08-20-2014, 12:52 PM
Yeah, that was my first thought. I measured lug to lug across the primary and the secondary, and it seems to be intact. I measured all the resistors connected to the 6A7, and they were all within 10-20% of correct. I changed out C46 & R45 because they looked a bit sketchy. R10 is spot on, and R15 is a 30K instead of 32K. R47 is 39K instead of 37K. C12 is tubular instead of mica, but the value is correct.
I'm starting to wonder more about the trimmers. I've never had a set with bad trimmers before, so I don't really know what to look for there. They measure some resistance in each of the IF trimmers (17, 19, 22, and 24), but they could be dirty, or intermittent. I can see some of the mica looks a bit ragged, and I have a memory of seeing some mica flakes when I first got the set over a year ago, and the wave trap was a dead short, so I by-passed it. The antenna now connects directly to the band switch. I have some mica sheets that are about the right thickness and cut quite easily. I wonder if it is possible to rebuild this type trimmer (they are riveted at the bottom and have metal leaves separated by mica sheets).
The ones on the tuning cap: one looks in good shape (11) and the other (7) looks a bit ragged and loose in its frame.
The other thing I wonder about is the band switch. It moves like it should, and has a solid click to it, but could be cleaner, I suppose. Also, I am a bit muddled on reading the schematic there. I read six different switches (one has three contacts), and I'm sure about which is which on the set, but I'm less sure about the switch where the antenna connects to the band switch and R3. The antenna coil has a lug on its top and 6 around the bottom including the grounded lug. The way I read it, the lug up top is lug one and the lug to the right of the grounded lug (looking from under the chassis) is lug two. If that is right, then I have the band switch connected correctly. The antenna coil measures out good, too.
I'm starting to wonder more about the trimmers. I've never had a set with bad trimmers before, so I don't really know what to look for there. They measure some resistance in each of the IF trimmers (17, 19, 22, and 24), but they could be dirty, or intermittent. I can see some of the mica looks a bit ragged, and I have a memory of seeing some mica flakes when I first got the set over a year ago, and the wave trap was a dead short, so I by-passed it. The antenna now connects directly to the band switch. I have some mica sheets that are about the right thickness and cut quite easily. I wonder if it is possible to rebuild this type trimmer (they are riveted at the bottom and have metal leaves separated by mica sheets).
The ones on the tuning cap: one looks in good shape (11) and the other (7) looks a bit ragged and loose in its frame.
The other thing I wonder about is the band switch. It moves like it should, and has a solid click to it, but could be cleaner, I suppose. Also, I am a bit muddled on reading the schematic there. I read six different switches (one has three contacts), and I'm sure about which is which on the set, but I'm less sure about the switch where the antenna connects to the band switch and R3. The antenna coil has a lug on its top and 6 around the bottom including the grounded lug. The way I read it, the lug up top is lug one and the lug to the right of the grounded lug (looking from under the chassis) is lug two. If that is right, then I have the band switch connected correctly. The antenna coil measures out good, too.
Charlie in San Antonio