Feeding audio to the Bauer 707 transmitter

[kc4mne]

Hooking up an innovonics 222 to my Bauer. The 222 supports asymmetrical peak limiting so audio "polarity" or "phase" is important. The innovonics instruction's state: "The processor output should be connected so that a positive going waveform at the + output terminal yields positive carrier modulation."  The audio input terminals on the Bauer are not labeled. How do I establish with terminal on the Bauer will yield positive carrier modulation on a positive going waveform?

[W8IXY]

Either monitor the modulation on a modulation monitor, or look at the waveform on a 'scope.

73
Ted  W8IXY

[Mike/W8BAC]

Hi Manuel, The simplest way is to just hook it up and watch your mod monitor or scope. Set your mixer gain to between -2 and zero for peaks with voice and turn the transmitter input gain all the way off on the 222. Key up the Bauer and bring up the gain until you fill the envelope. I don't know if the 222 has an audio oscillator but a 1000 cps tone will do a better job than your voice. Use the same method with the tone but keep the transmission short. You will see if your out of phase.

Keep in mind the mod iron in most older tube type transmitters wasn't designed for much over 100% and can be damaged easily by some newer processors that push the positive peaks beyond design specifications.  Good luck and have fun.

Mike

Nice looking shack! Found your picture on QRZ