06-09-2020, 04:15 PM
I have a Philco Model 118 restored and playing great but I have no shadow meter vane action. I took the lens off and can see the vane. With the radio off the vane is facing the front (narrow side). I can move it with a toothpick and it appears to be spring loaded with the narrow side facing out as its rest position. Is that right?
The part number is 2028 and it measures 1437 ohms so the coil is not open. The schematic indicates a 2900 ohm shunt but the as found one installed measures 1200 ohms. I have experimented with various shunt values (0 to 7K ohms) and there is no affect. No vane action ever. Shouldn't the vane show its wide side (maximum shadow with the radio off, i.e. no station tuned in? And what does it take to move the vane to the narrow position--more current or less current?
When I measure the voltage across the meter I get minimum voltage (and hence minimum current) on a strong station and a larger voltage (and hence larger current) when off station. Does anyone know what the ma range is supposed to be, i.e. how much current to get the vane to move to cast a wide shadow vs. how much current to get the vane to face the front and cast a narrow shadow?
How do I fix this thing or do I need to look for a replacement? Maybe the vane is getting stuck on its pivot. My next step will be disassemble it to see what is going on inside.
Here is the schematic:
http://www.nostalgiaair.org/pagesbymodel...013125.pdf
Thanks,
Joe
The part number is 2028 and it measures 1437 ohms so the coil is not open. The schematic indicates a 2900 ohm shunt but the as found one installed measures 1200 ohms. I have experimented with various shunt values (0 to 7K ohms) and there is no affect. No vane action ever. Shouldn't the vane show its wide side (maximum shadow with the radio off, i.e. no station tuned in? And what does it take to move the vane to the narrow position--more current or less current?
When I measure the voltage across the meter I get minimum voltage (and hence minimum current) on a strong station and a larger voltage (and hence larger current) when off station. Does anyone know what the ma range is supposed to be, i.e. how much current to get the vane to move to cast a wide shadow vs. how much current to get the vane to face the front and cast a narrow shadow?
How do I fix this thing or do I need to look for a replacement? Maybe the vane is getting stuck on its pivot. My next step will be disassemble it to see what is going on inside.
Here is the schematic:
http://www.nostalgiaair.org/pagesbymodel...013125.pdf
Thanks,
Joe
