Now that both my Gonset Communicator II and my Heathkit Twoer are working well enough (see my prior threads, thanks to all for the help), my next project is to get them working with VFO control. Picked up a Johnson 6N2 VFO for the task.
The VFO appears to be working, at least to some extent, the tube lights up and a frequency counter shows output on 8 mhz. And when connected to the Gonset, there does appear to be a small bit of output at the pertinent 2 meter frequency. But it is not what it should be, the magic eye barely moves when tuning up (it closes almost completely with a crystal).
There may be an easy solution to the problem. On page 7 of the 6N2 VFO manual (available at http://qsl.net/nz5n/Johnson6N2VFO.pdf
), it states that, in a "pentode cathode-feedback oscillator," it is necessary to "remove the feedback so the crystal stage does not act as a self-excited oscillator" by shorting out the RF choke in the cathode circuit. The Gonset has a 6CL6 pentode oscillator (see schematic at http://qsl.net/nz5n/Gonset%20Communicator%20II%20schematic%20no%20parts%20list.pdf
), and it has a choke (RFC 1) on the cathode. So maybe all I need to do is short this choke.
However, thought I'd ask here before shorting anything. The Gonset 3357 is a similar VFO designed specifically for the Communicator, but the manual for the 3357 (available at http://qsl.net/nz5n/Gonsetvfo3357.pdf
) says nothing about shorting any choke or making any other mods to the Communicator's oscillator.
Any thoughts? Should I short the choke (would prefer not to, as this would disable the ability to use crystal control unless some sort of switch is added), or is there something else to try first?
73, Bill NZ5N