[Amps] Still looking for 7.5 volt, 42+ Amp filament

[Jim Thomson]

Date: Fri, 13 Feb 2015 15:41:18 -0600
From: Ed Hatcher <ed.kv5i at gmail.com>
To: amps at contesting.com
Subject: [Amps] Still looking for 7.5 volt, 42+ Amp filament
transformer

Close to North Texas if possible.
73,
Ed-kv5i

##  U may have to get one from hammond, who bought out the dahl line,,,or else where.
Plenty of xfmr makers. 

##  IF using a bifilar, even real heavy duty type, watch out, the fil V at the socket  will be slightly 
less than at the xfmr output..... under load.    My 3CX-3000A7 is  7.5 v  at 50 A.     Bifilar
is rated for 60A  CCS.   Fil V at the socket, even with rock solid connections is only  7.1  or 7.2 v.
No big deal in my case, since the xfmr I used is a 8.25vac  at 80A  CCS  unit..with a 208 vac
single phase input.   I have to use a small variac anyway... to drop the V down to where I want it. 

## But to get 7.5 vac  at the socket, requires 7.9 vac at the xfmr lugs... UNDER load of 50A. 
##  On my  3CX-6000A7 tube, it is 7.0 vac  at 80A CCS..at the socket.   I had to use a 7.5 vac
rated xfmr...80A  CCS... plus variac,  to get 7.0 vac  at the socket...again,  I lost .4 vac through the
80A CCS  rated bifilar. 

##  Just something to be aware of.  If u get a custom built one, get a few taps on the primary.

Jim   VE7RF