[Boatanchors] What Are the Differences Between Input, Interstage, Output IF Transformers?

[Donald Chester]

Just what it says.  The input transformer feeds the first i.f. stage, following the mixer/converter stage.  The interstage transformer is the coupling transformer between two i.f. stages.  The output transformer follows the final i.f. stage and feeds the detector.

The "tweet filter" in the front end of the Collins 75A-4 is tuned to a specific fixed frequency in the low end of the 80m ham band, to attenuate a spurious carrier that appears on that frequency, a harmonic (or image frequency thereof), of the 1st conversion stage crystal oscillator. Its function and adjustment procedure are fully described in the manual.

Don k4kyv.