B&K E200D Signal Generator Mods.

[unit_399]

I have a B&K E200D rf signal generator that was given to me by a retired tech here years ago. Like brand new. After cap replacement and realignment (it was spot-on), it became part of my everyday test equipment. Only problem is that with the analog dial, it is very difficult to latch on to a specific frequency, say 27.185. It wanders all over the place. But once set, it's stable. I want to add an additional variable cap as a fine tuning adjustment in series with the main tuning cap.
Any suggestions as to what cap value I should use ?? I want to use a 2nd air variable, but don't have any of those in my shop. What should I order ?? Anyone .

- J.J. 399

 

[nomadradio]

in series with the main tuning cap.

I would suggest in parallel. This will move the dial's calibration. You can tweak the factory trimmer to bring the dial back to calibration. I have seen 1N4001 rectifiers used as a varactor for fine tuning. For that matter, a real varactor in series with a smaller disc cap might be easier. Or a small 10pf or so varactor. Just so the tuning-voltage source is well regulated.

73