Tony Giacometti wrote in
news:suednRqSYJd58aLanZ2dnUVZ_uDinZ2d@hawaiiantel. net:

also, if these loops don't work then why do these designs exist?

Tony,

A few questions:

1. With a 50 load on the preamp input, when tuned to a quiet spot in the
band, RF gain full, preamps on, telephony bandwidth, does the S meter
deflect at all?

2. If no s meter deflection, note the receiver audio output voltage.

3. With the loop connected on the preamp input, when tuned to a quiet
spot in the band, RF gain full, preamps on, telephony bandwidth, does the
S meter deflect at all?

4. If no s meter deflection, note the receiver audio output voltage.

5. What is the ratio of the voltage at 4 to the voltage at 3? If it is
more than about 3:1, you have achieved nearly as good a S/N ratio as is
possible.

Owen