"Dan" wrote in message
...
On Mon, 14 Jun 2004 20:59:25 GMT, Aaron Burr
wrote:

Out of curiosity, has anyone built a homebrew version of the SRIII?
I suppose with the addition of a calibrated tuning scale, and maybe
a few other improvements here and there, it will be a very good AM DX
machine. Doesn't it use a variable inductor for tuning?

Kinda related to this, but I've always wondered: which version of the
SR is the best? I, II, III? What are the differences? Which one
would *you* want and why?



As for 'best', there are differing opinions. As for most technically
functional, the SRII is the best. It and the SRI are nearly identical
electronically, but the addition of the tweeter makes for marginally better
audio on FM.

The SRIII's only real claims to fame are the fact it has a wideband mode and
Xband on AM. The dial calibration and the QC are atrocious.

All three are 'long range' types, with a tuned RF stage after the antenna
stage. The SRI was by far the sturdiest built, with a metal power switch
and large tuning cap. The SRII went to a plastic switch, a smaller tuner
cap, and added the tweeter. The SRIII got rid of the tuning cap altogether
and went with varactor tuning, the 'tuner' is a breakdown prone
potentiometer. Aligning/calibrating the SRI/II is pretty straigtforward.
Doing so on the III is problematic at best, impossible at worst. That being
said, if you happen to get a good SRIII, they make a fine DX radio.. problem
is, you only have about a one in 5 chance of getting one that's 100% up to
spec (calibration is off on almost all of them. Some it's off up to 100KHz
on AM, and up to 2MHz on FM).