Tube CB repair?

ChopperChas

ChopperChas

Super Member
I have a Heathkit GW-10 CB base station. All sweet, sweet tubes on the inside. It doesn't really transmit or receive, but powers up. Actually not sure if it doesn't receive, or if there's simply no CB traffic anymore. (I am right next to a major interstate though)

Anywhere I can repair this beast? It'd be nice to have in case of a nuclear holocaust that EMP-fries everything else. :)

Charles.
 
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Likely it has worn out and failed capacitors just like any old tube eqpt. I assume you're not into doing it yourself? If not, where are you located? That might help us suggest some potential technicians.
 
Well besides recaping it , you need an antenna , to receive on it . Also make sure there are TX and RX crystals in it , tube CB's where before PLL circuits .
 
I used my father's (early 1960s) vacuum tube RCA Mark VIII CB back in the 1970s... folks commented on how good it sounded on the air... and it did sound good. No D201 nor Golden Eagle, but nice clean warm sounding AM output.

Antenna's really important for 11 meter (CB)... re: the xtl (crystal) comment; does that particular CB also have a tunaeble receiver? Many did (the aforementioned RCA included).
 
It has both crystals and a variable tuner. Neither appears to work with a hand-held CB I have. Although I can't pick up anything on the hand held CB either, so who knows if any of this works.

Antenna is just a wire stuck into the RCA jack for the antenna, but you'd think it would work in the same room as the hand-held at least.

Charles.
 
HEATHKIT%20CB%20MODEL%20GW-10.jpg
 
Cute little transceiver.

One caution (and you probably know this) - do NOT try to transmit with that base station without a proper antenna installed. It can even be a small "coil loaded" back-of-set antenna, but it must be reasonably well impedance matched to the transmitter of the CB, else one risks damage to the output stage of the CB.
 
An SWR meter is helpful to see how well matched the antenna is to the transmitter - the bottom line is one needs a 52-ohm antenna (or dummy) load. These used to be readily available - I am sure it's no problem to come by CB antennae on teh webs.

Here are some examples - this is just a Google result; I have no experience at all with this vendor nor any of the antennae I just saw on the page!
http://www.rightchannelradios.com/cb-antennas/shop-by-type/base-station-cb-antennas.html
 
Most any ham radio operator could test it with a dummy load for transmit. CB radio is a great wasteland of idiots, and really only used today by truckers and lowlifes for very short distance communication. Functioning, it might be worth $25. Don't waste your time.
 
I think it's damn cool, and I would definitely fix it up. On something like this, you begin by rebuilding the power supply by replacing the filter caps and power resistors. Then you replace any and all coupling caps. Then you would re-flow every solder joint with a little flux. Finally you would test all the tubes and replace any that are bad or weak. Not as big of a job as it sounds if you have the stuff to do it with. I think it would be tons of fun talking to the truckers on the highway. A lot of them have probably never heard a tubed CB.
 
I vote Jay to fix it

How about it Jay? Fix it.

I am a ex-ham. I am renewing my general class license again after 10 years. I always had a CB in the shack. I like the Robyn T-240 tube type CB.
 
The variable tuner on that radio is just for receive. The transmit frequencies of all CB radios are required to be crystal controlled.

The crystals that control the transmit frequency for that radio are plug in types, so they could be changed by the owner.

Check to see if there are any installed.

Also if you want to use a piece of wire for an antenna, make it about 9 feet long.

That will supply a reasonable load for the transmitter and might enable you to hear some signals. With the radio in the tunable mode, tune around channel 19, the dial may not be exactly accurate.

The output indicator is a neon lamp connected to the plate of the final RF power amplifier tube, IIRC a 6AU6 tube.

If it lights when you try to transmit, and flickers a little bit when you talk into the microphone, the transmitter section is working.

Remember the tunable dial only controls the receive channels. You will have to figure out what channels are controlled by the crystals and it may just be a single channel transmit.

Edit: it looks like it may have 3 crystal controlled transmit channels and one crystal controlled receive channel according the the information that I have.
 
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sony6060 said:
How about it Jay? Fix it.

I am a ex-ham. I am renewing my general class license again after 10 years. I always had a CB in the shack. I like the Robyn T-240 tube type CB.
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Congratulations on rejoining the the ranks of us amateur radio operators!
 
I would do it, but I have a huge project going right now that's way past due. Damn job keeps getting in the way of my hobbies too.:thumbsdn:
 
:scratch2:once (long time ago) I inherited 12 channel globemaster That one worked. Also a knight which broadcast a carrier but no sound. (It pissed off local cbers thinking I was just some idiot chucking carriers. I think its cool. I also think my wife would leave me if I started bringing home tube cbs to fix and play with. She doesn't seem to understand why I have 6 amplifiers and almost that many sets of speakers (come to think of it I'm not sure I do)
 
I think that one is a single crystal transmitter with the fully variable receiver. They're rather less than practical to use these days, though if you can get your hands on a VFO to replace the transmit crystal, it becomes a lot more useful. That isn't technically legal though, fair warning. The band has been 40 channels since the late 1970s, and a lot of older rigs were either mated to a VFO, sometimes called a "slider" or wired to a "rock box" which let you switch in different crystals for more channels.

Its probably not all that involved to repair. I've personally overhauled much more complicated rigs. Really, CB radios aren't all that involved. The reciever is not much different than any superhet AM radio made. Those old crystal transmitters aren't very complex either, especially the ones that don't have the multi-crystal mixing matrix arrangement. When you get into single sideband rigs, it gets more complicated. I have a fully crystal controlled 40 channel Tram, and that thing is a real mess to work on. Alignment on it takes quite a long time when you have to do 30 some crystals in order. Its extra fun when some have floated, and you have to fake the alignment by changing out the padder caps to get around having to buy $100 worth of crystals.
 
Here ya go

gadget73 said:
I think that one is a single crystal transmitter with the fully variable receiver. They're rather less than practical to use these days, though if you can get your hands on a VFO to replace the transmit crystal, it becomes a lot more useful. That isn't technically legal though, fair warning. The band has been 40 channels since the late 1970s, and a lot of older rigs were either mated to a VFO, sometimes called a "slider" or wired to a "rock box" which let you switch in different crystals for more channels.

Its probably not all that involved to repair. I've personally overhauled much more complicated rigs. Really, CB radios aren't all that involved. The reciever is not much different than any superhet AM radio made. Those old crystal transmitters aren't very complex either, especially the ones that don't have the multi-crystal mixing matrix arrangement. When you get into single sideband rigs, it gets more complicated. I have a fully crystal controlled 40 channel Tram, and that thing is a real mess to work on. Alignment on it takes quite a long time when you have to do 30 some crystals in order. Its extra fun when some have floated, and you have to fake the alignment by changing out the padder caps to get around having to buy $100 worth of crystals.
Click to expand...

You are all set up to bring that classic Heathkit back to life. :thmbsp:
 
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