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Old 3rd October 2004, 09:35 PM   #1
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Question i have a matched pair of 3cx1000a7..

ok guys;
I know that the 3cx1000 is a high power transmitting tube,
but is there any chance to use it as a poweramplifier for audio?
would it be possible at all?
are there no way to get rid of any possible oscillations?
is OTL out of question?

tnx for any help!
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Old 3rd October 2004, 09:46 PM   #2
Yvesm is offline Yvesm  France
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Old 4th October 2004, 02:18 AM   #3
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How much ya want for 'em? I have a need for chunky tubes, building an induction furnace.

Hmm...breechblock socket...where the heck would I get that...

Tim
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Old 4th October 2004, 02:31 AM   #4
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Hi,

Quote:
Hmm...breechblock socket...where the heck would I get that...
Either HAM or from Richardson Electronics.

Cheers,
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Old 4th October 2004, 05:04 AM   #5
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Quote:
Originally posted by Sch3mat1c
Hmm...breechblock socket...where the heck would I get that...
There's a few DIY socket designs on the net as well as a proven one in the ARRL Radio Amateur's Handbook.
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Old 4th October 2004, 05:11 AM   #6
SY is offline SY  United States
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As far as audio use, the tube requires forced-air cooling. That means noise. It also requires ultra-high voltages and difficult output iron to take advantage of its characteristics. Sell 'em and buy a few sets of 13E1s or a big pile of PL509s.
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Old 4th October 2004, 08:33 AM   #7
Knarf is offline Knarf  Denmark
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Are you sure they are not a pair of either 3CX1500A7 (aka. 8877) or 4CX1000 ? I don't think there is any such tube type as a 3CX1000...

In any case, then, as has already been said, these are pretty useless for audio. You cannot even safely apply heater power, without the tube(s) sitting in the proper 'air system' cooling socket and with proper forced air cooling running. Even finding a fan, which can supply the needed back pressure will be difficult, your average fan from an old Xerox machine will be useless here.

Ie. they are noisy when operated according to specs, even if you just apply heater power.

If they are indeed one of the types I mentioned and new too (how were they 'matched'??), then you will be able to sell them to radio amateurs, who use these in high power transmitters.

Frank.
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Old 4th October 2004, 09:05 AM   #8
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Hi,

Quote:
I don't think there is any such tube type as a 3CX1000...
There used to be...

HISTORY.

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Old 4th October 2004, 09:29 PM   #9
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And straight from the horse's mouth:

http://www.cpii.com/eimac/catalog/140208.htm

As for data, I'd link to Frank's but he only has a 10k datasheet.

Tim
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