BTW, I wonder if anyone out there has had experience
with the Hallicrafters version of the SP-600? I am curious
how its performance compares with the original.


If my info infers what I believe it does, the R-274 (nee SX-73) was the
first of the line. The Hammarlund SP-600/R-274( ) came later as they
beat out Hallicrafters for the follow-on contracts. I have both
receivers but prefer the Hallicrafters. Tuning is much smoother and the
SX-73 has all the normal features of a general coverage receiver. I do
not, however, have a clue as how they stack up regarding responses. I
have heard rumors that there was a Hallicrafters R-274 "B" version of
but the contract number is the same as the "original" R-274. I suspect
this was merely a simple production change of a couple of components
(capacitors) rather that a substantive design change.
de K3HVG