Philco 38-4 wire identification?? - Printable Version
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Philco 38-4 wire identification?? - CodyTerry - 10-15-2017
[attachment=14485]Can anyone tell me where this wire attaches under the chassis? I cannot identify it on the diagram. Thanks, Cody ?
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RE: Philco 38-4 wire identification?? - Radioroslyn - 10-15-2017
Where dose the connected end go?? Best guess is that it for the pilot lamps or the muting switch.
RE: Philco 38-4 wire identification?? - CodyTerry - 10-15-2017
It comes from the back of the dial...its riveted on. It attaches to the round plate directly behind the dial that when the knob is fully depressed, a contact is made from the back of the knob out through the wire in question. Muting switch perhaps? I'm learning!
RE: Philco 38-4 wire identification?? - Radioroslyn - 10-15-2017
Yup. It's so when you use the conecentric dial and spinning the dial to get to a desired station you don't hear all the others as you pass by them. It connects down to the volume control wipe (center connection) and is listed on the schematic as #43. Check the resistance to chassis ground to be sure that the switch isn't shorted, that maybe why it's disconnected.
RE: Philco 38-4 wire identification?? - CodyTerry - 10-16-2017
Thank you so very much brother! I'll update when I have a resolution.
RE: Philco 38-4 wire identification?? - Radioroslyn - 10-16-2017
OBTW Here's a little something to listen to whilst your working: https://archive.org/details/TalesOfTheTexasRangers
A little service tip, don't power it up with out the spkr plugged in. It will blow the pants off of #66 which in turn will takeout the 5Y4 and maybe if your unlucky #68 read $$$$. Without #65 (the field coil part of the spkr) in the circuit there is no load presented to #66 and it will keep charging up till it surpasses it's maximum voltage rating (450v when new) and then shorts. Only bad things happen after that.
RE: Philco 38-4 wire identification?? - CodyTerry - 10-16-2017
Well, I may have learned a very expensive lesson. Guess I will not know until I get a speaker for it. Need an H-29. Feeling kind of bummed about that. I just thought I'll throw a new power cord on it and power it up. Thought wow, the dial lamp sure is cool and all the while I had no clue ??
RE: Philco 38-4 wire identification?? - Radioroslyn - 10-16-2017
You can safely power it up if you remove the 5Y4 tube. This prevents any hv dc being applied throughout the set. At this point you can measure the hv ac at pin 3 to pin 5 of the 5Y4 without the tube plugged in. Should see about 600vac between these pins. Your set uses octal tubes (see socket in middle of pictorial). All of the pictured are bottom views (from the underside of the chassis) not the top.
Check ur PM box.
[Image: http://electriciantraining.tpub.com/14178/img/14178_24_2.jpg]
RE: Philco 38-4 wire identification?? - CodyTerry - 10-16-2017
Thank you Terry. I'll be looking tomorrow afternoon.
RE: Philco 38-4 wire identification?? - CodyTerry - 10-16-2017
I checked my PM. Awesome.
RE: Philco 38-4 wire identification?? - CodyTerry - 10-19-2017
Checked tonight per Fluke DVOM--600VAC present between pins 3&5. Seems all good.
RE: Philco 38-4 wire identification?? - Radioroslyn - 10-19-2017
Sehr gut!