Strange mods to old tube C.B. What are they??

[lemonmade]

I'm an old coot and have wanted a tube CB for as long as I can remember (I'm not certain why). I found a Courier 23 for sale cheap, and picked it up, hoping it would work, otherwise I still have room in my garage.

Anyway, I'm not really a radio genius, but I encountered a weird (to me) modification to this radio, that is confusing the heck out of me. The previous owner has installed a 10 position rotary switch, at the top left corner of the speaker grill. Looking inside the box, at the switch, there seem to be 7 crystals mounted to it. If the added rotary switch is set to position 8, or 9 or 10 which don't have a crystal mounted to them C.B. channels 1 thru 4 do not seem to show any reception (I haven't tried transmitting, since I don't have a suitable antenna), yet if you move the rotary switch from positions 1 thru 7, while the C.B. channel selector is set to 1, 2, 3, or 4, the static changes pitch, and the meter needle varied it's position. Of course, since no one seems to use C.B. anymore, I haven't actually heard anyone talk on it.

At first, I thought that it was some sort of mod to modernize it to 40 channels, but I'm starting to doubt that. Does anyone have any idea what purpose this mod was for? I appreciate any input. Thanks.

 

[mmckenna]

Sounds like someone added some additional channels to the radio. There should be some numbers on each of the crystals. If you an post those, we could probably help you figure out what they are.

 

[lemonmade]

Sounds like someone added some additional channels to the radio. There should be some numbers on each of the crystals. If you an post those, we could probably help you figure out what they are.

Well, just taking the back plate off doesn't give a clear enough view of the crystals to read their frequency. My knob removing skills seem to be lacking, keeping me from entirely removing the outer case to get a better view of the crystals.

If I can figure out how to remove the case without trashing the knobs, I'll get back to you with frequencies. Suggestions for safe knob removal are welcome.

FWIW, the radio also seems to have channel 22A added. I guess the previous owner was a pretty sophisticated user.

One more question, is the C.B. band so dead now a days that it is difficult to find any traffic at all? I've had channel 19 on for several hours, and not heard anything. I live about 4 miles of an interstate highway, and figured that at least a couple of truckers would still have a CB. Just for listening purposes, I'm just using a Sangean 32 foot, wind up S.W. antenna. That should work, right? Don't worry, I know better than to try transmitting without a real matched antenna. For the time being, I would be happy just to know if it worked. Thanks again.

 

[JayMojave]

Hello Lemonmade: A good Tech could map out what frequencies the radio has.

It sounds like you may not be on the right channel or frequency, or the radio just isn't receiving, Even with a mis matched antenna you should be hearing CH19 and a bunch of skip during the day.

Its hard to give advice on just what you gave us. Good luck!

Jay in the Mojave

 

[mmckenna]

Not sure, I tried a CB in my truck last year after not having one for 10+ years. I was driving down Interstate 5 in California and only heard two truckers the whole day. That was with a permanent mount Larsen NMO27 properly tuned. Other than the noisemakers from the Southeast, there weren't any users that I could hear.

 

[LtDoc]

It may help to shorten that 32 foot antenna to something like 9 feet or so. Won't be a good transmitting antenna but it will at least get 'closer' to right.
I'm afraid the traffic on the CB band is dependent on where you are, most places are not as active as they used to be. Other places have lots of traffic.
As for those extra crystals, the previous owner added them to get more channels. Which channels is anyone's guess until you find out what they were 'cut' for.
Good luck.
- 'Doc

 

[atech]

Boy I have not seen a courier 23 in a few years. I worked on a few.. Ch 22 A was actually in the old 23 channel CB days. In between ch 22 & 23.. Back in the early 70`s they tried to say it was a business channel? The mods your are looking at add channels to the radio.. Originally 23 channels.. The channel selector channels 1 to 4 go with the mod switch.. As you go channels 1 you select another channel via the mod switch.. This will eventually give you 40 channels.. You will find it adds up from channel 23 to 40 using the mod switch and extra crystals.. Do NOT transmit without a proper antenna on that radio.. They don`t like it! Set the Mod switch to channel (1) or some off an off position. Then use the normal channel switch and try channel 19 for your truckers again.. Also if you have a Dummy Load and freq counter? You could find those channels and freqs easy.. Hope this helps you out! Look for CB mods or I suggest ARTSCI Publications for a mod book.. That would explain some of this better. Also lots of google info on that radio.. 73`sss

 

[lemonmade]

Boy I have not seen a courier 23 in a few years. I worked on a few.. Ch 22 A was actually in the old 23 channel CB days. In between ch 22 & 23.. Back in the early 70`s they tried to say it was a business channel? The mods your are looking at add channels to the radio.. Originally 23 channels.. The channel selector channels 1 to 4 go with the mod switch.. As you go channels 1 you select another channel via the mod switch.. This will eventually give you 40 channels.. You will find it adds up from channel 23 to 40 using the mod switch and extra crystals.. Do NOT transmit without a proper antenna on that radio.. They don`t like it! Set the Mod switch to channel (1) or some off an off position. Then use the normal channel switch and try channel 19 for your truckers again.. Also if you have a Dummy Load and freq counter? You could find those channels and freqs easy.. Hope this helps you out! Look for CB mods or I suggest ARTSCI Publications for a mod book.. That would explain some of this better. Also lots of google info on that radio.. 73`sss

Thanks all of you guys for the input. I know it's kind of hard to guess what's going on when I can't even get the case open to read the frequencies on the crystals.

A special thanks to atech. It's interesting to know how creative the old school cber's used to be. No, i don't have a dummy load, or frequency counter, but I do know better to try to transmit w/o a matched antenna. I'm not looking to put a lot of money into it, but I'll probably check ebay for a used frequency counter, just to benefit my curiosity. I kind of hope that it works, but it shined up nicely and looks cool just sitting in the den with the Turner 2+ mic (which has a Duracell battery with an expiration date of 2000 on it ). Anyway, without a frequency counter, or another CB, I might never figure out if it works.

Just out of curiosity, are tubes still made anywhere? What's an average tube cost (i know it will vary all over depending on type.)? How much does a typical crystal cost? All the tubes seem to light up, but I know that can be deceptive.

Any ideas for a particularly cheap and easy to make 11 meter antenna, for testing purposes?

If there were any radio shops still in my area, it would probably be cheaper to just pay a tech to tell me if it's in working condition, but I guess where's the fun in that?