Recent content by SuperLid

I spoke to the designer, who said it was a Troy thing, that is not going to happen.

Ground the emitter of the keying transistor, which will key the amp. Do this with NO RF input. Then measure, the DC voltage from the RF transistors bases, to ground. If there is AB bias, you should see .6-.7 volts on the bases.

The DDS VFO I ordered from Scamazon, was defective. Zero output. This has turned out to be a major PITA. Someone has to have one of the model 6 things hanging around.

Interesting reply. I also have screengrabs from Mike's video, of the coil and caps. I can count what I *believe* is 13 turns and 10 pF in series and one in parallel. I really don't want to spend a lot of time figuring this out. The DDS VFO's out there now, are very appealing and I have one to...

The 6 does not operate at 23 MHz, it is 7.8 Mhz. The 6 was added later, as the early owners manuals state that the radios that use the 23 MHz crystals, will not work with the VFO. Later versions of the manual, that show the model 6, show the operating freq as 7.8 x 3 to get to 23 MHz. The radio...

Nope....L value is unknown. SL

Ooops. I didn't look.

I don't know that part. But, the MPSH10 is available in SMT, MMBTH10.

This is done all day, every day. Look at the transmitters that are used for real estate sales, drive in movies, halloween and xmas light displays. I have one of these things in my storage that was used for real estate. Figure out the frequencies and power level for license free operation and...

I need the LC values for the elusive model 6 VFO. The factory documents do not have this info. L2 turns and C13, C14 and C15 (or whatever cap combination that was used). Thanks, SL

Gain is not the answer. NF is....

The 1st RF amp, should have the lowest noise figure in the chain. Everything after the 1st, amplifies the noise of that stage. Try to get your hands on 2SC1730 or MPSH10.

The major difference between germanium and schottky, is the forward voltage drop. The schottky tends to be slightly lower, than the germanium. When increasing the voltages to the AGC circuit, that is when things get nasty. Overshoot, overload and has absolutely nothing to contribute, in reducing...

It's snake oil. None of those parts will do any good, some may make things worse. When I see a shottky mod, I reverse it back to germanium. I have used MPSH10's in the RX amp stages and RX pre-amps in linyeeers with success.

Every RF circuit has it's limits. The radio is not designed for 21 MHz operation. 21 MHz is beyond the design limits. Be happy with what you have, it is nice when the upper bands are closed and 15m is open. I measure 49 Watts PEP on mine at 21 MHz.