Ian, Peter V, Peter C,
You are 100% correct in your spot-on the mark comments below!
Much nonsense has been promulgated on this forum to the contrary :-(
A savvy RF amplifier designer can indeed extract perfectly adequate IMD
performance from any of the aforementioned and often unfairly maligned
tetrodes when used in grid-driven linear AB1 SSB amplifiers.
It's no accident that all of the adept European ham amplifier manufacturers
deploy tetrodes in their designs and commercial products. Plus there remains
an abundance of excellent NOS surplus military SSB and linear TV amp tubes
in the marketplace at reasonable prices that make these niche companies
viable and enduring. Broadcast transmitters were also largely tetrode based.
Properly designed and properly operated, a tetrode based SSB linear amp will
exhibit spectral purity performance that's on par with that of any triode
based amplifier.
Leigh
VK5KLT
-----Original Message-----
From: Amps [mailto:amps-bounces@contesting.com] On Behalf Of Ian White
GM3SEK
Sent: Tuesday, 30 October 2012 1:58 AM
To: amps@contesting.com
Subject: Re: [Amps] The GU84B and GU78B tubes / some brief history
Carl Wrote:
>> By the way, no European manufacturer ever used triodes for RF amplifiers
>> except before the time tetrodes were invented.
>Thats why G3SEK had to develop those excellent tetrode boards before
>WW3 started in Europe from all the crummy signals.
>
>Carl
>KM1H
Not quite... I originally developed the Tetrode Boards because of all
the crummy signals from 4CX250Bs!
The differences between triodes and tetrodes are far less important than
the differences between individual amplifier designs, and the ways that
individual people try to operate them.
--
73 from Ian GM3SEK
http://www.ifwtech.co.uk/g3sek
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