Baron wrote:
David Brodbeck wrote:

Dave Platt wrote:
In article ,
David Brodbeck wrote:

Good thought! No such luck, though. Looking at the schematic, if
there were such a jumper it also would null at 200 ohms when the
"range expander" switch is on, and it doesn't.

I think when I get time I'm going to check the transformer windings
for
continuity...maybe someone transmitted into it and blew a winding.
It looks from the schematic like this little toroidal transformer
would be "first in line" to get zapped.
Yup. Not an uncommon way for these devices to go to Tumbolia. The
pot might also have gotten cooked.
Well, I'm stumped. The pot tests fine. The windings on the toroidal
transformer have continuity, and none are shorted to each other. It
seems like it ought to work, but I continue to not get a useful null
for resistance -- it just gets quieter the closer to zero I turn the
knob. The inductance/reactance knob works, though -- I can get sharp
nulls with it.

What are you trying to test it with ?


I tried a few different fixed resistors connected to the "unknown"
connection. I also tried leaving the "unknown" connection open and
engaging the range expander feature, which should give a null at 200
ohms. (The range expander just parallels a 200 ohm resistor with the
unknown.)