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Darn shame the people who buy linears don't. 73

Wow! Not a common fault. Leads me to wonder if the problem is at the downhill end of the radio, something causing the AGC voltage to jump up? Or is there a sneaky fault with the transmit/receive switching? A meter, or better yet a 'scope on the two switched-voltage jumper wires J26 and J27...

I would check the two fattest wires coming out of the power transformer, and follow them to the power socket. If a crummy solder connection has caused the problem, you'll see it there. And if you do a continuity check across those two wires with the power cord unplugged, a bad transformer...

Haven't seen anyone counterfeit a NTE part yet. At least it's probably old enough to be an original-production american-brand part. Not sure it matters so much which original part so long as it works in an amplifier. 73

Here's the schematic that goes with that service manual. 73

The Body Bag Pride DX300 is for sale. The guy who had first refusal didn't come up with the funds. So now it's up for grabs. It's fully functional except for the receiver preamp and the SSB switch. If you want to use it for sideband, there's a RCA jack on the back to "hard key" the amplifier...

Okay, so what's the callout number of the cap in question? I see some point zero one 50-Volt caps in the list. If that's the one in question, a 3kv part won't be that much larger. Not about to criticize dyslexic. 73

A croaked, er, 'cracked' 6BA6 will do it. Gotta love a simple fix. 73

About that S-meter. Really does provide a dividing line to begin troubleshooting. 73

Fine print says only if the heat sink is held somehow to 25 degrees C. Graph shows about half that dissipation with 600 square cm of heat sink with the ambient temp at 25 C. Still a rough tough-rated part if you can find it. 73

Ah, do we have the right capacitance units here? Microfarads? Or picofarads? A 100 uf 3kv capacitor should be the size of a gallon gasoline can. But a 100pf 3kV disc cap won't be much bigger than a nickel or a quarter. And a 100pf 50v ceramic disc may be a quarter inch diameter, maybe...

If so, the S-meter will not show much if any movement. And if the S-meter is still showing channel chatter, you have an audio problem not a RF problem. Since the DC power input branches off to the speaker-amp chip before the voltage gets dropped down for sensitive receiver circuits, the audio...

The 139XLR is a sideband radio. The 89XLR is AM only. The PLL arithmetic is nearly always different from AM to a SSB radio. For Uniden, anyway. That's who built those two radios. And that's what has to match from one radio to the next to swap channel selectors. 73

More than one way to skin a cat. 73

It's a Fujitsu brand type FBR221ND012. Not sure what the "-20" indicates, but Fujitsu routinely left off the prefix letters "FBR" from the type number. Looked online for a spec sheet, but it's been too long since it was discontinued, looks like. Oddly enough the single-pole version of this...

Pretty sure I have the schemo on file at work, but not at home. I'm not cloud-friendly yet. I'll check back in next time I'm there. 73

Both radios share the same main pc board, but the 142 is a bare-bones radio. The D300 has some wocka-wocka features the 142 lacks. Which radio are you trying to document? The Cobra or the D300? 73

A resistance check of the meter would reveal if the coil inside it has failed and become an open circuit. Would be a bummer, but that failure would show this symptom. The meter's negative side has a diode connected to it. Not a likely part to fail, but testing it would tell you for sure. If...

Ahh, multiple postings of the same message is considered poor manners on most forums. A single thread for a single subject is easier to keep track of. But hey, welcome to WWDX. There are some suggestions about where to start in the PM reply and following your post in the "General CB" section. 73

Ain't none. And no schematic diagram. All of them we've seen so far don't need alignment. Starting point for alignment instructions would be the schematic IMHO. Not sure who you would have to blackmail to get a hold of that. 73