w5omr at satx.rr.com
Sat Jun 10 11:01:44 EDT 2006
Donald Chester wrote:
>> Would be around 35w DC input (250v @ 125mA on the final). What I'm
>> wondering, will the BTCL 10-80 band switch handle that much power?
> I would say so. You are talking about only 20w or so of rf.
It's an interesting idea, Don. One dual-triode in the final (balanced,
link-coupled, push-pull) modulated by a pair of dual-triodes, in
250VDC @ 500mA should be plenty sufficient for a power supply. One
could almost simply recify 120vAC, and build a voltage doubler, for the
For saftey's sake, I would use a 1:1 isolation transformer.
I'm gonna mull this over, a while. I've got some 6AS7's, and a good
100w Modulation transformer (more is better!) Then, when needed, that
plate modulated signal could be fed into the current project, which is a
single 450TL linear amplifier. That kind of power isn't needed on 15m or
Lessee... one-half of a 12AX7 for the mic input, outputted to the 2nd
half of the same tube, with inverse feed-back back to the mic input
stage, fed into a phase splitter, into another 12AX7 for push-pull
audio, capacitivly coupled to the grids of the modulator tubes.
A Johnson VF-122 vfo into a 6AU6 for grid drive to the final, and a
fixed bias supply on the final grids...
The whole rig (minus the power supply and mod transformer) could
probably fit on a 9x12 cake-pan sized chassis.
Driving your AM Rig without a scope,
is like driving your car at night, without headlights. (K4KYV)
73 = Best Regards,
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