The PHILCO Phorum

Full Version: 37-675 Bandswitch
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I picked up a 37-675 that was listed on the sell forum for free a few weeks ago. Pete in NJ did a lots of work on the set along replacing all the caps, some micas, and about half of all of the resistors the cabinet is simply beautiful with it's original finish. It plays well but is doa on the SW bands. After doing a bit of troubleshooting there seems to be a problem near the band switch. Osc and mixer are working fine but I'm not getting any signal from the plate of the RF amp. Will work if I hook the ant to the grid of the mixer tube. If I connect the ant to the plate pin of the RF amp though a coupling cap I get no signal. In the broadcast and SW positions volts look good around the RF amp.
The big question is if I remove the RF sub chaiss will that give me good access to the bandswitch wafers? Looking with sub chaiss in place it looks like there's still a lot of parts in the way of the wafer.
Tnx
Terry
Very Nice set!! Well worth the 3hrs in the car and he's a nice guy!!
http://www.flickr.com/photos/42774321@N08/4965055790/
Man that is one nice looking set. Looks show room. And for free . I will give you free dollars for it. Icon_lol
Kent.
Hi Terry

You're right...that is a really nice radio! Looks like it has a new Mark Oppat dial scale, too.

In order to get to the band switch wafers, you will not only have to remove the RF unit, but once it is out, you'll have to disassemble it as well, removing the antenna section (back) and the RF section (middle) to be able to see - and service - everything.

You have to pull the shaft out before attempting to remove any of the sections of the RF unit. It is held on in front of the unit with two small bolts on a flange. Note that the shaft is indexed, so that it can be inserted only one way without damaging the wafer sections.

Removing and disassembling the RF unit is not as difficult as it sounds, but is definitely not an easy job.

For what it's worth, I once had a 37-something Philco that would not work. The problem turned out to be an arcing wafer switch section. I managed to cut away the burned part, and fill the crevice with epoxy. Worked fine afterwards. I was, quite frankly, amazed that that sort of damage could be repaired.

Good luck.
That set is sweet!