High Voltage problem? Well, I think I have that sorted-out
and it wasn't the switching transistors; it caught a case of
the "oops." You know, voltage doublers work so much
better when you connect both electrolytics with the
proper polarity.... DOH!
I ran out of time (as usual) before I could correct it,
but I'll get back to it as soon as work lets go of my hair.
Anyways- here's the latest request for opinions.
I'm attaching the transmitter circuit diagram.
Reduced the five crystal channels to one on the diagram.
These rigs typically have movable taps on tank coils,
and loading coils (think of an ARC-5's roller),
one tap for each channel.
I don't want to fuzzle-around with swapping coil taps
and tuning caps with the PA "live" drawing excess current
while I "muddy the waters" looking for the right taps.
So here's the plan- I will disable the High Voltage, light
the tube filaments and use a signal generator to inject
3885 KC on the PA signal grid, connect the rig to a
50-ohm dummy load, monitor for the signal at the
load with a scope and move taps/tune caps for max
signal across the load. If it does the "Milrig" deal
where it won't tune 50-Ohms, a series cap will fix it.
That way, when I restore High Voltage, the rig
should be close to correctly tuned.
What do you think?
TNX OM ES 73 DE Dave AB5S
P.S. Grid dip meters are a non-starter.
I never have good results with those things.
In fact, I've given-away the ones I had.
