[EMAIL PROTECTED] wrote:
Deep in the bowels of my junk I found some resistors for a test of the whole
modulation section of the Gates BC-1T. I put five large-ish (each like a roll
of quarters, maybe 50 watts?) 800-ohm wirewounds in series across the
secondary of the modulation transformer. Thaty would seem a good load: 4000 ohms. I
put an RMS voltmeter across one of the resistors in the stack.
Applied tone to the input... enough drive to produce 200 mA of combined
modulator current produced about 100 volts across the one resistor. 400 mA got me
about 200 volts. And the tube plates were medium-glowing at 0.2 A (what I'd
consider normal for 833 modulators) and quite brightly glowing (more than I'd
like to see on an 833) at 0.4 A.
Didn't run it too long, but after I shut it down the resistors were hardly
warm at all.
Steve WD8DAS
Hate to say it, Steve, but I think your modulation transformer is fried.
Had a similar thing happen with a Ranger I mod xfrmr... plenty of plate
current on the 1614's... excessive, in fact. Just no, or very low
modulation. Turned out be a blown mod tranny.
Good Luck!
--
73
-W5OMR (home for 2 days)
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