[Boatanchors] Help re the ORIGINAL Hammarlund Four-Twenty Transmitter

[williamhf]

  The Hammarlund Four-Twenty Transmitter manufactured only during 1947 
and 1948
seems to be fairly scarce among Boatanchor afficionados.

 I acquired one recently. (I built the xmtr from a Kit in 1948; traded 
it in a year or so later.)

I'm getting older now and everyone knows that old folk's memory banks 
are kinda worn
and there's a certain amount of slippage.

But here's my memory of how the Final Tank Coil was tuned to the Antenna 
output terminals.
My memory says that there was an *_/ADJUSTABLE/_* LINK in the middle of 
the Final Tank Coil.

I have what seem to me to be fairly crisp memories of removing the top 
cover and adjusting
the Link in, or, out to get more power to the Antenna output terminals. 
I used a $4.95 Amphenol Folded Dipole
Antenna on 10 Meters and it was the only Coil for the four ham bands the 
Four-Twenty covered.

Recently, I have "pinged" for 5-pin RF TankCoils on "Boatanchors" and 
the Hammarlund Reflector and
happily have acquired some B&W MEL and JEL 5 pin coils.  Now please 
understand that I
have not yet got the Four-Twenty refurbished/rehabilitated but and am 
working along on that project.

But all these JEL and MEL  coils have either end or center  *_/FIXED 
/_*output links.

Why am I writing to Boatanchors? I seek to learn if there's anyone among 
the Boatanchor
ranks who happens to own a Hammarlund Four-Twenty Transmitter in_* 
ORIGINAL*_
condition?
And/OR-------------Is there a ham out there who may not own the 
transmitter but is confident
that he knows how the Antenna terminals were coupled to the Final Tank Coil.

Here's a direct quotation from the Hammarlund Four-Twenty Owner's Manual:
/*"Plug-in Coils are used in the Output Circuit of the Powr Amplifier.
These plug-in coils are accessible by removing the top cover of the 
transmitter and are
 equipped with an output coupling arrangement with an adjustable tap to 
permit matching
the output of the transmitter to any of the conventionally used antenna 
feeder systems."

*/Doesn't that Quote make one feel scure and certain that somehow when 
you reached inside the top
cover you could move something which affected the coupling of the Final 
Amplifier circuit to
the Antenaa Output terminals?

Two current owners of the Hammarlund Four-Twenty that I have contacted use
FIXED LINKS in their RF output circuitry.

I am convinced that there was an adjustable link furnished by Hammarlund 
in the ORIGINAL
Four-Twenty Transmitter.
/*
*/*E*xamination of the 4-20 Schematic shows a peculiar symbol (to me) 
for the output link of
the Final Tank Coil System. (I don't know a simple way to reproduce it here)
Whereas the Final tank coil itself is shown connected to two definite 
points, the Link
is  connected to two definite points which are the Antenna Input 
Terminals- BUT, BUT
The link has an extra partial "loop" which is shown on the Schematic as 
just free-ended,
that is, not fixed to a connecting point. The Electronics Draftsman was 
showing
a different-than-conventional Link symbol.

The Photograph at RigPix      http://www.rigpix.com/hammarlund/four20.htm
 shows an upper central  front panel control marked  "Amplifier Tuning"
but it controls the variable capacitor shunted across the  Final Tank 
Coil, not a Link coil.

Any help or clues will be greatly appreciated. Thanks, guys.

Bill
W4DSR
Florida