Episode: 4212
Title: HPR4212: Replacing backup batteries in my Kenwood TS940S HF Radio Part 4
Source: https://hub.hackerpublicradio.org/ccdn.php?filename=/eps/hpr4212/hpr4212.mp3
Transcribed: 2025-10-25 21:27:34

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This is Hacker Public Radio Episode 4,212 for Tuesday the 24th of September 2024.
Today's show is entitled Replacing Back-Up Batteries in My Kenwood DS940SHF Radio Part
4.
It is part of the series Ham Radio.
It is hosted by Mr. X and is about 20 minutes long.
It carries an explicit flag.
The summary is Part 4 deals with getting access to the PEL backup battery.
Hello and welcome Hacker Public Radio audience.
My name is Mr. X and welcome to this podcast.
As usual, I'd like to start by thanking the people at HPR for making this service available
to us all.
HPR is a community-led podcast provided by the community for the community.
That means you can contribute to why you pick up a microphone, your mobile phone,
a computer if you've still got one.
Something like that, I record something in Send and a Show.
The people at HPR have gone to a great deal of effort to make it very easy to send in
a show.
You might actually enjoy it and you can have it get addicted to it.
If you go to the show and go to the website and go to the give shows section, I think,
you'll find there's a list of ideas for new shows if you haven't contributed one before.
You can just tell us your story and how you found the website, the HPR or how you got
into tech or whatever.
There's lots of ideas you can come up with.
If we had just one show from every person who listens to HPR would have more shows, then
we know what to do with.
When you give it a go, you might even enjoy it.
This particular episode covers a continuation of my series on my Kenwood HF High Frequency
Amateur Radio, TS940S.
It's a big base station Amateur Radio set, which I discovered had a battery failed in
it that holds up the clock.
There's actually two batteries in the radio and this covers the second battery.
The second battery being located in the PLL unit, Facebook loop unit, which is a bit
of a pain to get to.
Anyway, set it back and enjoy.
Okay, so this is replacing the back at batteries on my Kenwood HF TS940S radio.
Not sure whether I'll just post these two separate shows or what, I'm not quite sure yet.
But I'll not go into this one as much detail as I did with last one, I think, because
I think the radio is stitching to over an hour, as it has been quite long, I don't
need to bore you all.
So I've got the top lid loose and I'll take that off and I'm now going to try and replace
the battery in the frequency PLL board.
Basically, PLL phased lock loop, just in case you're wondering.
Right, so the battery is underneath the speaker, basically.
And in the video, which I'll include in the show notes, the chat mentions that there are six
connectors to remove before you can lift up the mic with the speaker.
He says they're all marked F, I can see, some of them marked F enough,
one of what F stands for frequency, frequency unit, I don't know, no idea.
Anyway, it's always a bit nerve-wracking to replacing the PLL connectors off because
they could be brittle with age and you know, you could pull a wire out or something like that and
another, give yourself another headache, so I don't know, maybe see if I can gently grip them
with a pair of pliers, perhaps, on those pliers, I'm not sure if that's a good idea or not,
that one coming out, like this one out, good, F, yes, that's one.
Yeah, I wonder if I should maybe take a photograph, I've got a photograph, I should be okay,
I should maybe I'll just take a sneaky photograph because otherwise I might forget which plugs go
where, which is just in case, so I'll just pause this for a moment, I took two separate photographs
said to other plugs, there's six connectors in two banks, so three connectors on one side and
the right-hand side of the speaker as you look at the reader from the front and three connectors
on the front face of the, the face of the front basically, so I've got one removed, one of the F
connectors with the orange, black and red wires, it's like a bomb, like a bomb disposal film, you say,
don't cut the red wire, okay, so we don't break the flim and plug, right, so connector two,
oh, that came out very easily, it's got a green, green and white wire, red and white wire, red and
white and so orange and white, I'm not sure, that's the second plug, and in the last plug on
the right-hand side which has got a screened connect, screened wire and a pick tail, a pick tail,
basically you take a tapping of the screening around outside of the wire, put a heat sink over it
and then you have a tail off to the sides, that's why I got a pick tail, oh, that's off good, good,
so it's a screened connector, a screened cable, it's obviously got a screened outer
sheathen on the cable and you basically solder the solder out a wire to that,
it's screening and then take off to the side and pick what they call a pick tail,
at least so what, that's what I know it as, so with the connector, the socket's got numbers
and I think they might be do, yes they do actually, what do they say, just out of curiosity,
lights just awful here, I remember that I had actually a headband torch, put it on your head,
so that helps a bit, just hold it, so 48, 29 and 30, so that's the connector, numbers 48, 29 and 30,
okay, doesn't mean anything to me, but okay, I don't know, these front ones are going to be a bit,
a bit tighter, a bit more tricky to get off, so to be careful with that, I don't know if I can
get my pliers into those, oh that's not much room there at all, I wonder if I can,
one of us should maybe, oh I don't know, I bet if we can get in from the top,
don't know about that, no, I'm a bit nervous, I break something, there's not enough room,
because maybe if I lowered the front panel again, I'd prefer not to do that,
that's one alternative to remove the front panel, I don't know, can I shift the board more to
the back once I loosen it, I wonder, I'll tip it up on her, yeah maybe I can do it that way,
so I'll tie loosen the screws, that's not a job, but her I'm going to stop the screws from
following, say the radio, that's a good question, put along those pliers perhaps,
nothing's easy is it, okay, so I heard the screw clicking, so it's obviously loose,
pliers, I should be able to get a catch up with the pliers, nope,
I wonder if I can just just loosen them, I'm going to do it that way, I wonder,
yep that's that one loose, that's two loose, use of some movement,
I don't know, I'm not sure, I should be able to pick these screws out,
all right, I've got a light glass here with different glasses off,
and a headband touch, let's see if I can get over there with that,
a light, look at that, just a light, and
now I'm definitely going to drop this screw, I think we need to pause this and do this, but
without recording, I'm going to come back, because I ended up making a mess of this, so
I'll be back in a second, once I've got these screws out, okay, so I might as well
loosen the full four screws and tip the board up a bit so I can get better access to the
connectors on the front, I noticed actually removed one of the screws, I actually got one of these
cable clamp things, which are really hard, they look flexible, but I guess I'm guessing more and
more now that they're supposed to be like that, they're like, you bend them and they stay put
sort of things, you hold the wires in place, anyway, I think I can maybe just leave the screws
in place and lift the board once I've got the connectors out, I've got one of the connectors out,
so I can connect it out, that's good, and now the big main connector on the front,
that's going to be a bit tricky, oh no, easy, that one's the easiest one, goodness,
it's a great big connector, I thought it would take a lot of force to remove, but it hasn't,
so that's good, I can now, in theory, lift the speaker up, now I have done that,
here, now I can swivel it out to the side, the chapset, or I can remove the connections,
but obviously swivel it out to the side, I think,
hmmm, it's all the screws are in place, actually I think I'm going to remove these screws
because I don't want them to drop inside the radio, so that's one, yeah, that's two,
and then that's three, yeah, it's better, I feel a lot safer now that I've done that,
because I'm trying to fish them out there, radio would be a nightmare, that's toxic, I'll do the
move when I'm previously, yeah, well that's all four screws, so moved, goodness, right, so he said
that there's a silver box which holds, looks like the battery, actually I'll take a picture just
to show the speaker off to the side and in the box I'm talking about, okay, right, so it looks
like there are one, two, three, four, five, six, seven, and a sneaky eighth one,
which is going to be a bit tricky to get to,
hmmm, of course it would be wooden, I'll take out the easy seven, I suppose,
right, these should be quite straightforward, so one,
I get the feeling that this has not ever been replaced, there's battery, I notice that the
plastic, I don't know, a tie-rappy thing that to secure the cables, had been opened, so obviously
the, somebody has been into this area as well at some point doing something,
so that's two of these connectors, one on the board on the top,
and one at the side of the radio, beside this silver box thing, so obviously, I mean,
hardly surprising, good, it's a 19, I think something in the 86 video, I don't know what, I could
be wrong about that, but it's that era, so I had it opened once to do a repair, but I don't know,
the, I mean, I know the chamber bought it from, but what the history, well, he had it, I don't know,
maybe screws feel quite, quite secure, so I get the feeling these have never been removed,
one, two, three, four, okay, five, that has been particularly careful not to drop a screw inside
the radio, five, okay, put it out to the side, six, that's when you're going to be able to be
easy to get it, seven, it should be quite easy to get, easy-ish,
side to get more tricky now, interesting, when I get the top cover off, I'm going to do a measurement,
I'll check the battery voltage to see, suppose, any washers under these screws,
thankfully, because, you know, I just love to drop the washer first, trying to remove the screw,
can I get to, oh, a little bit of a cookie noise, I didn't like the sound of that,
ah, it's just, okay, now that's fine, I could just push the puller bar to the side slightly,
and get to this last screw, yeah, that's fine, I can get to that one, I think,
well, I can certainly loosen it, whether I can actually get it as another matter,
I'm going to drop it inside the radio moment of truth, last screw, okay, how the heck do I grab that?
Can I grab it with a pair of pliers, I wonder, wasn't too successful with that earlier,
moon pliers, oh yes, oh, good, so that's all, one, two, three, four, five, six, seven, eight,
a screw, maybe, way from edge of the table, right, so, I'm going to remove the speaker over a
little bit more, let's have a bit more room, all right, I can now tip this, lift this board out
the way, is it going to lift, oh yes, yeah, oh, hang on, there's more connectors,
I didn't mention those connectors, right, there's, there's one, two, three, four, five, six, there's,
there's actually some sneaky connectors at the back, can I get it out without removing that,
well, maybe, can to be fair, to be fair, come back, can I, let's just see, can I, here, maybe,
and I don't know, I'm not sure, I'm not sure about this at all,
oh yes, I can, it's quite right, you only need the six, there we go,
and that's it, tip over, oh yes, there is some corrosion, and actually, in fact, maybe even some
water, not water, acid, or condensation, on the top of the battery, so, I'm probably going to
just be removing this just in time before it wrecks the radio, wow, so I shall definitely take
a picture of that so you can all see the dangers of leaving these batteries in there, of course,
the thing is, I don't know, these are just EBA batteries, and it says 2032, so it's a standard
2032 button cell, modified to suit this application, and not even for this application, it doesn't
it doesn't quite fit properly, but good enough, anyway, I actually take a photograph of this,
hopefully these batteries are going to last a long time, these replacement ones, I'm not going
to leak, because it's always a danger, you put cheap cells, and then two, three years in line,
they leak, catastrophically, or whatever, I guess it's a risky take, anyway, hold me a second
and take a photograph of this, okay, so that battery definitely needs replaced, Kiroki,
that the battery, I can't tell if that's liquid on the top or not, but it kind of almost looks
like it is, you can see I see this kind of sweating almost on the liquid on the top terminal,
on the right hand side, but actually on the surface of the battery it almost looks like it's
there's liquid acid, perhaps, it doesn't quite show up in the photograph, but yeah, so that's
definitely something that needs to look to it, oh, I've just noticed there's two, there's two
connectors going into the main circuit board, and two, they have wires coming from them and in,
two connectors on the other end, but they don't go anywhere, they're not turned into anywhere,
so I don't know what that was used for, and there's a couple of brass pillars for mounting,
something like that, so I wonder if there's a an add-on board or something you could, you could,
you could, an option, there was lots of options you could buy, the way I'm making it,
someone you could, you could buy filters and various bits and pieces, and I also noticed that
there's a socket just above the battery, there's a, above the battery, there's a device and I see
possibly a pro or something on a socket, and above that there's another socket which is not
populated for some sort of IC, I wonder what that's all about, I don't know, maybe I'm going to do
a bit of investigating and see, I'm just checking I think, I don't think any damage is
recovered because of the battery, so I just got that in time. Okay, I think that's about it for
this episode, I don't think I'm much more to say, these were recorded in two sections, and I wasn't,
we're getting quite long, I wasn't sure how many episodes I was going to make out to the two
recordings, I think it's going to be either five or six, we'll see how it goes, if you want to find
out if it's ultimately successful or not, I only take cardio and musting, and if you want to contact
me or have any comments or whatever, you can contact me at MrX, at hpr at googlemail.com, that's MRX,
ATHPR, the at symbol googlemail.com, so until next time, thank you and goodbye.
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