The PHILCO Phorum
37-610 IF Cans - Printable Version

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37-610 IF Cans - Olskuul - 07-31-2015

Hi all! I've been doing a ground up restoration on a 37-610 tombstone and, despite loads of pictures and supporting documentation, I've encountered several gray areas. I have a code 121 or 122 chassis.  Can't really tell which, as the markings are long gone, but the rectifier tube sits on top of the transformer, so I think this is right. I also purchased a scrap chassis from Playthings in order to salvage some missing parts. This too was supposed to be the same code as mine, but there are many differences. Anyway I took tons of photos of the original chassis and then stripped it bare. Each part was then cleaned, restored or replaced. Now as I'm putting it all back together, I find that the IF cans aren't matching up with the schematic as far as their resistance values. It appears that their placement in the circuit should be swapped. Originally the 1st IF can was up front and had two small black leads along with the four coil leads, but the other can's values are almost exactly what the schematic calls for. Should I go against the original assembly and follow the schematic instead? And where do those two small black leads connect?  Unfortunately, they didn't show up in my pictures. The salvage chassis' IF cans turned out to be totally different. Their values don't match with the my Rider's schematic and they each have internally mounted resistors. There are other issues, but I'd appreciate some feedback to help me get through this one.  I can provide pictures if asked.  Thanks in advance.  

RE: 37-610 IF Cans - Olskuul - 09-07-2015

No suggestions? Surely someone out there has run across this situation.

RE: 37-610 IF Cans - klondike98 - 09-07-2015

Welcome to the Phorum!
You might find some documented changes in the file changes.zip.  Not all changes were documented.  I don't have a 37-610 though.  Nice work!!

RE: 37-610 IF Cans - Olskuul - 09-07-2015

(09-07-2015, 10:36 PM)klondike98 Wrote:  Welcome to the Phorum!
You might find some documented changes in the file changes.zip.  Not all changes were documented.  I don't have a 37-610 though.  Nice work!!

Thanks klondike98!  I need to complete the wiring, but hit a wall regarding these If cans.  Also thanks for the link.  Unfortunately, there was no reference to this issue.  I guess I'll go ahead and wire them in, then swap them to see which performs better.

RE: 37-610 IF Cans - klondike98 - 09-07-2015

I would put it back the way I found it, but others may gave other thoughts.

RE: 37-610 IF Cans - Bob Andersen - 09-08-2015

I recently worked on a 37-640 which had two small wires in the 1st IF can too. THey were not shown in the schematic but are mentioned in the production changes

"The first I.F. Transformer, Part No. 22-2274 has a stabilizing winding which is placed n series with the suppressor grid of the 6K7G I.F. tube"

It's drawn in on this schematic as the squiggle going up to ground.