Amps
[Top] [All Lists]

Re: [Amps] stability of amps

To: <doc@kd4e.com>, <amps@contesting.com>
Subject: Re: [Amps] stability of amps
From: "Tom Rauch" <w8ji@contesting.com>
Reply-to: Tom Rauch <w8ji@contesting.com>
Date: Tue, 25 Sep 2007 11:34:36 -0400
List-post: <mailto:amps@contesting.com>
The nay-sayers suggest that this 
http://www.qsl.net/ve5ri/cyclops.htm
successful 160-10M contest-tested Eimac 4CX1500B power 
tetrode amp
is sub-standard in design and may suffer as to spectral 
purity.>>

Well, you weren't clear about what amp. When I went to that 
link I found a 3CX3000, not a 3CX1500.


Have you measured one built like this with the same tube and
found any of those negative claims to be true?>>

Not with a 4CX1500. Unless you buy them surplus for next to 
nothing there is little reason to build one. They aren't as 
clean as an 8877 or almost any grounded grid triode, and 
overall they are more complicated to build properly.

I am curious if the negative assertions are true or are mere
extrapolation from other tubes in vaguely similar designs.>>

I looked at the 4CX3000A.

I am also curious if the amp adds impurities or if most of
any garbage may be spectral impurities amplified from the
driver used in the tests performed by some.>>

I can't speak for others but I use a very clean driver. I 
run two radios through a combiner into a class A 8877 triode 
at 0-200 watts. IM is -80dB in the test fixture.


Things work they way they work Doc. There is no magic.

73 Tom 


_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps

<Prev in Thread] Current Thread [Next in Thread>