Paul Goble wrote:
>
>Ian (et.al.):
>
>Excellent observation! I have been gathering information on
>Russian tubes for a relatively short amount of time; during this
>period, I've seen many "comparisons" between and amongst the
>Russian tubes and the Eimacs, RCAs, GEs, Burles, etc., of the
>world. I've OFTEN wondered how on earth folks arrived at their
>conclusions regarding "equivalency" - HI!!
>
>To me, "equivalent" means one can substitute one for another,
>with little or no electrical or mechanical change required.
>That's the way we thought of it with respect to the receiving
>tubes of yore - HI!
To be fair, "equivalent' has always been a rather elastic term. It can
range from exactly the same device from the same factory but with a
different number, out to as far as you care to stretch it.
To replace an 8877 with a GS35b would involve changing the socket, the
heater supply, the bias supply, the input circuit (different Z_in),
maybe the anode voltage, the output tank (different RL), the air cooling
setup, and quite probably the chassis and cabinet too, because the '35b
is significantly bigger. IMO that's stretching the elastic too far!
73 from Ian G3SEK Editor, 'The VHF/UHF DX Book'
'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.com/g3sek
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