[Jimradio]

Hi guy's, working on a "70" of which the RF-Coil primary is open, what should the reading be across the primary winding. I need to rewind it, have not done this before. I have the info from the Philco Bench on RF-Coils no info for the inductance.
Thanks

[morzh]

Jim

Unless there is data available, the best way is to unwind the coil counting the turns and then see what gauge it is (calipers will do) and wind it using the same or larger gauge (larger is fine as long as it fits in the bobbin).

The reading is not important; what important is the number of turns and, in case of tuned circuit, the length of the winding in total (affects inductance; this is why for this type of coils the gauge should be observed).
Ohms are not really a parameter with coils, it is a parasitic.

[Jim Koehler]

Hi Jim.....

I just finished rewinding 2 coils out of a Model 84.....the Ant. and Osc. coils. Both the primaries had the "Green Gunge". This is a chemical reaction between the silk covered #36 primary coil and the celluloid underlay. Moisture, I'd assume, would be a factor in this. 

Use #36 enamel wire as a replacement. Don't worry about the turns needed.....measure the width of the old coil with a micrometer, remove the old wire, lay in the new to the same width dimension. Remember, the new wire has to be laid in the same direction as the old! And, be careful around the celluloid....it pretty fragile if you want to keep it. Doing the whole job under an illuminated magnifying lamp would make the going a lot easier. (wish I had one!)

Good luck with the project and all of us here are expecting a full report when you're finished.

A Merry Christmas and a Happy Near Year!

...Jim

[morzh]

For 1st and 2nd RF yes, the primary number of turns is not that important (though I would try to stick reasonably close to original).
For the IF coil (#19) both windings have to be as close as possible to the original as they are part of tuned circuit.

[Jimradio]

Thank you for your posts.........................

[TV MAN]

Jim, here is my thread on restoring one of these. Mike (Morzh) has at least one thread on his also. http://philcoradio.com/phorum/showthread.php?tid=8626  Here you can see what I ran into, how I fixed, and some of my mistakes. I too had to redo the RF coil. Some of the links may not work since some things have been moved within the website. Have fun

Tech section and notebook has some info on this radio too.

[Jimradio]

                   
Hi guy's and Merry Christmas......had a good Christmas, got the Philco 70 up and running after a recap and  rewound the RF Coil did some cleaning and painting on the chassis.
 The alignment schematic shows three adjustments on the back of chassis but this one has only two. According to the tube configuration this is the early model below B22,000? I can find only one alignment procedure, is there another one. I do have document's from the Chuck at the Philco Repair Bench.
Also the volume seems a little down on distance station's the strong local stations are fine.
 I want to thank all you guy's on this forum and the one's that responded to my post's
Here are some pic's. Do have some work on the cabinet, but I'm over the hump as they say.

[Steve Davis]

Could it be that you missed the one that has a metal cover over it? It is all the way to the left side of the chassis. This one is covered because, the trimmer has B+ voltage on it.

Steve

[Jimradio]

Could it be that you missed the one that has a metal cover over it? It is all the way to the left side of the chassis. This one is covered because, the trimmer has B+ voltage on it.

Steve

Wow am I losing it thank you so much...........