ez80

Tony Duell ard at p850ug1.demon.co.uk
Sun Jul 18 13:44:38 CDT 2010


> 
> On 17 Jul 2010 at 19:01, Tony Duell wrote:
> 
> > You know you've been (hardware) hacking too long when you read the
> > subject: line of this message and assume it's going to be about a
> > biphase valve rectifier with a 6.3V heater and a B9A (noval) base.
> > Yes, that did happen to me...
> 
> Wrong side of the pond--here, it's a 6V4, not to be confused with a 

This _is_ an international list...

Is it just me, or are the common US valve numbers pretty much 
meaningless. The common UK/European ones, used by Philips/Mullard [1] can 
be easily decoded to give the heater rating, electrode structure and base 
type. US ones don't seem to give the electrode structure in any 
meaningful way, even though that it probably the most important thing [2].

[1] There were other codes used by manufacturers in Europe. One farily 
common one was the Mazda code. It looks like a US valve number (digits, 
letters, digits), but it's decoded in a totally different way. The first 
digits give the heater voltage _unless they're 10, 20, or 30, which means 
100mA, 200mA, 300mA for sereis-string sets), the letter gives the 
electrode structure (things like 'C' = frequency changer, 'L' = triode, 
'P' = pentode, 'D' = diode) but you dont' double up letters for repeated 
structures -- a double triode is 'L' not 'LL' And the last digits simply 
give unique numbers to valves which have the first part identical. A 6D1 
is a single diode (==EA50 IIRC), a 6D2 is a double diode (EB91/6AL5), a 
30P4 is a TV line output pentode, and so on

[2] Reminds me of a the large electronic component distributor over here 
that let you select 3 terminal fixed  regulators by just aobut every 
possible characteristic (case type, number of pins, max temperature , 
etc) _other than the output voltage. Odd, that' the thing I think of 
first when specifying such a component.

> type 80 rectifier (5V 4 pin base).  ez80 meant only one thing to me--

Ah, the type 80 I have come across...

-tony



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