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yes, the FCC is not a law enforcement agency. I had them come to my house with a county sheriff deputy, back in 1993 or so. After I refused the FCC guy with a "little badge" entry into my house, he told the sheriff there is nothing they could do, and they took off. Then I got letters in the...

I was all over inside one of these radios last year. it was worked on by a few. it had over 10 amps current when keyed up in SSB, no audio in, so no RF out, and got hot. the bias adjustments all messed up, on the main board, and the external amplifier. IRF520s were changed, and I believe...

and yes, the 2 watt resistor needed at the input circuit if a few watts of input power, if it is a RF power amp. that was a big hint.

OK, thanks, AudioShock. I got the first unit, got the diagram on CB Tricks. I told the guy that gave it to me that it says it is a "Receive Boost Amplifier" and he said no, that they are a TX AMP. a "little modulator" so I took another look at the diagram, and figured it out quicky...

there is a 75 ohm 2 watt resistor on the input coil circuit. would not need a 2 watt there

but NomadRadio, when these first came out, were they used as a receive pre-amp? ? and people saw that with a few changes it can be made into a transmit linear. but not much power from a 6BQ5. there are two of these in my area and the guys refer to them as "little modulators"

yes, the guy down the road brought me a JB-12 "Receive Boost Amplifier" (cute, ha ha) to repair a few months ago. as Nomad said, the negative bias. pull that 6BQ5 out, don't let it get red. no need for it to be in the circuit at this point. power up and measure around negative 45 volts...

on your VR14. maybe you can get some rubbing alcohol inside the part... turn it back and forth to clean. maybe remove it from the board. a few days ago, I had a Marshall transistor guitar amp. no audio output, due to both the volume and gain pots being dirty. I removed them off the...

yes, I was just looking at replys here.. cool, you found it... stuff did not make sense. now it does. R14 adjusts the carrier level for AM/FM.

let's start from scratch. put the radio in LSB, mic gain all the way down (off, no RF to IRF520s) key up (TX). measure the voltage at all the IRF520 gates. let us know. should be around 3.7 V. but anyways, do this..... Do the bias adjust thing. just to make sure. remove the...

here we go! correct diagram, and pix. Too hot outside here in southern Louisiana for me to go outside. I got nothing better to do! but drink ice tea, cold beer, and work on guitar amplifiers and radios.

the zener diodes D112/D88/89 will keep the bias voltage from going over 5.6 V. And that would be way to high anyways. Usually it is around 3.7 V, but this must be adjusted for current through each IRF520. hopefully you are measuring in the correct spot. the gate lead spot is to the far left...

but maybe not if VR17 is controlling things OK in SSB.

So have you got this radio going yet? I would check out transistor Q55 that drives the modulation transistor Q54. it may be a tiny surface mount transistor.

ooooh! just took another look at some pix and the schematic again, on CB Tricks. just noticed there is no "mirror board" "shorting board" on the schematic or the picture. This would make it a little more difficult for some, to set the bias on the IRF520s. somebody messed it up. I bet...

I used NTE235/236 many years ago. they worked. Walked into a Fry's Electronics store in and picked them up. but now these NTE's are hard to find. NTE Parts Direct says they have some. ? ? ? DO NOT BUY OFF eBAY / AMAZON 2SC1969 or MRF's or anything like that. all fake.

if them IRF520s are still out of the radio, then power up, and key up the radio. measure the voltage at the place on the circuit board where the gate is soldered in place. Make a note, write down these voltages. let us know. then also after this, turn each bias adjust pot back and forth...

if a "golden screwdriver" tech got in there and adjusted the RF Amp bias pots incorrectly, it would cause this. VR 10/11/20 seen that before......

a friend sent me a few of those kits since he could not build them. and some other LDMOS VHF amplifier. so convert it to what?

so an old post, to a common problem. the first thing to do to any of these radios, especially if somebody has been playing inside the transmitter circuit, and touched by the "Golden Screwdriver" is to check the bias current on the RF driver and final transistors. if this bias is high, that...