04-08-2008, 07:45 PM
I found the answer to my own question, lol! I spent some time on that RF coil today. I found the bottom turn (B+ side) was open. I was able to repair it by soldering it back together. 
Now, as far as the performance of the radio is concerned, I noticed no difference in sensitivity or performance with the coil operating properly. I was still able to receive 740 AM Toronto in the day time on my outside wire antenna. It was the same relative signal that I had before I repaired the coil. In this case, since the open was near the bottom end of the primary, there were lots of turns available to provide sufficient coupling for the signal to transfer to the secondary. Others may not be so lucky, depending on where the break is. However, I would try that shunt feed idea again.
Regards,
Ed
Now, as far as the performance of the radio is concerned, I noticed no difference in sensitivity or performance with the coil operating properly. I was still able to receive 740 AM Toronto in the day time on my outside wire antenna. It was the same relative signal that I had before I repaired the coil. In this case, since the open was near the bottom end of the primary, there were lots of turns available to provide sufficient coupling for the signal to transfer to the secondary. Others may not be so lucky, depending on where the break is. However, I would try that shunt feed idea again.
Regards,
Ed
