Don,
You said, "paralleled 800MFD, 450VDC caps". I think you mean series. I
wonder how clean the plate voltage needs to be for a tube tester? If you use
the mega-capacitor bank, consider a suitable series resistor to limit the
peak current in the event of a short circuit to somet
Don,
You said, "paralleled 800MFD, 450VDC caps". I think you mean series. I
wonder how clean the plate voltage needs to be for a tube tester? If you use
the mega-capacitor bank, consider a suitable series resistor to limit the
peak current in the event of a short circuit to somet
Does, anyone know of a source for audio mods for the B&W 5100B
transmitter. I wonder if anyone has tried to modulate the screens in
addition to the plate of the finals. It appears the screens use a different
power supply than the plates of the finals.
Thank You
Tom Elmore KA1NVZ
Anchorage Ala
Mark,
I haven't been part of this discussion so far, but would be interested in seeing
the schematic for your tube curve tracer. I've thought about building a tester
for
transmitting tubes, but haven't gotten past the thinking stage. I guess one way
would be to build an oscillator circuit and t
Gentleman I apologize to the list, that last posting should have been
to a email address for an individual and not to the list!
However now that I have your attention, I still have a very nice EAC R390A
and a nice SX-28 with matching speaker that I would be willing to put in
trade for a NC-183D
TRANSCONDUCTANCE can be checked by placing a audio XFMR speaker winding in
series with the plate lead and measuring output voltage from the other
winding. The ratio of grid input voltage change from a 60 cycle source
DELTA Eg : to the measured output would be a relative value that would need
to be
Bob I would be willing to pay the shipping if you would ship the HRO-50. You
could even take it to a pack n mail place that has 'foam in place' packaging
and I'll pay the cost of getting it packaged, insured, and shipped. And I'll
pay half to ship the 390 to YOU in the same fashion.
whatcha thi
Hey Don,
Sounds good!
How would you like to build a curve tracer also?
I built a tube curve tracer for audio tubes about 10 years ago. I found the
schematic the other day. Come to think of it I also have the the actual unit.
The idea is to use unfiltered half wave as the plate supply -
Just thought I'd throw out an update on this. I am building an emission tester
for older, mostly 800-series transmitting triodes. It will be able to measure
emission current at zero bias or adjustable bias (using an external bias
supply) at any plate voltage up to about 2500V. The HV is full-wav
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