# Schematics of Atanasoff-Berry Computer logic circuits?

Tony Duell ard at p850ug1.demon.co.uk
Sun Aug 31 13:39:34 CDT 2008

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> As per the 1982 Amateur Radio Handbook, ECC83 (and ECC82) are double
> triodes.  Type 83 is described as a half wave rectifier in the 1951

Correct, but I think you've misinterpetted what I was saying.

Philips/Mullard valve numbers are actually quite informative, and can be
decoded as follows :

First letter gives the heater/filament rating :
A = 4V
B = 180mA???
C = 200mA
D = 1.5V
E = 6.3V
G = 5V (early-ish ones, later used for miscellaneous ratings)
H = 12.6V?
K = 2V
O = Semiconductor (no heater)
P = 300mA
U = 100mA
Y = 450mA

(Where a current is given, the valve was intended for series-string
operation)

Subsequent letters give the electrode structure. For multi-section vales,
they're given in alphabetical order
A = diode
B = double diode
C = triode
D = power/output triode
E = signal tetrode
F = signal pentode
H = hextode/heptode
K = heptode (phantom-cathode tpye of fequency changer)/octode
L = power/output tetrode/pentode
M = tuning indicator ('magic eye')
N = thyratron (gas-filled triode/tetrode)
Q = nonode
X = gass-filed full-wave rectifier
Y = half-wave rectifier
Z = vaccume full-wave rectifier

The first digit gives the base type
None/1 = miscllaneous (often only a single-digit number means P side
contact base)
2 = B8B 'Loctal' For 3-digit numbers, 2 = B10B
3 = International Octal
4 = B8A Rimlock
5 = B9G. For 3 digit numbers, 5 = B9D
6,7 Subminiatores
8 = B9A Noval
9 = B7G (7 pin miniatore)

Other digits distinguish between valves where the rest of the code is
the same.

Now the oroginal poster was talking about some 12V-anode-voltage valves.
He'd rememebrs are frequency changer -- a triode hexode -- with an ECHnn
bumber. I beleive the full number of that valve is the ECH83. And that
the EBF83, and possibly the EF83 are als 12V anode types.

This has nothing to do with the the American type 83 rectifier valve

-tony

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