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Whoa! That's odd. The "silver bridge" is a test jumper. Carries current from the modulator circuit out of the inboard-most fork, and out to the final transistor through the center one, and to the driver transistor out the left-most one. Pulling it out should kill any and all transmit power. If...

So here's a detail that reveals Carl has a clue. The small brown lump against the left side of the relay is a silver-mica cap. One side grounded, the other side connected to the relay's receive (standby) side. When an amplifier is put in line with a radio, the radio's SWR reading should not...

Craig's CB line was a fairly-big deal until 40 channels. They got flushed down the same drain as 95 percent of the other brands that had sold 23-channel CBs. They were mortgaged to the hilt to fill the pipeline with 23-channel models. When the FCC announced the expansion, you couldn't give a...

I gave up on making frequency counters tap into those radios for a stable reading. If you have a ham transceiver with its frequency reasonably calibrated, tune in the frequency you want to set, like 10.6975. But set the radio to LSB and tune to 1kHz above, 10.6985. There's an app out there that...

That model uses a class-A audio amplifier. Not so different from the 1960s Delco AM car radios that had the fat doorknob transistor on the rear. It's a current hog. Draws almost as much power supply current on receive as some radios will transmitting a dead carrier. YMMV. 73

Rock on! Gotta love it when a plan comes together. I usually recommend turning the control to full power and setting the carrier with the radio's carrier control. The pot becomes vulnerable to burnout only when it's turned down, as a general rule. 73

It wasn't new when you got it 30 years back. Should date to the mid-1980s IIRC. If you just don't hear that "click" from the relay when you key the radio, odds are that the filter capacitor for the keying circuit has failed. This drops the voltage feeding the relay too low for it to activate...

The member eastside was last here in 2017. 73

Uh, "tie in"? As in breaking the power feed to the driver transistor to insert a NPN transistor for carrier control? Don't have a picture of the circuit board handy. I don't think there is a handy wire jumper that you can remove like the Cobra 29LTD radios. I'll see if I can find Sams CB121...

D&A used this ruse after 1979 when the rules got tightened. What was old is new again. 73

They also serve who only watch and wait. Thank you vets and your families, too. 73

With the stock 11.325 crystal, jiggering the PLL binary inputs makes the top frequency is 28.045. To reach 28.5, that's 455 KHz higher than 28.045. Since the PLL downmix crystal is multiplied times three, the crystal needs to be one-third that much, just more than 150 kHz higher. The 11.475...

Last server supply I saw sounded like a jet airliner running up for takeoff. 73

Rock on! Gotta love it when a plan comes together. 73

It's always easier to ask for forgiveness than permission. 73

The point in asking about receiver performance is that if both transmit and receive are weak, it's being caused by a resource that both are using. This points to the VCO that controls the receiver and transmit frequency. I don't have the schematic handy, but I think the VCO output is L20. If it...

Is the receiver sensitivity up to snuff? If not, maybe there's a hint. And it hears weak signals like it should, this is just a red herring. 73

You could click on this link ->>> https://www.icamanufacturing.com They sell this part. Or this link https://www.rfparts.com Both of them are legitimate sources and safe to buy from. The cheap sellers on fleabay may sell you a fake, might not. 73

As Indiana Jones said: "It's not just the years, it's the miles, too". Heat exposure and operating hours affect service life. A new-in-box radio that's 40 years old may not have one bad electrolytic. A radio that was powered 24/7 for 20 years will be more likely to have failed caps in it. A...

A peak 1.5 turns below the rim is an actual resonant peak, so that's not the cause of the weak power. Have you pulled the bias-test jumper loose and inserted a current meter to set the driver and final idle current on sideband transmit with no audio? Might be relevant. 73