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[AMPS] Eimac 4CX600J comments?

To: <>
Subject: [AMPS] Eimac 4CX600J comments?
From: (Radio WC6W)
Date: Mon, 08 Feb 1999 19:19:41 EST

On Sun, 07 Feb 1999 19:56:37 Scott Townley <> writes:
>I was just browsing thru my Eimac catalog and noticed the
>4CX600J...designed for AB1 service, low IMD specs, reasonable PS
>requirements, could use the ubiquitous 4X150/4CX250 sockets...
>I'm curious why I've not seen these in use in amateur equipment.  
>Seems a pair of them would be preferred to a single 4CX1000A (total grid
>2W instead of 0W; plus 200W reserve plate diss.).  Is there a rap on 
>these or are they "undiscovered"?
>Just curious...thanks in advance.

Hi Scott,
    I've always thought that they were kinda cute myself... ever since I
inherited a couple of them (actually the 4CX600JA's with the larger
radiator) but, they do have there own peculiarities.

   1.  The pinout/socket is NOT identical to the 4CX250's;  the center
pin & the pin that is always missing from the 250' sockets are for the
heater.   The cathode & grid are on two triangular arrangements of three

   2.  They do run at a much more favorable bias point so, with much less
dissipation they can output almost as much useful low distortion power as
a 4CX1500B.

   3.  They aren't much use above 30 MHz due to derating and the inferior

   4.  They are extraordinarily pricey (for their size / ratings) if
purchased new.   This is likely the reason for no amateur usage.  I did
discover that they are used as paperweights (and sold really cheap) in
the central Texas area; pulls from airborne radios 

   5.  ...and finally, when did most hams give a hoot about IMD.  :-)
  Marv  WC6W


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