[Collins] Manual Changes

[David Knepper]

With only 150 of these units ever being manufactured by Collins in =
around 1948 and 1949, you would have thought that there would have been =
some degree of standardization - WRONG. =20

I have two units under restoration.  I thought that the bias and screen =
supply decks would be interchangeable.   After about an hour or so of =
pulling the units in and out.  (They are not light) I noticed that  Pin =
5 is tied to the primary power transformer on the one deck but on the =
other low voltage power supply deck, pin 5 has no connection.  I spent =
about an hour trying to figure out why the one deck would not work in =
the one 30K-1.   Had I referred to both schematics - which I did later - =
I would have discovered the problem.  Seems like the one side of the =
screen supply power transformer goes to pin 4 in the early serial number =
30K-1 and pin 5 in the later serial number 30K-1 that I own.

Lesson:  We know that there were numerous manual editions for later =
Collins like the 75A-4 and KWM-2's.  But I never thought that there =
could be more than one edition for the 30K-1. Incidentally, the two =
manuals look identical with no reference to dates.  =20

Remember to make sure that the schematic/manual edition matches the =
radio.  When you buy a Collins always determine if the manual is the one =
that came with the radio or was the manual from an earlier or later =
radio.  On some of my 75A-4 manuals, I noticed that the original owner =
penciled in the serial number inside the front cover - which is good =
idea when servicing the radio.=20

By the way,  have you noticed the new additions to the CRA website =
homepage at the bottom left with reference to QTH.NET and the December, =
2002, Collins Album section?

Thanks.

David Knepper - W3ST
Secretary to the Collins Radio Association (CRA)
Publisher of the Collins Journal
www.collinsra.com
CRA station call - W3CRA


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