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Wanted/ISO: 23 to 40 channel conversion channel selector

ExitThirteen

ExitThirteen

Grumpy and Cranky
Apr 18, 2008
1,968
1,691
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Cornpatch of Iowa
Hey guys! Long shot request, but I'm after something that's going to be a bit of a rarity.

I'm looking for a channel selector switch out of an old 40 channel CRYSTAL CB radio, or a channel selector switch that converts a 23 channel crystal radio into a 40 channel. I have an old Pace 1000B Sidetalk base that has all the hardware and crystals for the 40 channels, but the selector switch is only a 23 channel. I had a 1000B Sidetalk that was a parts radio that had a legitimate 40 channel selector switch in it that was setup for crystals, but the radio got thrown away. I'd LOVE to get this old Pace radio going again, as it's in great shape and has had a full recap done, plus a full alignment. Please let me know if you may have something that will work. Thank you!


~Cheers~
 

Now here's a murky and largely-forgotten corner of CB history.

40-channel radios with 16 or 30 or more crystals.

The only one I ever saw that was ever type accepted to sell legally was the Tram D201A.

Might have been others, but I missed them.

The CB market fell into chaos when the FCC aonnounced the 40-channel expansion. Nobody would by a 23-channel radio.

Nobody. The manufacturers said "No big deal, we'll just sell you the upgraded channel selector".

But two problems intervened. The FCC took at least half a year to unveil the new technical performance requirements for "type acceptance", the name they used for official approval to sell a radio in the USA.

Round about the time those expanded crystal selectors began to pop up the new, and much-tighter performance limits for a legal 40-channel radio were revealed. There were now limits on what kind and how much "spurious" RF could leak out the the radio.

On receive, and transmit.

Both.

The 23-channel rules were a LOT looser. The shielding and filtering needed to meet these limits could never be retrofitted to a 23-channel radio.

Never.

Second problem, the price of crystals was rising. And the cost of a PLL chip to carve up one or two crystals into 40 channels got cheap.

As a result, the time it took to redesign new 40-channel models, get them approved, built and into the sales pipeline made a crystal synthesizer obsolete.

There had been a few PLL 23-channel radios, but ALL the 40-channel models used the new technology.

All but a handful.

An outfit I had never heard of made "crystal selector upgrade" switches. Called themselves "Beta-Com". This was never legal, but I suspect they were built before those long-delayed type-acceptance limits got published.

Only stumbled across these on Ebay recently.

Here's one meant to add the needed 4 extra crystals to a Standard Horizon 29 23-channel mobile radio.

https://www.ebay.com/itm/Standard-G...e=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649

No crystals, just the selector and four crystal sockets.

But I think this is what you meant.

73
 
That selector you listed the link for should work. I'll figure out the logic for the wiring and can wire it in fine. I appreciate you digging me up the link! I wasn't typing in the correct words in the search box, it seems.

The parts Pace 1000B Sidetalk base I had was a legitimate 40 channel crystal SSB radio. Had all the crystals plus a 40 channel selector, I believe it was mfg'd in Jan./Feb. 1977. I also had a same era Midland 79-892 that was also 40 channels with full crystals.

This is the current radio I have. Has all the crystals and hardware installed for 40 channels, but only has a 23 channel selector switch.

[photo=medium]4977[/photo]


~Cheers~
 
Last edited:
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ExitThirteen said:
That selector you listed the link for should work. I'll figure out the logic for the wiring and can wire it in fine. I appreciate you digging me up the link! I wasn't typing in the correct words in the search box, it seems.

The parts Pace 1000B Sidetalk base I had was a legitimate 40 channel crystal SSB radio. Had all the crystals plus a 40 channel selector, I believe it was mfg'd in Jan./Feb. 1977. I also had a same era Midland 79-892 that was also 40 channels with full crystals.

This is the current radio I have. Has all the crystals and hardware installed for 40 channels, but only has a 23 channel selector switch.

[photo=medium]4977[/photo]


~Cheers~
Click to expand...

Might be time to revisit Motorola's AN-756... attached :)

An attempt to get someone else to do my dirty work :)
https://www.digikey.com/product-det...p06GxrexH7HqTEYeklp_WdEdFUZM9MrsaAvppEALw_wcB
And the now seemingly everywhere LTC-1799
http://cds.linear.com/docs/en/datasheet/1799fd.pdf
And floatin on a boat ...
https://www.ebay.com/itm/1KHz-to-33MHz-Adjustable-Oscillator-Module-LTC1799-/400292172818

So here is my twisted thinking. Either an oscillator per (which seems a waste) , or a resistance per frequency or the Motorola switched oscillator or ask Nomad about a modified PAL VFO .

Yeah, I have a "keep them clean" desire also. One of the front feet on a D201 I built was a rotary switch knob :)
On another it was magnetic reed switches and refrigerator magnets . Last but not least is I really want to try one of the (how the hell can they sell them so cheap) Chinese DDS's. My concern is the wonderful phase noise free crystal and or tube radio would be overcome by the increase in noise floor. Then the inevitable drift of any VFO/DDS.

Never confuse me with being "conventional" .
 

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Back in the day, The fine folks at Selman Enterprises sold the Beta-Com 40 Channel adapters. All of the Beta-Com info was published in Secret CB Volume 2, pages 56 - 87.
Here's a link to the info.

http://www.cbtricks.com/pub/secret_cb/index.htm

You can compare the truth table on the Beta-Com Model SWM-53 (the one that was spec'd for the Pace 1000B) and make a switch using the ATMEL tiny13A microcontroller and control it with a 40 channel switch of your choice. Or ... you could try to find a Beta-com SWM 53 module. Good luck on that.
 
A few years ago when contemplating getting back in to CB I acquired an old Pace 1000B Sidetalk base that had all the hardware and crystals for the 40 channels and a 40 channel selector switch. Rx was good but TX wasn't so I took it to a CB repair shop located at a Sapp Bros. truck stop near Cheyenne, Wy operated by a well known tech that shall remain nameless. He told me it wasn't worth the time or money to repair it. After much bragadocious rambling and attempts to sell me a newer "Modded and ready to go" radio I just quit listening, thanked for his time and left. Didn't have much invested and nobody else seemed to want it so in the trash it went. Sure wish I had kept it.

That tech moved on about a month later. Heard he went to another truck stop further East.
 
LC, I ordered that same one you linked, so it's on its way to me now.

Rok55, I love the old vintage sets like the Pace 1000B. They have great sounding audio, and the build quality is great! I'll probably use this set all the time once I get the channel selector in!

~Cheers~
 
Glad you got it!

I actually came across it by accident looking through one particular seller's items. They had bought out an old cb shop.

Hope you'll post pics of your project when it's done.
LC
 
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ExitThirteen said:
LC, I ordered that same one you linked, so it's on its way to me now.

Rok55, I love the old vintage sets like the Pace 1000B. They have great sounding audio, and the build quality is great! I'll probably use this set all the time once I get the channel selector in!

~Cheers~
Click to expand...
Just a note on the switch, Remember it is still a switch that is literally 40 yrs old! So take precautions before giving it a spin and use some really good cleaner+lube before you do I don't know if the switch has already been turned but it's a safe bet that is sat for most of its 40 yrs unturned. And yes it's not a simple matter to the cleaner in one of these and maybe you won't have to.
 
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ExitThirteen said:
Hey guys! Long shot request, but I'm after something that's going to be a bit of a rarity.

I'm looking for a channel selector switch out of an old 40 channel CRYSTAL CB radio, or a channel selector switch that converts a 23 channel crystal radio into a 40 channel. I have an old Pace 1000B Sidetalk base that has all the hardware and crystals for the 40 channels, but the selector switch is only a 23 channel. I had a 1000B Sidetalk that was a parts radio that had a legitimate 40 channel selector switch in it that was setup for crystals, but the radio got thrown away. I'd LOVE to get this old Pace radio going again, as it's in great shape and has had a full recap done, plus a full alignment. Please let me know if you may have something that will work. Thank you!


~Cheers~
Click to expand...
I have the data com swtchyou a looking for have a lot of old radio stuff 40 year in radio business retiring phone 660 886 3233 live in missouri
 
A word about the so called Horizon 29 switch that guy was selling. The Standard Horizon 29 had a 23 and 40ch version, but both also utilized the same PLL. I’m not aware of either version of the Horizon 29 utilizing a crystal matrix board. I have the Horizon 29 23ch version. The extra channels (at least most of them) were obtained via the address pins on the PLL with a toggle switch. Who knows what radio that switch belongs on...
 

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