12-25-2017, 11:10 PM
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Haven't gotten to the power supply yet on this. Have been battling a stubborn chassis.
As mentioned in the thread about adding an A supply to a B power supply, I found the primary of the OSC coil was open. I replaced it with one of the P-70-OSC coils from the Antique Radio Supply but I could not pull in stations. I then found a winding open on the ANT coil as well, so I replaced that with the P-70-A coil from AES. It receives stations now but the bandwidth is quite a bit off. I get 620 AM with the rotor about half way out of the stator on the tuning capacitor, when it should only be out about an 1/4 at most. I tried aligning it but was only able to move the station back a short way before I ran out of screw (the adjusting screw on the tuning cap is backed out all the way). I can get our other strong local station at 1470 and that seems pretty close to where it should be.
Is it just that that replacement OSC coil may not be close enough to the resistance values / number of windings on the original coil to be compatible? Does anyone have any ideas on what I can try doing to move the lower end of the dial back to where it should be?
Haven't gotten to the power supply yet on this. Have been battling a stubborn chassis.
As mentioned in the thread about adding an A supply to a B power supply, I found the primary of the OSC coil was open. I replaced it with one of the P-70-OSC coils from the Antique Radio Supply but I could not pull in stations. I then found a winding open on the ANT coil as well, so I replaced that with the P-70-A coil from AES. It receives stations now but the bandwidth is quite a bit off. I get 620 AM with the rotor about half way out of the stator on the tuning capacitor, when it should only be out about an 1/4 at most. I tried aligning it but was only able to move the station back a short way before I ran out of screw (the adjusting screw on the tuning cap is backed out all the way). I can get our other strong local station at 1470 and that seems pretty close to where it should be.
Is it just that that replacement OSC coil may not be close enough to the resistance values / number of windings on the original coil to be compatible? Does anyone have any ideas on what I can try doing to move the lower end of the dial back to where it should be?
Greg V.
West Bend, WI
Member WARCI.org
