[Hammarlund] Old Hammarlunds - modifications.

[Richard Knoppow]

----- Original Message ----- 
From: "Kenneth G. Gordon" <kgordon2006 at frontier.com>
To: <Hammarlund at mailman.qth.net>
Sent: Thursday, April 14, 2011 9:00 AM
Subject: [Hammarlund] Old Hammarlunds - modifications.


>A kind soul on this list sent me zipped copies of three 
>articles from CQ
> magazine detailing modifications to the Super Pro. These 
> are the Geissler
> article from 1957, the Lee article from 1958, and the Reed 
> article from 1961.
>
> ALL of these are rather extensive, and NONE of them seem 
> to me to be
> totally necessary.
>
> Some time back, I bought two BC-779s from one of our list 
> members, one of
> which is obviously the victim of the CQ magazine article 
> entitled, "The
> Ultimate Conversion of the Super Pro" by Reed.
>
> The complete audio system was removed, part of the chassis 
> was hack-
> sawed out, and a power-supply and a completely different 
> audio system built
> in in place of the original audio system, miniature tubes 
> were substituted for
> many of the octals, etc.
>
> I have not yet examined the receiver closely enough to 
> tell how far the
> original owner went with the modifications, but it looks 
> very extensive. The
> job also appears to have been well done.
>
> The OTHER BC-779 included in the package appears to be 
> completely stock
> and untouched. It even has its original power supply, also 
> untouched.
>
> After I restore that one, it will be interesting to 
> compare their operation.
>
> Lastly, I have a third BC-779, which is in rather poor 
> condition, which one of
> my nephews found in Butte, Montana and got for me from an 
> estate. It
> includes a cabinet, the only one I have, although the 
> cabinet MAY not be the
> correct one.
>
> I have not yet decided what to do with that one: either I 
> will attempt a limited
> restoration, or, if it is bad enough, use it for parts.
>
> I'll keep the list informed, for those who might be 
> interested, although it will
> be some time before I am going to be able to get to them.
>
> Ken Gordon W7EKB

    The Geissler article sounds familiar but I think the one 
I mentioned was earlier. This article changed the RF and 
mixer to dual triodes and changed the audio amp from triode 
connection to pentode connection with feedback. I don't 
think these are good mods. The only mod I suggest is adding 
a VR tube for the LO. In general, I don't like wholesale 
modification.

--
Richard Knoppow
Los Angeles
WB6KBL
dickburk at ix.netcom.com