The PHILCO Phorum
37-620 Inner chassis - Printable Version

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37-620 Inner chassis - John_S - 05-30-2013

The 37-620 appears to have a floating inner chassis. Is this supposed to be electrical isolated from the outer chassis? This radio works when the inner chassis is in one position but when it is moved it stops.

Any help is appreciated.

RE: 37-620 Inner chassis - Phlogiston - 05-30-2013

No. It is on rubber mounts, but it is not isolated. As a matter of fact your problem may be that you are loosing the ground.

RE: 37-620 Inner chassis - John_S - 05-30-2013

Thanks for the reply, is the grounding through inner chassis metal to outer chassis metal or is the there a bonding strap that is missing on this radio?

Thanks Again

RE: 37-620 Inner chassis - morzh - 05-30-2013

See if there's maybe a wide mesh wire or something delivering the Ground to that inner chassis through some bolt that say is a bolt holding the tuning cap or something. This is the case in 18.

Also buzz the ground - buzz the two chassis, see if there is conductivity or a lack of thereof. And then simply connect them with a wire and see if that makes it work. !!!! Do not hold the wire and the chassis with both hands.!!!

RE: 37-620 Inner chassis - BrendaAnnD - 05-30-2013

When working with voltages over 70 volts, always try to keep one hand in your pocket. Icon_smile

RE: 37-620 Inner chassis - morzh - 05-30-2013

Well, here's of hands, pockets and high voltages.

http://screen.yahoo.com/electrical-workers-play-power-lines-113848405.html

RE: 37-620 Inner chassis - Ron Ramirez - 05-31-2013

Or, one of those wires running between the RF unit and the main chassis may be intermittently shorting to ground. Cloth-covered wire goes bad, too. I've noticed it is especially prone to drying out and losing insulation in those 1937 models.

RE: 37-620 Inner chassis - morzh - 05-31-2013

Many of those are good 'till you bend them. While restoring 38-15 I noticed that while none of the appears frayed if you have to bend it, it will crack. This was the reason I replaced a few of them.