Why does everyone insist that the 4-1000 needs in excess of 5kV to run legal
limit? I have built several that easily put out 1500W with only 4-4.5 kV
and 100W from a solid state rig. Am I just using good tubes vs. ones near
the end of life? Probably.
I would use bandpass coax stubs to keep harmonics down with only an "L"
network.
Mike, W1NR
-----Original Message-----
From: owner-amps@contesting.com [mailto:owner-amps@contesting.com]On
Behalf Of Peter Chadwick
Sent: Thursday, January 03, 2002 3:59 AM
To: amps@contesting.com; 'wlfuqu00@uky.edu'
Subject: RE: [AMPS] Building new 4-1000A amp
I used an L network in a marine tx many years ago: the antenna load for test
purposes in the 1.6 - 3.8MHz band was 10 ohms in series with 250pF, so an L
network gave adequate harmonic rejection. The working Q came out at 15 in
that
case, so the losses were manageable. We sold several hundred of them, so I
guess
they can't have been too bad.
I gather from what's been said here in the past that you need 5 or 6kV on
the
plate, but I guess you knew that already.
73
Peter G3RZP
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