RadioBanter - View Single Post - Cascaded Radios for Better Selectivity, Gain, AGC

October 17th 03, 08:22 PM

In article ,
says...
Haven't seen any discussion on this but lots on cascading filters. If
you have a radio with an IF output (or can modify it to get the IF
out) and a second radio that can receive the first one's IF, you can
cascade them for some amazing results. I did this with a pair of
DX-394's. You get sharper selectivity on AM due to the cascading of
filters, continuously variable selectivity by tuning RX1 off frequency
and RX2 off RX1's IF, extra gain to pull up the weak ones into the
incredible AGC range. With 5kHz steps, tuning across the SWBC bands is
like changing channels on a TV set.

"snip" Us old farts call this a "Q-5 er" Did this once
with a navy surplus 3 bander which had a 75khz IF intended for about 700
hrz bandwidth for cw in LW, tuned the front end to 455 and tapped into
the last IF stage of my SX-28. The accumulated 60 hz hum made it an ear
breaker, but if I really wanted to pull weak cw on 80 meters out of a
net there was all the gain I could use.