02-09-2022, 11:10 PM
Sorry misunderstood. The older s/m use a permanent magnet to center the vane and has some control over the sensitivity. Later models have a thumbscrew at the back to set the tension on the vane. These tend to be more sensitivity because you can lessen the drag used to center the vane and it can move more freely.
If you still have the resistor across the s/m that will diminish it's movement.
Good tubes, alignment, and a good long ant. It comes down to the avc voltage generated by the signal causing the change in plate current on the mixer and 1st IF amp tubes. If the signal is weak the s/m may not react as the avc has got the gain flat out and the tubes (mixer/ IF) aren't drawing enough current to make much of a difference on the meter.
If you still have the resistor across the s/m that will diminish it's movement.
Good tubes, alignment, and a good long ant. It comes down to the avc voltage generated by the signal causing the change in plate current on the mixer and 1st IF amp tubes. If the signal is weak the s/m may not react as the avc has got the gain flat out and the tubes (mixer/ IF) aren't drawing enough current to make much of a difference on the meter.
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
