[Amps] Mounting Plate for a 3CX3000A7

Jim Thomson jim.thom at telus.net
Thu Jan 3 05:02:00 EST 2013

Date: Tue, 1 Jan 2013 23:45:20 +0000 (GMT)
From: DAVE WHITE <mausoptik at btinternet.com>
To: amps at contesting.com, Ed McKie <kb5gt at cableone.net>
Subject: Re: [Amps] Mounting Plate for a 3CX3000A7

I seem to remember getting one from RF Parts about 10-15 years ago.? I don't know if they still stock them.? There was a separate grid ring and filament filament assembly.? It's been in reliable service in my amp for over a decade now.


Dave G0OIL

--- On Tue, 1/1/13, Ed McKie <kb5gt at cableone.net> wrote:

From: Ed McKie <kb5gt at cableone.net>
Subject: [Amps] Mounting Plate for a 3CX3000A7
To: amps at contesting.com
Date: Tuesday, 1 January, 2013, 0:36

Anyone know if a pre-drilled, pre-cut mounting plate for a 3CX3000A7 is

Ed,? KB5GT

##  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 

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