This is a Siltronix Model 90 VFO I worked on for a friend. Siltronix equipment was basically the 11m division of Swan / Signet, hence the similarities. These were common place on CB rigs of the past, but are GREAT on older ham rigs as an external VFO and as a replacement for crystals.
This one already had a digital programmable freq counter installed. In 12 hrs it would wander 20.0+ khz. I modified it and installed a voltage regulator in the osc supply, removed all the flex wiring in the freq determining circuits and installed rigid copper, bonded the circuit board to the chassis, and adjusted the vfo coil for proper operation. It now only drifts 1.5-2 khz in a 24 hr period.
Hint #1: 2 caps in the osc can move this from 1.5mhz to over 30mhz... Great hamfest finds and easy to mod. The freq display only runs about $15 on Amazon.
Hint #2: The model #90 has a 5 position band switch in the lower LH side of the front panel. The first 2 positions select different cap values (the dial has about 400khz band spread). The other 3 positions are for crystals, but can be rewired to select different cap values, as well. Since it's a 5pDt switch, the other part of the switch can be used to select presets in the freq counter offset. That would be handy on older rigs where you might use the fundamental freq on 160, 80, or 40 meters, but may use the 2nd harmonic on 20m, 3rd harmonic on 15m, etc. Very handy!
The Model 80 is basically the same vfo without the band switch and such.
