> Curious question -- I recently wondered why it is that the 3-1000Z
> was never that popular a tube in amateur circles, but the 3-500Z was.
> Why did many amateur designs use two 3-500Zs instead of one 3-1000Z.
> Seems like it would simplify things. One bottle and you could to the
> legal limit with a simple grounded-grid circuit.
I wonder about that myself. BTI, and 2-3 others made ham amps with the
1000Z, and maybe 3-4 commercial amps had them. I have seen 1-2 RF Generators
that used them. Perhaps many hams are under the delusion that only one tube
will fail at a time while the other(s) remain(s) at 100% output, and a new
over-the-counter replacement will always match the old tube in emission;
keeping replacement costs down. When power limitations were increased to
1500 watts, glass tubes were on their way out. A pair of 500Z's or a single
1000Z have little head-room @ 1500 watts out. Then came the 8877 and other
triodes which made life more simpler, were more robust,(700 watts of
head-room at 1500 watts out) and were built at closer tolerances, dooming
the big glass bottles to obsolescence.
(((73)))
Phil Clements, K5PC
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