's a bit like, um, um, an automatic attenuator, uh, uh, uh, uh, or, no, it's, uh, I think I,
adjust the, is it, the, is either the, could be a signal that could be audio, is it, audio
that actually adjusts, or is it the signal? Basically, it turns again up and down, sort of, if,
if the signal is too strong, it, uh, it, it, it, it, it, it, it, it, it, it, it, it, quiteens it a bit.
But what happens is you hear the, um, the back-down noise coming up and down, and, and it can be a bit
annoying. So, if you click into my tenuation, so the signal drops a bit, then the, the, the gain control,
doesn't ramp up and down so fiercely, and it's a bit more pleasant to listen to,
and, uh, the reason you, you might want slower, faster, you see it, if, if, if the signals fitting
in and out very quickly, you might want to use, uh, fast, but generally, uh, it slows,
absolutely, if you enter the gain, just, just, just, just out slowly over a number of,
a number of seconds, uh, it's a bit, a bit nicer on the, on the ear, so that's why you've got off,
fast and slow, and if you had it off, then you'd be turning a volume up and then all the time, uh,
trying to, uh, because if the volume of the, the received signals would be all over the place,
basically, so it's a very handy feature to have the AGC. Um, the next controller long is called
meter, and it has one, two, three, four, five, six positions, and, um, some of these things,
you wouldn't get in a modern radio, and they're a hangover from, uh, hangover from a bag on era,
when, um, radios had, uh, had valved, um, transmitter tubes inside them, basically, um,
I'll explain in a minute, gonna get to these, these, uh, options, but, um, the first few,
um, are quite normal, you've got, you've got the first one is comp, which is, uh, compressor,
um, so that, that allows you to see, um, it's, it's used in conjunction with another control,
which I'll cover later on in a minute, uh, but you can adjust the compression of your audio,
so that allows you to kind of boost or compress the, the peaks and, and, uh,
troughs of the audio, so it's a bit like, well, it's audio compression, you do, in, in,
in audacity, you know, it means that the, the, the difference between the loudest piece,
because of audio and the quietest piece is compressed, and it makes the, the average audio sound louder,
um, you know, it's, it's used to devastating effect and adverts, by this carpet for 1999,
you know, that's what I think, you know, sounds out loud, you know, um, that sort of thing.
So, uh, compressor or comp, next thing is ALC auto-limiter control, and, um,
that tells you if you're driving the radio too hard, and you need to back things off a bit, um,
again, I think that's used in conjunction with, uh, another control, the processor control,
which I'll cover later. Uh, next one along is power, and in fact, that, that generally is where I
leave the, the, um, the switch, um, I mean, generally, I, I, a lot of these controls are just
set and left and never touched, um, but, um, because, um, this is an early transistorized, um,
radio, I think it might even be the first, um, attempt that came, we've made to, just a transistor,
radio, the, uh, transistors are a bit fragile, um, and can be damaged easily. So, I tend to run,
although the radio is rated at 100 watts, in fact, it might even be a little bit more than 100
watts, I, uh, I run it at 70 watts, um, maximum, so that, um, it's, um, it's, um, it's, uh, it's a gentle
life. And I think these, the, the, the kind with 940 s's, well, there are, well, it's a wonderful
radio, um, they were known for, um, output stage failure, you know, the, the output transistors failing.
So, just by, just by judging it a little bit gentler, um, it, um, I've had no problems with this at all,
I completely fault this, um, in the previous scenario, but I was a previous one that told me that
to, he never ran at past 70 watts, and that's why it's still working today.
Um, the, the, the next, um, position round it is SWR, which stands for standing wave ratio.
And that, um, allows you to, um, measure the, the, uh, standing wave ratio is, uh, it's a, um,
I can explain this. It's, um, it shows, um, how much power is being reflected back from the antenna
if it's not tuned properly, basically. So the lower that figure is, the better tuned your antenna.
And you don't want, um, signal returning back up the, uh, antenna feed back into the radio.
It can cause interference in the house and the, the other TVs and whatnot, and it can damage your radio
and blow up these, um, delicate, um, power transistors that I was talking about.
So, um, some of these pieces are quite critical related to the operation radio, uh, if you don't
use them, but, but, but once I set it, you just let it leave them alone. Uh, next I see, um, I think
I should do with the, the final stages, the, uh, and, and put current, maybe, um, you know, I,
I think when you had, um, input current and the next one is VC voltage, something, uh, not sure.
But, but basically, when you had a, a valve radio set, you know, you had to, you had to check
and monitor the, the voltage is coming in and out of the, the voltage is in current,
it's coming in and out of the valve and you could blow the thing up. And I think that's why
these are here, but I've never really paid any attention to these at all. Um, so it's a bit of a gimmick
I think in reality. As long as your SWR is okay and you, uh, you, you don't, I am set your power
level too high then you're going to be okay really. Um, so that's, that's, that's, we'll go down to
the next, uh, row. So there's a, there's a row of buttons below, um, the top row of, um,
that I was just, the, these, these three controls I was talking about. And, uh,
NB1, NB2 and PROC. And the, these both, there's always three, um, switches can be pushed in
or out and they're latching just like the other ones I was talking about.
NB1 and two are, are noise blankers. So they, they take out, um, repetitive pulse noise type
interference, see if it's a car idling outside and it's, you know, you're in, you're in, it's kind of
ticking noise, you might be, and knock it out by pushing one of these noise blankers in. Now,
the two work differently and some work better for some kinds of noise and other works better
for another kind of noise. And I can't, uh, it was a long time to salute it to this.
Um, I think when one's better with short, very short, um, pulses and ones work better with longer
pulses or the frequency of pulse, of pulses or noises or something, something to do with that.
What's terrible, uh, review this as, isn't it? Um, and the final one PROC on and off is,
I think that's to do with the, uh, processor in the, which is to do with the compressor, you know,
if you turn that on and you've got the, the speech processor or compressor turned on so that you're
out, voices, um, boosted, you want that on or off. Um, I think she, wonder, I wonder why the, uh,
since it NB1, NB2's for reception, should really be over now. That's how you do the review.
It's certainly the PROC. The processor button should, uh, make sense to be next to all these other
transmit, um, functions. Why do the teni-tar things do with reception? So that's not good. This is
confusing. So all right, okay, the, uh, the next row down from that, there's a, there's a,
there's a, forgot to mention, there's a phone socket for less than the headphones on that row.
Uh, it's the final row, uh, on the, on the left hand side, starts with a microphone socket.
That's just for whatever microphone you have attached. I've just got the standard handheld
can-wed microphone. Uh, next to that is a rotary control, fully variable NB level, noise
blancher level. And you can adjust how fiercely the noise blancher takes out the, the, the, the pulse
tone, the pulse noises that are coming through. And, you know, the more aggressive it is, the more
it did deteriorates, the quality of the, the, um, the audio, generally speaking, these noise
blancher things just don't work at all, usually a waste of time. But actually, in this video,
they do actually work. I have, I have seen me using them on, on, on occasions. I've had multiple
readers in the past with these in noise blanchers and they're just a waste of time. But, um,
I think it's quite, it's quite good circuitry in this one. It does actually make a difference.
So that's noise blancher. Next one along is, it's a kind of rotary control with an inner and outer
section tape. And it's called Processor. And they've got Processor, the inner one is Processor
Input and outer one is Processor Output. And I think it's quite a sophisticated, um, speech
processor compressor on this video is, I think it's an RF Processor, speech processor. And,
you know, I have never touched that at those two controls in an outer, I've left it where it is.
Currently sitting at, uh, three, I think, something like that. And when you're looking at, uh,
if you put the meter onto ALC, Autolometer control, you can check your not, um, along with compressor,
you can check that you're not driving the radio too hard, basically, and causing interference or whatever.
As I say, how much you still get at this on a modern radio, I'm not quite sure.
Um, next along, uh, mic and power. Uh, I've never touched a microphone gain since I bought the radio.
It's sitting at two and the power is sitting at six. And that goes in about 70 watts, something like that.
Um, it's, it's got a really nice, uh, I've heard other camewood radios and they've got the camewood
nine forties. And I've got a lovely mellow sound to them. I think some people prefer, you know, quite a sharp
um, audio, sharp crisp audio, um, which is great for, um, you know, working distant, long
distant stations and, you know, breaking into the, you know, into, you know, get a very weak signal
through. But this radio has got lovely mellow audio, like the, as I say, BBC quality,
bassy and, and rich and mellow and, uh, it's very, very nice, but maybe no ideal for, for, um,
for, you know, DXing and time to try to get out of the noise, I think, you know, it's, um,
but uh, that's by the by. Um, so that, that's all the controls on the left hand side for the transmitter.
Um, talked about. Okay, so that's about it for this episode.
It's sort of, it went on a bit longer than expected, so I think it's a good place to stop it.
So this will be part one, um, I know Ken likes multi-part shows, so that'll please Ken. Um, if you
want to contact me, I can be contacted at MrX at hpr at googlemail.com. That's MRX ATHPR, the
art symbol, googlemail.com. So until next time, thank you and goodbye.
You know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know, you know
you know, you know, you know
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