[Amps] Mounting Plate for a 3CX3000A7

Chris Wilson chris at chriswilson.tv
Thu Jan 3 19:35:57 EST 2013

> ##  The 3CX-3000A7  socket and mating grid ring is available  from
> RF parts.    It’s identical to the one used in the Henry radio 8K ultra.
> It was $275.00   in the mid 90’s.   Last I saw, it’s now $375.00   
> That does not include the chimney.  Eimac doers NOT make a chimney
> for the 3CX-3000A7, nor the 3CX-6000A7.  
> The way to get around the chimney problem is to build a wooden box
> around the tube... with either a teflon or micarta top.   The hole
> in the top is .005” bigger diam than the OD of the tube. 

> ##  the socket sold by RF parts is a thing of beauty. It will
> handle100A  CCS  of fil current easily.   It uses a double row, one
> above the other of silver soldered finger stock for the outer fil collet.
> The inner consists of a hollow tube with a clip  sitting in a
> recessed groove.  The 3x3 and 3x6 tubes use a coaxial  fil assy.  
> The grid ring is .125” thick and  4.25”  diam.  Both grid ring and socket
> are silver plated, then entire mess is silver plated.    That
> socket is used for both the 3CX-3000A7 and also the 3CX-6000A7. 

> ##  some will use the F7  version of the 3x3 tube..which uses  3 x
> flex leads.  2 for the fil and 1 for the grid.   The grid lead is
> unbolted and tossed....and replaced with the flange from a vac cap.
> Then its just a case of bolting the flange to the chassis..and
> running the flex leads for the fil over to the bifilar. 

> Jim  VE7RF 

04/01/2013 00:28

Jim, if the 3CX-3000A7 in my Henry RF generator I am converting turns
out to be a duffer, or fails prematurely (I have had filament power
and the blower on for a few hours, but not had the HV on the plate
yet), can I put in an F7 version? My pal has several brand new boxed
F7 versions, but no A7's. Thanks! Whilst I have your ear I have also
got from my pal a new Bird 10kW water cooled dummy load. I am about to
plumb it in in the attic where my shack is. I have the choice of
running 3/4" or 15 mm hard pipe from the house water riser to it. Will
15 mm copper flow enough? I won't be running the load at full whack :)

       Best Regards,
                   Chris Wilson.

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