[Hammarlund] sp600 for ham work?

[Grant Youngman]

Wellllll ...  

It won't change the basic issues with the receiver.  Don't get me wrong, my
SP-600 was my first boatanchor project and remains one of my favorite
radios.  For AM it's terrific anywhere in its tuning range, for SSB/CW it
will be ok up through 40 meters.  Above 40, as others have said, you run
into several problems -- tuning rate, and to some degree overall stability.
As far as selectivity is concerned, it isn't a match for a radio with a
50-60Khz LC IF or crystal (or even ceramic) filters, and in really crowded
ham band conditions it collapses pretty easily.  

For SSB, I've used an internal product detector (didn't like it and removed
it), A C-E sideband slicer (great audio!), Hammarlund HC-10, and most
recently a Sherwood sync detector for both AM and SSB. 

That being said, the first receiver I had as a Novice in 1959 was a
broad-as-a-barn BC-455, and I had a lot of big-time fun with it before my
"major" upgrade to a BC-312N :-)

For general purpose ham use, I think you'd be better off looking at either
your HQ-129 or HQ-140X if they're servicable -- both are excellent receivers
with ham band calibration and crystal filters.  They will also suffer from
stability (and possibly sensitivity) issues on the higher ham bands, but I
think they'd be a better choice as a starting point.  I think I'd go with
the 140X first ... it was the receiver we used at my high-school radio club,
and is a good radio.  It has the same IF frequency as the SP-600, so the
same SSB detector solutions will work on these radios, too.

Grant/NQ5T


> Ed, thanks for the advice. One question. I recently purchased 
> a product from Almost all digital electronics as a frequency 
> readout for the SP600. My version of this has the blue vacuum 
> florescent disaply. I believe it is accurate to 100Hz.  If I 
> were to employ this device, do you think it would be better 
> suited?