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Another model 60 antenna coil question
#1

After restoring my model 60 chassis and powering it up there is no RF reception but the IF's tune up properly. I determined that the antenna coil has problems. It appears that this chassis was hit by lightening some time in the past and a patch job was done to repair it.  The wavetrap was gone and bypassed, with just a burn mark left on the chassis and the antenna coil ohms out shorted to ground on the secondary. 

I took the coil apart and determined that the secondary is good but the primary which is the small universal winding at the top of the coil was mis-wired.  The inside of the shield can and the inside of the coil form were charred which means that they were burnt out and replaced and the replacement was mis-wired, as one lead was connected to the start of the secondary. 

I removed the primary coil and it seems to read correctly but although the lead to the antenna is the finish and the start wire goes to ground, there is a tap on the coil that appears to be the junction of the 11 ohm coil and the 0.7 ohm coil.  The 0.7 ohm coil section appears to connect between the antenna and the tap, not the correct way it is shown in the schematic.

I have searched through the forum but still have not come up with a definitive answer as to how this coil should be connected.  From reading the search posts there might be another primary of 4? turns on the main coil form but I cannot find it on mine.  Wondering if the replacement primary was the correct one?  

Any help would be really appreciated. 

Thanks,

Steve D


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Another model 60 antenna coil question - by Steve D - 12-27-2015, 08:05 PM



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