[AMRadio] Why I Chose A Globe King 500B

[Damon Raphael]

There were very few commercial rigs produced in the 500 W Plate Modulated AM
category.
The Johnson 500 covers the upper HF ham bands but not 160 meters and
commands a much higher price than the GK.
The Johnson KW Desk is a big monster which is way out of my price range.
The BC-610 weighs 400 to 450 pounds and covers 1 to 18 mHz.  It does not do
10 meters.
The T-368 weighs about 680 pounds and covers 1.5 mHz to 20 mHz.  It does not
do 10 meters.
I know that some folks have modified these rigs to cover the bands that thet
were not designed to do but I did not want to tackle that problem with the
big beasts.  Just removing and carrying the modules is a weight lifting
chore and should you fry a "big iron" component you are in deep #$@&*.  Not
to mention the firestorm that could arise from a "golden screwdriver " mod.
Both of the military transmitters require an external frequency control
device.  The T-368 uses a dedicated exciter which is an added expense and
maintenance problem.  I don't know if the T-3 can be used without that
specific device when XTAL controlled.
The Globe King 500B covers 160 through 10 meters and has a built in VFO.  It
weighs about 275 pounds.  It is quite a bit smaller in size and weight
compared to the military rigs.
While the BC-610 in it's various versions is a commonly available unit, a
T-368 for sale is much harder to find.
Broadcast transmitters are available but are very large units and are
difficult to run on more than one band.  To my knowledge, the commonly
available units would be difficult to run above the 40 meter band.
I started to scrounge for parts to build a 500 W rig but quickly gave up on
that.  Here in Arizona, there are very few swapmeets so major building parts
are hard to find.   You don't want to have to pay Peter Dahl or eBay prices
for that stuff.   If you have a shed full of old parts and "heavy iron" plus
the knowledge and experience needed to match up the component parameters and
if you have the tooling to do the metalwork, then homebrewing a big rig is
the way to go.
None of the above rigs have "good" audio as designed.  They all have to have
some modification to widen the frequency response to meet today's  standards
for ham use.
Given the above, I decided that the Globe King 500B was a reasonable value
at today's prices.

Damon Raphael, W7MD
Tucson, AZ