25 Apr
2005
25 Apr
'05
6 p.m.
Subject: Re: small valves and RE: OT
From: ard at p850ug1.demon.co.uk (Tony Duell)
Date: Tue, 26 Apr 2005 00:13:41 +0100 (BST)
To: cctalk at classiccmp.org
Sure.... The reason I looked up the equivalents is that I don't know US
valve numbers that well, and they don't tell me that much cabout the
valve. The Philips/Mullard numbers are much more useful in that respsect
-- the initial 'D' means a 1.5V filament (E would be 6.3V, etc), the
other letters give the electrode structure (A = diode, F = signal
pentode, K = heptode or octode frequency changer, with the phantom
cathode type of design (H would be a hexode or heptode designed for a
separate oscillator), L = output pentode, etc...) and the '9' tells me
it's a 7 pin miniature base (B7G).
I also have a Phillips/Mullard and Eimac manuals. I should have used
numbers more common there. I see both here so it's no big deal. For
example a homebrew RX for 80/75m uses an eclectic mix, 6AN8 Mix/LO,
6AU6 455khz IF, 6BH6 455khz regenerative detector, 6DS4 BFO, and an
ELC84 first audio and power output. All built into a 7x7x2.5" chassis
with power transformer and all stages shielded as needed. Works
very nice.
Sure. My warning, again, was based on the fact that
you're likely to get
inside the set (but as I said, I am sure you realised the dangers anyhow).
The dangers are less here with 117V nominal mains. However I've been
at this racket for over 35 years. It's usually me telling others to
be careful and lockout/tagout.
The local
station for RED SOX baseball is WEEI 850khz! It's the best
AM radio I have. I have spares for the tubes.
My comment was not 'why would you want to listen to that radio' (that is
obvious, valve radios are good to listen to), but 'why would you want to
listen to sports when there's plenty of hacking to do' ;-)