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Finishing a QRP Guys Para40Set

Salvaging old CB’s for QRP Parts: Part 1

About three years ago, I stopped at a garage sale on the way to a friends home. It turned out to be an estate sale full of goodies for a guy like me, always looking for things that can be used or repurposed. I spotted a red bin with a bunch of cables and wires in it, and when I got to the bin, my heart skipped a beat! In it were at least a couple of cables with PL-259 ends, and 3 or 4 old CB radios! Now, I’m not into CB- I haven’t been since the mid 1990s’- but when I see any sort of radio equipment, I get excited to see if I can use it for QRP radio in some way, shape, or form.

I asked the man who was running the sale “How much for the red bin of radio stuff?” “Five bucks?”he responded. “How about three?” “Sure!” and that was that. For $3 I had obtained all this old radio junk. Now what?

I honestly didn’t expect much from it, but looking close I could see several high quality 1970’s vintage CB’s that looked to be in great shape. When I got home, I powered them all up and one of them even worked when I tried talking to a friend a few miles away in his logging truck.

But again, I don’t need CB’s. I want ham radio stuff. Are these CB’s any good for ham radio? Perhaps they could be converted to 10M, but these are all AM rigs, no SSB. So not worth it. There’s only one thing left to do, then:

Tear it apart!

I’ve been taking things apart since I was a few months old. Legend has it that I more than once disassembled my own crib! I still love tearing things apart but these days I try to focus on re-using them for other purposes. I’ve shown this before here on This Blog where I took an old radio and converted it into a 20m/40m direct conversion receiver: https://miscdotgeek.com/panasonic-am-fm-clock-radio-teardown/

I’m hoping I can make good use of this CB, too. To make sure I get the most out of it possible, I need:

A Method

When tearing something down, there are a few basic rules that I follow.

  1. Disassemble in a logical order
  2. Don’t break anything out of impatience
  3. Be patient (see #2)
  4. Save all the parts
  5. Look for value in unexpected areas
  6. Respect quality

These have served me well overall and are also a way for me to remind myself not to destroy things like I used to when I was young.

I was initially going to do this as a video series, but my video production quality and abilities leave a lot to be desired. Instead this will be a consideration of the radio after it’s been torn down. The next teardown in this series will be more of a step-by-step of the teardown.

Examining the Radio

As you can see from this advertisement to the left, this radio is from the 1970’s. In fact, this ad is from a 1976 Field and Stream magazine where its half page advertisement is sandwiched between pages filled with advertisements for the 1976 Ford LTD, Cigarettes, and Honda 90’s. It really was a much different time. I was born around the same time, and I remember the tail end of the 70’s and the early 80’s for being a much simpler, easy going time. Of course, my biggest concern at the time was watching cartoons, so I might be biased in that.

I could not find anything that says how much this radio cost when it was new, but all indications point to it being between $50-75 back then, which is about $225-$340 according to https://www.usinflationcalculator.com/. That’s a nice chunk of change!

The radio is also marked “Made in Japan” which at the time especially was a sign of high quality.

The Pace CB 145 was torn down easily. First removing the case top and bottom, then cutting out a mess of wires, and finally dismounting the main PCB. The PCB is single sided, and there were dozens of point to point wires connecting various parts of the circuits. Some of the gems in this CB include a double potentiometer with a built in on/off switch (used for Volume and RF gain as well as on/off), the 23 channel rotary switch, and the rotary switch to select CB, WX1, and WX2. This CB has a built in weather receiver that could be selected. A neat feature that even now is valuable. The switches can be seen below along with a 3A 12V fuse and fuse holder that was wired into the radio.

In the next picture, see how the chassis is laid out. It’s shown upside down, but if I re-use this for another radio, this will be right side up instead. The rubber grommets up front are for miniature light bulbs. You can see the chassis mount SO-239 in the rear corner too, and on the sides, the mounting for the PCB. It would be easy to use the PCB as a template to cut out a piece of lite ply to make a board for mounting our own radio.

Next we can see a lot of Toko style inductors, numerous other inductors, transistors, and capacitors. Whether or not those capacitors can still be used I don’t know. I do think it would be fun to build a small radio just out of the parts contained on this board! Certainly the electrolytic capacitors are no good, but there are a lot of fine things that could be reused. Inductors are just coiled up wire, and I can’t see those going bad over time- at least not in the fine condition these are in.

The crystals used to mix frequencies up for 26-27mhz are switched manually by the 23 channel selector, and you can see all the wires up front. None of the crystals are in the amateur bands, but that doesn’t mean they might not be useful in the future. I have a project idea that may make use of them.

One beautiful thing about the Internet is that schematics are often available for such radios, and I’ll be able to use this to identify all of the parts!

In Conclusion

Taking apart this radio was a lot of fun, and for me, a trip back in time just a little bit. Are there parts in here that can be used for QRP radio projects? Absolutely! Even the 4 pin Mic connector on the front panel is re-usable. Fuse holders, wire loom clips, the case, inductors, and various capacitors can all likely be salvaged. The knobs are all beautiful and in good shape, and even some of the potentiometers and switches might be usable.

Keep an eye out on the blog for the next tear down coming in about a weeks time, and let me know what you think about the re-usability of these parts in the comments below. Thanks for reading and commenting!

Update: Part 2 has been published: https://miscdotgeek.com/salvaging-old-cbs-for-qrp-parts-part-2/

6 comments

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    • AC7LX on April 25, 2020 at 2:54 PM

    Excellent Topic!

    • AC7LX on April 25, 2020 at 2:57 PM

    Don’t forget that these older radios typically contain several, impossible to source, genuine germanium diodes such as 1N34 and 1N60 types.

    1. Excellent information, thanks! Any thoughts on the inductors?

  1. That’s what I need to find. I used to tech CB’s back in the 1970’s and had a ton of that “junk”. Got rid of all of it after several moves. I was looking for an analog signal meter for my BitX40 and wished I still had all the stuff…

    1. Yes, this is one of the things I am keeping out of these CB’s: The meters! I’ll be doing a post at the end of this series where I’ll highlight the best parts that I could keep.

    • Michael Black on April 25, 2020 at 5:23 PM

    The IF filter and the RF output transistors are likely the most valuable parts. The others aren’t really special unless you are just starting to collect parts for the junk box. Just about any electronic device will offer up some sort of switches, power supply components, general purpose transistors and resistors and capacitors.

    It pays to watch for some things bevause “special” parts are more likely. So transistor radios of some sort will generally (if old enough) have variable capacitors. Cordless phones (and baby monitors) will generally offer up complete FM IF strips for narrow deviation. And many (if “old” enough), use an IC that includes a balanced mixer. Suddenly I can’t remember the common Motorola part. One can often use the detector section as a balanced mixer too. MC3362.

    There was a time when I was finding $5 clunky cellphones, lots of useful parts there and cleaning mplete narrow FM IF strios, striker metimes on their own boards. But those are long in the past.

    Consumer radios often have ceramic filters at 10.7MHz (wide) and 455KHz (narrow, though that varies, CB sets and shortwave receivers wouid have narrower filters and maybe better skirts). SSB CB sets of course have better filters, though after hoping for many years I found one for $5, but it’s a wide SSB filter.

    Tv sets used to have tuner modules, low power RF transistors and coils. Though eventually varactor tuned, though small values. (Digitally tuned am/fm radios likewise use varactors). More recent dtv sets are less obvious, and more integrated.

    Satellite receivers and cable converters also had tuner modules, easy to extract and sometimes scondary use. VCRs too.

    Consumer electronics often offered power transformers, though they night provide odd voltages and often low current. Them later replaced by switching supplies, often useful in themselves (and sometimes on boards by themselves).

    Inkjet printers, often scrapped, may have higher voltage power transistors, thiugh maybe not useful at RF.

    I used to carry some tools around to extract key components from electronic scrap on the sidewalk, though I see less of it in recent years.

    Sometimes it’s better to keep things intact until you need them. How parts are used can be defined by the equioment, and associated parts maybe the values you need (or just show how to use the main parts). Detach tyem now and associated parts or use may get lost. Some things you will be duplicating anyway, so just extract the whole section.

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