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1936 Model 600 Oscillaltor coil - Printable Version

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1936 Model 600 Oscillaltor coil - Radioroslyn - 01-05-2010

I started working on it only to find that osc coil is open. Got to thinking how hard would it be to make a replacement? I've got a bunch of national XR-50 form (1/2" slug tuned) and wire from 30G down to 50G. Tuning cap is about 365mmfd + 20mmfd for the trimmer. Osc needs to tune 1010kc to 2260kc. The original uses the grid /plate for feedback. Wouldn't be apposed to changing it to a grid cathode circuit like most AA5's. Any ideas on how many turns for the windings? I don't mind experimenting and have jig I can wind the coil in with a turns counter.
Looking forward to hearing any comments.
Terry

Re: 1936 Model 600 Oscillaltor coil - Radioroslyn - 01-09-2010

The 600 is on the road to recovery. After determining both the primary and secondaries of the osc coil were open I carefully took it apart and rewound it. Primary was bad in two places secondary only one but would have had to rewind both because of where they where broken. Haven't yet finish it but did wind the primary (the larger winding)tonight. I found my General Radio cement had dried up so have to get some mek to get it back in usable shape. Love the smell of that stuff reminds me of fixin' radios Then I can wind up the secondary. If anyone needs the data it's primary is 125T of #36G & Secondary is 25T of #36G. Hope to have it working tomorrow!
Terry

Re: 1936 Model 600 Oscillaltor coil - Joe Rossi - 01-09-2010

Terry, Looks like your getting it done. Keep plugging away friend, we're waiting for the next installment! Icon_smile

Re: 1936 Model 600 Oscillaltor coil - Radioroslyn - 01-10-2010

Tnx for the encouragement! Here's a pic of the primary. Dang wire is like hair! Maybe smaller.
Terry

Re: 1936 Model 600 Oscillaltor coil - Ron Ramirez - 01-10-2010

Sorry I couldn't help you with this one, Terry, Glad to see you figured it out, and many thanks for sharing the specs (number of turns and wire gauge sizes) with us. I've owned two 602 sets but no 600. The first 602 was an easy recap and then played well, coils were OK. The second one, I have yet to restore.

Re: 1936 Model 600 Oscillaltor coil - Radioroslyn - 01-10-2010

Note from site admin: Sorry, but the photo which was attached to this post is no longer available.

Re: 1936 Model 600 Oscillaltor coil - Radioroslyn - 01-10-2010

Secondary is on.






Note from site admin: Sorry, but the photo which was attached to this post is no longer available.

Re: 1936 Model 600 Oscillaltor coil - Radioroslyn - 01-10-2010

Ready to be installed! Hope I'm not boring with this blow by blow repair.
Terry

Re: 1936 Model 600 Oscillaltor coil - Radioroslyn - 01-10-2010

The old '600 is up and running, in a fashion. Will tune the first 100kc or so at the bottom of the band then the osc quits. So still have a few bugs to workout but am hopeful I'll be able to get her in shape.
Terry

Re: 1936 Model 600 Oscillaltor coil - Radioroslyn - 01-11-2010

After reversing the secondary winding (feedback) on the oscillator coil the set is working fine. The IF/detector was acting up as it would go in and out of oscillation at will. Replacing the 77 tube seems to have corrected this problem. Thank goodness as I didn't want to rewind the IF transformer! Going to make some BED resistors to replace the modern ones I put in. Set is working fine!!
Terry

Re: 1936 Model 600 Oscillaltor coil - Radioroslyn - 01-27-2010

Dang I spoke too soon! It first I thought it was the #77 tube. Replace it and it seemed to work ok for a while. And it was back to it's old tricks of very noisy reception and the detector would quite oscillating. One by one replacing the resistors and mica cap in the detector it seemed like it was working better but still would get noisy and go out of oscillation. So have come to the conclusion it the IF can is bad. I've seen this same some of problem with other sets that don't use a regenerative detector. Am looking forward to taking the IF can apart and looking for some green or if I'm lucky a bad joint. Anyway I'll see what tricks I can pull out of my bag to fix this one. I posted in the ad section for a IF can or chaiss .
Terry

Re: 1936 Model 600 Oscillaltor coil - Radioroslyn - 01-10-2011

Well it's been almost a year since I've played with this guy. I was getting a bit frustrated with an intermittent problem. I replaced just about every cap and resistor, the IF transformer, the mixer and IF amp tubes, and it was still giving me a run for my money. Would still lose gain and the detector would go out of oscillation. When it was working, about 80 percent of the time it played very well then the volume would drop to about half and the signal would get much noisier. I did find a minor problem the detector plate voltage was down a bit. Was 36v should be 47v so changed the value of the voltage dropping resistor and now I've got about 55v. It's been on the bench for a hour or so playing just dandy. I've got my fingers crossed.
Terry
Here's a pic from the gallery http://www.philcoradio.com/gallery/1936b.htm#5
Mine must be an earlier version as it only two sets of louvers in the top

The saga continues.... - Radioroslyn - 01-14-2011

Well it's been playing great since the last time I had it one the bench(1 10 11). For 3 or 4 hours a day for 4 days till this morning it been wonedrful. I found myself awake and not able to get back a sleep at 4:30 this morning. So I went out to the living room and snapped on the little 600. It played fine for awhile but started back to it's old tricks. This time it just got very noisy. The detector stage held firm and stayed on the verge of oscillation as it should and there was a slight increase in the level of hum. Back to the bench it went and I took a look. As before everything looks and check out good I did run a couple of extra ground wires to the 77 socket and the wiper of the volume control also cleaned with a bit of Deoxit it was just a bit noisy. Getting to put it back in it's cabinet see if this time I can get more than 4 days out of her.
Terry
ps I don't think this radio like me!

Re: 1936 Model 600 Oscillaltor coil - Ron Ramirez - 01-14-2011

Terry, have you tried reflowing the solder on the grid caps of the 6A7 and 77 tubes?

Re: 1936 Model 600 Oscillaltor coil - Radioroslyn - 01-14-2011

No I haven't but have tried a few different 6A7's and 77 toobs. It's back in the living room work fine right now. Hope it lasts!
Tnx for your input
Terry