12-16-2013, 06:56 AM
Bret;
As a general rule when doing alignment of radios, adjust the inductor (if adjustable) for the low frequency end of the dial and adjust trimmer capacitors to get the top end of the dial, especially the oscillator circuit. Inductors in the RF amp circuit will peak the signal strength on the low frequency end of the dial and trimmers will peak the signal strength on the high end of the dial. If you hit a band that does not want to allow the trimmer capacitor to tune high enough it indicates that there is somehow too much capacitance for the circuit to tune that region. Some sets actually had instructions to the alignment requiring a technician to compress coil windings to peak the low frequency end of the dial and hand select fixed capacitors to allow trimmers to handle the high end of the dial. I notice there are two twisted wires on the bandswitch section to the left. This may be a gimmick capacitor or an inductance that was added to trim one band, although I can't tell which band would be affected.
Your 41-315X bandswitch and coil assembly looks similar to my 40-201, but has significant differences too. At least your set uses replacable mica capacitors in the front end. My 40-201 has some capacitors made with metal plates and mica sandwiched between them and a rivet holding them together! Those may be problematic if corrosion ever starts there. I wonder about the penetration of moisture. Of course trimmer capacitors always have that issue over time and you might want to examine them closely to see if there is corrosion of the metal surfaces that hold the mica in compression.
Joe
As a general rule when doing alignment of radios, adjust the inductor (if adjustable) for the low frequency end of the dial and adjust trimmer capacitors to get the top end of the dial, especially the oscillator circuit. Inductors in the RF amp circuit will peak the signal strength on the low frequency end of the dial and trimmers will peak the signal strength on the high end of the dial. If you hit a band that does not want to allow the trimmer capacitor to tune high enough it indicates that there is somehow too much capacitance for the circuit to tune that region. Some sets actually had instructions to the alignment requiring a technician to compress coil windings to peak the low frequency end of the dial and hand select fixed capacitors to allow trimmers to handle the high end of the dial. I notice there are two twisted wires on the bandswitch section to the left. This may be a gimmick capacitor or an inductance that was added to trim one band, although I can't tell which band would be affected.
Your 41-315X bandswitch and coil assembly looks similar to my 40-201, but has significant differences too. At least your set uses replacable mica capacitors in the front end. My 40-201 has some capacitors made with metal plates and mica sandwiched between them and a rivet holding them together! Those may be problematic if corrosion ever starts there. I wonder about the penetration of moisture. Of course trimmer capacitors always have that issue over time and you might want to examine them closely to see if there is corrosion of the metal surfaces that hold the mica in compression.
Joe
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