I am confused reading this:
>Secondly i would caution anyone about buying these tubes without some
>sort of guarentee or tests for power out put. I bought a surplus
>shipment of 16 tubes, at the end i had 4 good ones, still a bargain.
>But these surplus tubes are generally run in continous duty broadcast
>service and well down on power.
>Igor
What exactly is 'well down on power'? I assume that a 10,000D would be
able to supply 10-15 kW easily in broadcast service. In amateur service,
wouldn't it be OK if it would only supply, say 7 kW! Loss of emission from
the orignal filament capability might be a problem for full power, but
enterprising operators could nurse a weakened tube and still burn a hole in
the ozone, right? Besides the price is right for pullouts.
I have a pile of 4CW100,000D tetrodes (14) that will eventually be salvaged
through 'appropiate' channels, such as bids, surplus auctions. I am mildly
curious if any amateurs would use them, such as the power mongers on this
list? They are not too much bigger than your 10K, long and skinny, and the
sockets are large. The filaments will emit a lot of electrons, though.
You'd definitely use 3 phase AC for the plate supply to push these tubes.
Most people in the RF power business prefer the 50,000/100,000/150,000E
version, as it is fat and short and has lower inductance in the electrode
connections - more stable for HF amplifiers. The 100,000D has ended up in
a lot of old amplitude modulators and MW RF stages though.
73
K5PRO
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