Ts18 chassis Motorola

[Electronic M]

One thing that comes to mind: you put a new diode in parallel with the original detector (which confirms it ain't open), but did you test the resistance of the old diode both directions to confirm it is not shorted?

If it's shorted it could explain both symptoms you have.

Tuning RF/IF coils should always wait until it's last resort time, and all components have been tested.

[old_coot88]

Originally Posted by Electronic M

Tuning RF/IF coils should always wait until it's last resort time, and all components have been tested.

And even then, turning of the video IFs should never happen unless one is equipped with a sweep genny and 'scope and knows how to do alignment, AND there's clear-cut evidence of misalignment (ringing and/or smearing of fine detail in the pic), and subbing the IF tubes doesn't fix it.

[Electronic M]

Originally Posted by old_coot88

And even then, turning of the video IFs should never happen unless one is equipped with a sweep genny and 'scope and knows how to do alignment, AND there's clear-cut evidence of misalignment (ringing and/or smearing of fine detail in the pic), and subbing the IF tubes doesn't fix it.

Agreed. Though some service prints give data for a sweep-less peaking alignment using a simple sine-wave generator, some adjustments like traps are meant to be peaked to a frequency and can be set the same way.

I remember one guy here who properly aligned a Dumont by eye....I would not try or recomend that, but MAN was it ever impressive....