[Hammarlund] Old Hammarlunds - modifications.

[Todd, KA1KAQ]

On Thu, Apr 14, 2011 at 12:00 PM, Kenneth G. Gordon
<kgordon2006 at frontier.com> wrote:
> 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.


I think the time in which these articles appear indicate more about
the mods than anything. Back then, not many hams had a choice of the
plethora of gear we have today and instead had to make do with
whatever would fit their budget. There were a lot of surplus Super
Pros kicking around along with the BC-348, Command set/ARC-5s, and so
on. Wasn't around until the newest article was published, so I can't
say for sure but my guess would be that you did whatever you could to
upgrade/improve whatever you already had or could afford to buy.

Referring back to Henry Rogers' page on the Super Pros under
'Modification Mayhem', a number of these modifications seem to address
problems that were related more to user issues than actual design
deficiencies, or desires to somehow make a late 1930s radio into a
newer set:

"L. E. Geisler Modifications - With the cheap, easy to find
availability of the surplus WWII Super-Pro receivers in the
mid-fifties and sixties, the "modification mania" did finally catch up
with the line and the WWII Super-Pro was considered "fair game" for
modifications. Most of the infamous Super-Pro modifications were
derived from the first of the series, "Souping the Super Pro" by L.E.
Geisler, published in the Dec.1957 issue of CQ magazine. Geisler was
an engineer that worked out of Japan for a company that sold modified
Super-Pro receivers. Today, Geisler's modifications are "tame" and
basically replace the 6L7 mixer tube with a different octal mixer tube
that is quieter, then he replaces all of the capacitors and does a
full alignment - pretty much standard stuff. Geisler's mods are
conservative, make sense, improve performance and do no real harm to
the receiver. One has to remember that Geisler's company sold these
modified Super-Pro receivers so they had to perform better yet still
retain the professional-commercial appearance in order to have
marketability.

Post-Geisler Modifications - The later modification articles
endeavored to "out-do" Geisler's "makes sense" conservative approach
with more and more outrageous modifications. Included in the list of
notorious "cut and hack" articles are "A Super 'Super-Pro'" and
"SSBing the Super Pro" - both published in the "Surplus Conversion
Handbook," part of the CQ Technical Series. These articles advocate
the wholesale modification (destruction) of the entire receiver,
including replacement of the front-end tubes with miniature tubes, an
on-board solid-state power supply, removal of the 14 watt P-P audio
section to install an anemic 6AQ5 single ended audio section (which
also then provided room for the on-board power supply,) on-board
converters to cover 10 and 15 meters, product and infinite impedance
detectors - on and on. It's doubtful that a receiver could ever be
returned to original after being the victim of these later
modifications. I have only seen a couple of Super-Pros that attempted
these modifications and they were wrecks. No doubt, the end product
failed to impress the owners and the receivers were afterward
relegated to the junk pile."


While it probably made sense at the time, in today's world with so
many 'better' options(if that's one one seeks) available with new
sets, it seems like a lesson in futility. But since there are already
so many hacked up versions out there, we have plenty of opportunity to
investigate that side, too.

I sold one of these sets years ago that had every octal replaced with
miniature tubes. It looked like an empty box. A fellow in MA has
converted one to all solid state devices. It looks even worse! I
currently have two pre-war SX models which have both been hacked to
some extent. I'm hoping to restore at least one of them back to all
octal tubes, replace the other bad components, and go from there.
Unfortunately, it's never easy to figure out someone else's ideas
involved, especially when they never completed the mess!

The ones with the onboard power supply and hacked out audio are
horrendous. I always remind myself that it was someone else's radio
and I can't appreciate why they did it since I wasn't there. I try to
respect the role that surplus gear and amateur mods played in our
hobby decades ago, it's just that some of them seem to make so little
sense for the work involved.

~ Todd,  KA1KAQ/4