Good luck with your find! I have one and enjoy it, very much. The SX-73
was the first in the R-274 line. Hammarlund beat them out with the
SP-600, as you already know. Hallicrafters must have been in a hurry on
that contract. There are some curious design items and the tech manual
has some errors in matching diagrams with text, so look for that. Looks
like nobody did the proof-reading. My R-274 came with the original covers
and tools but someone had removed the dial brake. Too bad, too, it sort
of mucks up the front panel. I did a bit of re-capping, but it wasn't as
bad as some rx's of the same vintage. Alignment is not too difficult.
The light bulbs on the chassis are for ballast/regulation... not trouble
shooting lights....hi!! The band-switch turret can be a bear to work on
and are prone to break. Unlike the SP-600 (R-274B, etc.), the turret
design on the SX-73 is not robust, so to speak. The contact fingers are
quite delicate.. so be mindful of bending them, too. The tuning gears may
need cleaning and adjusting. The tuning knob should be free and be able
to spin, just bit, when its in good working order. Books are easy to find
and you will need one, absolutely. Hopefully, also, your unit will have
the original S-meter. There was a Signal Corps replacement for it (black
face) that can be found. Regarding the S-meter, read the fine print in
the manual. Unlike most other receivers, the s-meter in the SX-73 cannot
be zeroed. One sets the meter for a known input level. When no signal is
present, on a quiet band, the meter will negatively pin and, then, move
upscale with signals present. The book makes notice of this fact, so
don't try and make it zero. The power connector is an older style
2-prong, recessed male ac plug.
That's about all I can think of, at this time. Regards and, again, good
fortune with your unit. de K3HVG

John Morris wrote:

Want to talk with people who have this receiver. I will be getting one
in the next 30 days and would like to know the in's and out's of it.
Its oddities and known problems.

I've had several SP-600's and this, of course, was made to fulfill the
same government spec.(R-274) Although they are similar, I've read that
there are many differences also.

Thanks

John - K7RLD

www.qsl.net/k7rld