>At 12:44 PM 4/21/97 -0700, WA2MOE wrote:
>>no flames...what are "handles" on tubes?
>>
Large external anode ceramic tubes, generally 5 KW plate dissipation
and up, have built-in handles to facilitate insertion/removal from
their sockets. Some large tubes, for example the 3CX15000B7 which is
the big brother of the 8877 requires no socket. It just bolts to the
chassis, but it still has handles. Dropping one of these brutes would
be enough to make a grown man cry like a baby!
Some of you may ask "why would ANYONE put such a tube into amateur service?"
1. As stated above, no socket required.
2. It only takes 68 more watts to light the filament than a 4-1000A. (225w)
3. Resonant load Z=1000 ohms; input Z=24 ohms (just like a pair of 8877's)
4. Can be driven well above legal limit with a 100w exciter.
5. Amplification factor: 200
6. IMD-Outstanding! (Eimac's words, not mine)
7. I saved the best for last; good "pulls" sell for $400 up.
If you research the history of Collins commercial/military amplifiers,
you will find that most of them were rated at a maximum power which was
always around half of the plate dissipation of the final tube/s used.
This probably made Eimac very sad indeed!
(((73)))
Phil, K5PC
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