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This probably is a simple question: however, I'm not sure how and what to connect to the antenna terminals.
I just finished restoring a Philco 38-7 chassis. There are 3 connections for the antenna - Red, Black and Ground.
Question #1 concerns the ground connection. Where do I connect this to get a ground. Can I connect this to the screw, that holds the cover to the power outlet? ( This should be a good ground connection. I also have PVC pipes, not copper.)
Question #2: What kind of antenna do I use - just a long wire, a dipole, or both and where do I connects it? To the Red, Black or both antenna connections?
Thanks
Posts: 26
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Just an additional note.
Not sure about how to connect the antenna and ground, I did a voltage check. I found that I have what I believe to be a ground loop. I measured about 46 VAC from any antenna connection (Red, Black and Ground) to the outlet cover screw. That I am sure isn't right. Where would this 46 VAC be coming from? The radio does work, on both BC and SW but I am not too happy measuring 46VAC from chassis and the antenna connections to ground.
Help!
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Suspect the 46VAC is normal, its low current, not a hard voltage. Bakelite cap no. 47 is across the power line tapped in the middle to the chassis, its acts as voltage divider of the mains voltage. Your meter only needs a small current to register a reading.
The red terminal is for a flying lead antenna. A 10 ft. 22 guage wire should do nicely. A Philco doublet antenna would connect across the red and blk terminals. Gnd terminal can be connected to outlet cover plate screw but will have some AC leakage current coming through the no. 47 cap. Prefer to leave it disconnected.
Should get excellent reception with just a flying lead antenna.
Richard
(This post was last modified: 03-06-2012, 05:28 PM by
rghines1.)
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(03-06-2012, 04:14 PM)Joejoe Wrote: Just an additional note.
Not sure about how to connect the antenna and ground, I did a voltage check. I found that I have what I believe to be a ground loop. I measured about 46 VAC from any antenna connection (Red, Black and Ground) to the outlet cover screw. That I am sure isn't right. Where would this 46 VAC be coming from? The radio does work, on both BC and SW but I am not too happy measuring 46VAC from chassis and the antenna connections to ground.
Help!
Schematic here.
http://www.nostalgiaair.org/PagesByModel...013256.pdf
Now then there may be a phantom voltages from a modern digital meter appearing because of the capacitors connected to the incoming power line (#47 on diagram.) It is not safe to operate this set until these components are replaced with safety compliant components.
You need to decide if you can replace ALL the electrolytics and paper capacitors, probably most if not all the small carbon resistors, and clean up the switches and connections. If you want to, you'll have a nice set in the end, and we will help you get there.
No meaningful fast track for this, IMHO.
Posts: 26
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Thanks for the input Richard. I was a little concerned when I measured the AC voltage. I did connect a quick antenna and picked up some SW stations. Plan to listen tonight, I am sure there will be more later on. Once again, thanks for your help.
Now that this one is done I am looking for another project. I will be picking up a Zenith this week-end, a 6 S 556, with 6 A 05 chassis. (That is what I was told anyway.)
This is sort of fun, both restoring and then listening to these old radios.
