[Boatanchors] WYB: Octal triode 6C4 or 6S4 - I meant WTB WTT:6C4S or 6S4C

[Richard Knoppow]

----- Original Message ----- 
From: <WA5CAB at cs.com>
To: <boatanchors at mailman.qth.net>; 
<milsurplus at mailman.qth.net>
Sent: Friday, October 14, 2011 7:57 PM
Subject: Re: [Boatanchors] WYB: Octal triode 6C4 or 6S4 - I 
meant WTB WTT:6C4S or 6S4C


> OK.  Someone already said once that a 6C4 is a 7-pin 
> miniature (which is
> true) and that a 6S4 is 9-pin (I don't happen to know the 
> tube and didn't
> check but it probably is).  But even without looking up 
> the tubes in a tube
> manual, neither one could possibly be an octal triode 
> unless it had a directly
> heated cathode.  Which AFAIK were not built with 6.3 volt 
> heaters.

     I suspect the 6C4 is actually a 6C5, which is a metal 
octal triode often used as an oscillator tube. Not sure 
about the other tube but it might be a 6S7 which is an octal 
remote cut-off pentode with a grid cap similar to a 6K7 but 
with a low current heater. But, there is also a 6S6, a 
semi-remote cut-off pentode, and a 6S5, an octal base 
magic-eye tube. There may be others my old handbooks don't 
show. I don't think I have any of either. The 6C5 at least 
was a fairly common tube and should not be too difficult to 
find. If the other is, in fact, a 6S7 a 6K7 would probably 
work provided the heater supply won't be overloaded.
     FWIW I could find only one tube, the 6B4G, with an 
octal base and filamentary heater. There may be others but 
they must be very obscure.


--
Richard Knoppow
Los Angeles
WB6KBL
dickburk at ix.netcom.com