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  #1  
Old 03-01-2019, 03:56 PM
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DavGoodlin DavGoodlin is offline
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Crosley 517A - "fiver'

Hi fellow tube polishers, I got a model here that was 100 percent original except for one tube, the 6U7 which was a Sylvania with the green leaf logo. I'm fixing this for a friend who got it 10 years ago and set it out on display, never plugging it in. Its easier to link than post a pic but Ill do both.
https://radioatticarchives.com/radio.htm?radio=393
Crosley_517A_Haworth.jpg
Its not hard to see why Crosley made a very collectible radio, a 1937 BC/SW2 set with 6A8-6U7-6Q7-6K6-5Y3, same as a GE and a Zenith I have of the same year. This set is compact with a 4" field coil speaker and 4-wire speaker plug. The only tube failing a test was the 6Q7, an original Ken-Rad/Crosley-branded ST tube I only have a metal tube replacement for.

The wax caps all seem to be rated .02 except for two .01 and just two electrolytics. I already changed the cord, added a fuse and two Y2 caps from either side of AC to chassis ground.

It would be interesting to hear of anyone's experience as I give this a power up and try to align it. The instructions in Riders are quite interesting to align SW especially since there is a image frequency at 910 Kc from fundamental.
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Old 03-01-2019, 08:02 PM
dieseljeep dieseljeep is offline
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Quote:
Originally Posted by DavGoodlin View Post
Hi fellow tube polishers, I got a model here that was 100 percent original except for one tube, the 6U7 which was a Sylvania with the green leaf logo. I'm fixing this for a friend who got it 10 years ago and set it out on display, never plugging it in. Its easier to link than post a pic but Ill do both.
https://radioatticarchives.com/radio.htm?radio=393
Attachment 198333
Its not hard to see why Crosley made a very collectible radio, a 1937 BC/SW2 set with 6A8-6U7-6Q7-6K6-5Y3, same as a GE and a Zenith I have of the same year. This set is compact with a 4" field coil speaker and 4-wire speaker plug. The only tube failing a test was the 6Q7, an original Ken-Rad/Crosley-branded ST tube I only have a metal tube replacement for.

The wax caps all seem to be rated .02 except for two .01 and just two electrolytics. I already changed the cord, added a fuse and two Y2 caps from either side of AC to chassis ground.

It would be interesting to hear of anyone's experience as I give this a power up and try to align it. The instructions in Riders are quite interesting to align SW especially since there is a image frequency at 910 Kc from fundamental.
I have one from a fellow old radio collector. It's in nice condition, but the previous owner drilled a hole in the front panel to right of the dial.
I just looked up the schematic and I remembered that the 5Y3 was used as a half-wave rectifier.
I haven't turned it on in at least 25 years.

Last edited by dieseljeep; 03-01-2019 at 08:06 PM. Reason: I meant to say the hole is for a 1/4 headphone jack. I left it that way.
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Old 03-04-2019, 11:20 AM
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DavGoodlin DavGoodlin is offline
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I have it recapped now and used 22mf@450V in place of the 16mf originals. The wax caps were all original as were the two PS caps.

The higher value resistors were almost all the colored dog-bone style and all checked within 10-20%, so I left them in place. 350/60/40 ohm resistors in the bias supply, are close too but look like fusible types and look like insulated braid over a wire-wound.


Dave - I noticed too that the 5Y3 is connected with diode halves in parallel. The B= is supposed to be 225 and and 160 v on plate of the 6K6. Looks like the field coil drops over 60 volts. Not as high a voltage set as an RCA or Philco. I used 450v caps anyway.
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Old 03-04-2019, 12:29 PM
dieseljeep dieseljeep is offline
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Originally Posted by DavGoodlin View Post
I have it recapped now and used 22mf@450V in place of the 16mf originals. The wax caps were all original as were the two PS caps.

The higher value resistors were almost all the colored dog-bone style and all checked within 10-20%, so I left them in place. 350/60/40 ohm resistors in the bias supply, are close too but look like fusible types and look like insulated braid over a wire-wound.


Dave - I noticed too that the 5Y3 is connected with diode halves in parallel. The B= is supposed to be 225 and and 160 v on plate of the 6K6. Looks like the field coil drops over 60 volts. Not as high a voltage set as an RCA or Philco. I used 450v caps anyway.
Those bias resistors are those strange flexible WW types.
Regarding the E-caps, there isn't much around that are rated at between 160 and 450 volts.
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Old 03-06-2019, 01:28 PM
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DavGoodlin DavGoodlin is offline
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The damaged WW resistor I replaced with a 1-watt 390 ohm and the voltage on the 6Q7cathode is exactly right at 2.5. Other voltages agree with Riders, so we're done with resistors.

This is a little guy not a big-sound console, so I tried swapping 6K7 for 6U7 and a metal 6Q7, (original ST tubes had tested borderline) without much improvement. Broadcast reception fair, even with a 10' lamp cord antenna. The SW band even pulls in something with no antenna attached, odd. It needs an alignment just to make it incrementally better if nothing else. Next step is alignment using a Hickok 277x.

The Riders IF alignment procedure from Crosley, no doubt is a bit different than what I'm used to. You connect the generator at 455 kHz to the 6A8 grid via .02 uf cap, but the meter goes across the OPT primary "with a .1 mf cap in series to prevent meter damage from DC" Also odd, not a ac vtvm across the voice coil??
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Old 03-07-2019, 10:52 AM
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DavGoodlin DavGoodlin is offline
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The alignment went as expected. IF cans were way off, like 445 kHz. After peaking them, fidelity on AM was better but not much louder.

The dummy antenna recommended for AM alignment was a .02 cap across terminals with generator connected to A and G as well.
I could pull in one of the few music stations; 740 AM from Toronto, which is AWOL some evenings. Volume is "polite" even at max and the tubes seem to run cool.

Dummy for SW band needed to be a 400 ohm resistor but I only had a 180, which did not seem to matter. The osc/ant adjustments made for better selectivity. The 25 meter and 49 meter bands seemed to open up as it got dark at 7.

This set is about as small as late-30s AC-sets come but it was easy and would be perfect at a desk or anywhere else you are no further than 5 feet away.

I have a '37 Zenith 5R125 tombstone like this and the wire antenna works best on the floor, putting it further from interference sources like the PC and other switch-mode hash sources.
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Last edited by DavGoodlin; 03-07-2019 at 10:56 AM.
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