[Collins] R388 51j-3

[Dr. Gerald N. Johnson, electrical engineer]

The RF stage and mixers should set the receiver sensitivity no matter
what the IF gain. A weak tube in any of those stages including their
oscillator inputs could result in poorer sensitivity. I think the
difference in sensitivity is more one of alignment and calibration.

When listening to the wide open J-3, there will be more noise coming out
without signal than there will be with the J-4, simply because the wider
IF bandwidth of the J-3 passes more noise power than the widest
mechanical filter in the J-4.

73, Jerry, K0CQ, Technical Advisor to the CRA
-- 
Entire content copyright Dr. Gerald N. Johnson, electrical engineer.
Reproduction by permission only.