[ARC5] Replacing the 12v tubes with 6volt types

[mac]

Along the same line I checked the voltage drops across the individual  
series wired 1625 PA tubes in a stock 274N transmitter a while back  
and found a surprisingly wide variation one set of tubes to the  
next.   Worst case observed in a population of a couple dozen examples  
(mixture of NOS and other) was something around 10 volts on one tube  
and 14 volts across the filament of the other.  Worth checking out  
before running a new set for any length  of time, re-tubing, etc.

Dennis D.  W7QHO
Glendale, CA

*******************
On Oct 18, 2012, at 3:54 PM, WA5CAB at cs.com wrote (in part):

> I'm surprised, considering how long this sub-thread has continued,  
> that no
> one has mentioned the obvious.  The first criteria for s 6 volt tube  
> to
> replace the 12A6 is that it draw the same filament current as a  
> 6SR7, which is
> what it will be in series with.
>
> 6SR7     300 mA
> 6C5       300 mA
> 6F6       700 mA
> 6K6       400 mA
> 6L6       900 mA
> 6V6       450mA
> 6W6      1200 mA
>
>
> Home: http://mailman.qth.net/mailman/listinfo/arc5
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:ARC5 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html