[georgetownjohn]

Thanks for the info Greg.  I have bought a 37-620 non-working chassis in the hopes that I can use parts of the RF unit/bandswitch for my 37-640.  The reason I think it might  be possible is because the tuner front bracket of my 37-640 has 37-620 stamped on it from the factory. ---John

[Greg]

Replacing that one section of the band switch makes sense. Just make sure the two have the same connections, though I can't imagine they don't match.

I have a 620 I'm working on and a 630 I got for parts. I noticed that the 2 band switches differed a bit in that one or the other has spare lugs (not connected via the switch) that were used for to connect stuff. 620 had a bad BC band antenna coil which I replaced with the one from the 630.

Otherwise, the two radio's (630/620) schematics look identical with the exception of the 620 having a 10K resistor where the 630 has a shadow meter.

[georgetownjohn]

Thanks Greg, your reassurance of using parts from the 620 is very helpful.  Since I am still new at all this, I will wait til the 620 chassis arrives before I start taking the 640 RF unit out and apart.  I still have the wires in the 640 labeled/numbered from the original restoration attempt so I am hoping the wiring layout is similar in the 620.  If I remember correctly, while taking the 640 RF/tuner section apart for the recapping, there are 3 divided sections similar to bulkheads on a ship.  The dividers are L shaped at the top and screw up into the top of the chassis.  If I am lucky, I will try to just remove the divided section that has the bandswitch and recap any caps in that section while I am at it.  Regards to all, --John
I do have 2 additional questions that you may be able to help with.
First, why does the 620 onl show 3 wires to the speaker while the 640 uses 4 wires.  Does it have anything to do with the fact that the 640 has push-pull amplificaton and the 620 does not? 
Second, I have read where Philco was notorious for making errors in part numbers.  So I wonder if I can still use the tuning capacitor from my 640 regardless of the bandswich I will use.  The front of my 640 tuner bracket capacacitor has 640 stamped on it from the factory but the part numbers for the tuner are different for the 620 vs the 640 in the respective parts lits!

[georgetownjohn]

This is a correction from last post about tuner capacitor.
The front of my 640 tuner bracket is factory stamped with 37-620 not 37-640

[Greg]

Oops, I for some reason I got it in to my head that you have 630, not a 640. None the less the front end of the 640/620 look the same.

Yes, looks to me like the push pull does give you an extra connection. Maybe this is too simple of a way of looking at it, but if you were to eliminate the bottom half of the output transformer it looks like the 620/630.

[georgetownjohn]

Thanks Greg, I think things may work out.  I will update as I start the work again when the 620 arrives---John