Episode: 4192
Title: HPR4192: Replacing backup batteries in my Kenwood HF Radio Part 2
Source: https://hub.hackerpublicradio.org/ccdn.php?filename=/eps/hpr4192/hpr4192.mp3
Transcribed: 2025-10-25 21:05:01

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This is Hacker Public Radio Episode 4192.
For Tuesday the 27th of August 2024, today's show is entitled Replacing Back-Up Batteries
in My Kenwood HF Radio Part 2.
It is part of the series Ham Radio.
It is hosted by Mr. X and is about 13 minutes long.
It carries an explicit flag.
The summary is Replacing Batteries in My HF Amateur Radio T.S. August 3, 2024.
Here's Replacement of the Clock Battery.
Hello and welcome Hacker Public Radio Audience.
My name is Mr. X and welcome to this podcast.
As usual, I'll let this up by thinking if you play HPR for making the service available
to us all.
HPR is a community-led podcast provided by the community for the community.
That means you can contribute to.
So why don't you pick up a microphone and record something and send it in.
I'm sure that must be something you can think of to send in.
If we all send in just one show a year, there will be more shows and we know what to do
with.
And they're always looking for shows.
And they're also going to create the live effort to try and slamline the process.
It's really quite easy to do.
So why don't you have a go at it.
So yeah, anyway, this episode is part 2, which was originally recorded.
I think it was just before Christmas actually, 2023.
And will I replace some batteries, some backup batteries in my Kenwood TS940 S, which
is an 8HF amateur ideal set.
And these backup batteries hold up the one that I've been replacing in this episode.
It holds up the clock time.
So this covers replacing the battery, the existing battery with a new battery.
And the difficulty is long away.
This shows up this one is a wee bit shorter than the previous one.
So just sit back and enjoy.
Okay, so here's a wee pro tip.
I just thought about it.
I got a replacement.
I think I did.
I just went on an EBN look for Kenwood TS940S back at battery.
And discovered somebody who was selling them.
I should admit that they were new.
And for the original, that would be an 1986 vintage, or very abouts.
I'm not sure what year's the radio was on over that year, anyway.
I noticed that the invoice mentioned CR2032.
It did mention the number of radios that were fitted.
TS430, 440, 330, and 940, memory backup battery.
And that says CR2032.
Well, there's a standard CR2032s.
I'm guessing that they're not original.
Okay, Kenwood batteries, if they were to be jiggered by now.
Probably 2032s.
I'm CR2032s.
It's a standard that batteries use for a number of things.
They're used in air tags, for example.
And whether these have been, they've put, there's like,
two metal strips welded onto, to allow you to solder it onto the PCB.
And there's yellow, heat shrink type round, round outside.
I guess that's the topic.
Shortening it against ending.
Do look a bit.
Just looking at the, do look a bit thinner than this substantial than the,
the battery that was, indeed, just comparing with 2 just now.
But still, I'm August hand, I don't leak actually.
And I think, I did try to take a whole of, you know,
Kenwood parts or whatever, Kenwood original parts,
but I mean, it's, I think it's long gone.
Okay.
Interesting.
Packaging is, it's a, kind of like a cellophane sort of sticky,
to keep it in place.
I haven't opened it incorrectly, I think that was my fault actually.
Oh, that's interesting.
So, these have been cut out of a pack by the look of it,
with a piece of tape over the top to hold it in place.
I'm not sure what all that means.
But what I was thinking was I should have,
I should have checked these batteries are, are okay.
So, I've got my trusty Fluke 77 digital voltmeter here.
And if I place it, it says plus.
Obviously, the digital multipliers doesn't matter,
the clarity, it'll compensate for that.
I'll put them in the correct way.
Just do that where I can check the clarity, the battery's correct.
So, plus there.
Minus there.
3.35 volts DC.
And I'll just check was it a positive voltage?
Yes it was.
And so, that is as per marked.
So, I can get again a plus on the top,
and put one contact on that, one contact on that.
3.3, yeah, they're both the same, 3.3.
And a plus is on the top.
Then we'll just check, I assume the plus is on the top,
on this one.
No, no, no.
Of course, maybe it's another plus is on the bottom.
And the rest thing, plus is on the bottom.
Hmm.
Plus, it says on the bottom.
Yeah, I guess I could put them in, put it on the other way round, I guess.
It's maybe just a way it's mounted in the tray.
Yeah, I'll take a photograph of the two batteries,
so you can see that, just fun to seek.
Right, I'm going to take the, I'm going to remove one of the batteries
just to see, to confirm, actually I could hold it up against it first of all.
Yeah, that might be a bit, a bit short actually.
Hmm, that's not good.
It looks to me like the whole pitch for the two contacts is too small.
That's not good.
That's not good at all.
So the positive is on the bottom.
Yeah, that's not going to a bloody fit.
Oh, thank you.
That's really handy.
I guess I should have checked all of this before I took the leads to the bits.
We'd have to extend that, I think.
I wonder what, I just, I wonder what the battery voltage is.
It's all a bit planning isn't it, and I haven't planned.
It's all a bit planning.
This is all going to have a bit of a laugh while I'm doing this.
So, put my probes on there and there.
Try again there and there.
Yes, point two of old.
I would say this battery is pretty ghost.
Yes, point two of old as opposed to three point,
whether it was three point three, was it something like that?
I'll just have a check at this.
Is there any other writing on the board?
Not seeing anything.
These posts look quite thick and I don't think it's a good idea to be a bit bending them.
I think I'm going to have to put a small link, a small wire link or something across.
I think that's how we'll do it.
Use a small wire link.
That's probably the best way to doing it.
Now, I think I have a soldering tool or a solder sucker.
One somewhere.
I'm sure I do.
I came across it recently.
Now, of course, if I need it, I can no longer find it.
I'm sure some people have got a beautifully stocked tool box with everything,
all the individually separated and whatnot.
Take it out.
Oh, here we go.
The soldering tool or solder sucker.
I guess a bit of tumma soldering out on.
Right.
I've got some fresh solder here.
I had some other solder somewhere around here, I'm sure.
Because that one looks like a packet I haven't used before.
I'm waiting in the soldering and heating up.
Well, it takes very long.
I could choose.
I've just found a resistor with quite reasonable thickness of legs on it.
I think I could perhaps use that to fashion an extender for the lead.
Make a link.
Yes.
I'll see how that goes.
So, I think what I'll do is I'll take this battery back.
That's going to take longer than I expected.
Place that there and safely out the way.
Eye glass and our soldering tool.
Soldered.
Okay.
Where's the end?
Let's see if I can find another bit of solder.
Okay, so that's me.
I've managed to just solder the battery that goes on to the clock timer.
I haven't done the one for the frequency PLL circuitry.
It took a bit longer than I expected.
I don't think I hadn't planned this properly.
So there's less to plan things out.
I don't have enough space to work on.
Lighting was terrible.
It was directly above me.
Every time I leaned over the radio I was in my own shadow, so that didn't help.
And then of course the battery was the wrong physical size.
I had a joining link to increase the pitch of the holes so that we could attach to the two poles.
I'll take a photograph.
It's not my most brilliant job, my most types of job.
I think also I used that.
I don't know.
I was having difficulty getting the solder to properly adhere to the post.
It wasn't flown properly.
I was going to die joints as well.
So I don't know whether the terminal of the battery had a contamination or what it was.
I'm not quite sure.
And it happened to balance a torch above the top of the radio.
He held in place with a screwdriver so that I could eliminate the battery.
I think it would have been better doing this downstairs.
I think whether it would have been more space.
I have this recollection.
I had the same conversation many years ago when I did another HPR show.
And I was talking about the radio.
Or got his figure recollection.
But it all blends into one.
Anyway, I think I may leave it at that.
Obviously record the putting it all back together again.
I do want to do the other battery though because I don't want that to fail either.
I don't want to waste it leaks.
But I've kind of run out of time today.
So maybe for another day.
Let's see.
Okay, I think that's about it for this episode.
If you want to contact me, I can be contacted at MrX
at hpr at www.wglmail.com
That's MRX ATHPR
www.theatsymbolgooglemail.com
So tune in next time for another exciting episode of
Battery Replacement on a came with TS940S.
Bye for now.
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