12-01-2016, 07:12 PM
Sounds like your AVC voltage range might be a bit low if it only reaches -4.5V with a strong received signal.
I don't have a 16, but with a 118 with the same type shadow meter I routinely reach -12V on the detector output where the AVC is derived. This level is reached on local stations with a 10 foot wire antenna. At this AVC voltage the shadow reaches a minimum width of about 5 mm.
With only -4.5 V of AVC, the plate current of the IF tubes will not change much. They are of the remote cutoff type and it takes much more negative bias to reduce the plate current to the point where the vane will narrow the shadow.
I seem to remember my meter current changed from about 8 ma no signal to around 2 ma tuned to a strong station.
I don't have a 16, but with a 118 with the same type shadow meter I routinely reach -12V on the detector output where the AVC is derived. This level is reached on local stations with a 10 foot wire antenna. At this AVC voltage the shadow reaches a minimum width of about 5 mm.
With only -4.5 V of AVC, the plate current of the IF tubes will not change much. They are of the remote cutoff type and it takes much more negative bias to reduce the plate current to the point where the vane will narrow the shadow.
I seem to remember my meter current changed from about 8 ma no signal to around 2 ma tuned to a strong station.
