DeForest-Crosley Power Transformer

[Ralph Spracklin]

I am restoring a DeForest Crosley ‘Meteor’ 6D531. This radio was manufactured by Rogers Majestic of Toronto. Most of the work is completed, but the Power Transformer is kaput. It would run too hot to the touch after about five minutes, and pitch/tar was oozing from the bottom end. As a relative newbie to this hobby I don’t have a lot of experience with Power Transformers. I have rigged up a winding apparatus that works very slick, and am going to attempt at rewinding the damaged tranny. As magnetic winding wire is not cheap to purchase I want to be certain I get it right first time around. My question is regarding the 6.3 Volt winding. See schematic and help me figure out if this is a twelve volt winding tapped at 6.3 Volts. Or is it a less than 12 Volt winding tapped at 6,3 Volts with the other side of this same winding being uses to power the Dial lights. To add to this confusion, I do not know the voltage of the dial lamps and the schematic does not give me that information. My thought is to run two dial lights in parallel with the 6,3 tube filaments and use two # 47 dial lamps, making it a single winding of 6.3 without any Tap being used. Also I do have an old Westinghouse transformer (no centre Tap on the 6,3 volt winding) that should run the thing, but it is a bit on the large side and there is not enough space on the chassis to mount it. So my plan is to wire this transformer via an power umbilical cord to test this set out before I pump any more dollars into it .In other words, get the set working first.
http://www.nostalgiaair.org/PagesByModel/352/M0029352.pdf

Thanks in advance for any suggestions.

[Ralph Spracklin]

I am posting this again to try to make it clearer as to the information I am seeking regarding this DeForest Crosley Meteor 6D531, for which I intend to rewind its Power Transformer. The 6.3 Volt filament winding is the stickler, and which I must get it correct the first time. Look at the schematic above in my first post and try to answer for me the problem that I am running into. Is this a 6.3 Volt winding across the full winding which also has a centre-tap, or is it a higher voltage winding, of maybe 12 Volts, or whatever, which is tapped at 6.3 Volts. The second part of my question is, whether I could just make the new winding a 6,3 Volt winding, which could carry all the filaments and the two dial lamps.(possibly two #47s). Why would they design it the way they have?? Am I missing something?? What is the need for the centre-tap on this particular winding of this radio anyway??

Regards
Ralph

[Jean Marcotte]

This is a 6.3V winding. Dial lamps and heaters are all in parrallel together. The center tap to the chassis is there to balance the filaments to lessen hum. Many radios just don’t have that center tap.

[Ralph Spracklin]

Much thanks Jean. It was only last evening I stumbled uon the same answer from another source. Do you or anyone else know how this Tap achieves this result. I can only suppose that this 6.3 Volt winding setup will still work without it being centre tapped??

Ralph

• This reply was modified 3 years, 1 month ago by Ralph Spracklin.
• This reply was modified 3 years, 1 month ago by Ralph Spracklin. Reason: Much thanks Jean. It was only last evening I stumbled uon the same answer from another source. Do you or anyone else know how this Tap achieves this result. I can only suppose that this 6.3 Volt winding setup will still work without it being centre tapped?? Ralph

[Gordon Dann]

is your transformer hot with all the tubes pulled? if yes then most probably a bad winding, but what one ? most likely the primary winding witch is the inside winding . best to buy a new one . Take a look at mouser Canada for a Hammond classic 200 series . it will most likly not be worth rewinding as it is not a simple job . if your transformer runs cool with all the tubes pulled then look for a short . hope this helps. Gordon

[Ralph Spracklin]

Hello Gordon

Thanks for your interest. Never tried tubes out approach. The transformer was so hot after only 5 minutes operarting, and so much tar oozing out of its base, I knew it was shot. So I pulled it and opened it up, only to discover that all the insulation on the windings was blackened and it stunk something terrible. While I think there was indeed a short involved, I was unsure where it was located. While unwinding the thing, I discovered it was most likely in the primary, which indeed proved to be correct.

As to the rewinding process, I have everything I need to work with on this rewinding project and one day soon I will go ahead with it, and complete the job, for good or for evil.

Regards

Ralph

• This reply was modified 3 years, 1 month ago by Ralph Spracklin.
• This reply was modified 3 years, 1 month ago by Ralph Spracklin.

[Ralph Spracklin]

Hello Dan

I never did receive a message from you with your email address. Anyway, the link below will give you a very good idea of how your DeForest Crosley 6D531 should look when finished. And maybe you have already seen these pics. This is not pics of my set. As I mentioned on my Private Message to you, re my camera which contains all my radio pics. I still do not have access to my camera due to my Christmas Dinner has been cancelled due to Covid. And I still do not know when I will gain access to those pics. In the meantime, I hope this link will give you some idea of how it should look. I will still send my pics of this radio as soon as I get them.

https://www.radiomuseum.org/r/deforest_meteor_6r5316_r_53.html

In regards to this radio, would it be too much trouble for you to send me the Power Transformer Voltages with the tubes pulled from your set. I am trying to determine the exact voltages in order to have the exact number of turns for secondary winding, as I am ready to rewind it.

Thanking you in advance.

Regards

Ralph

• This reply was modified 3 years ago by Ralph Spracklin.

[Dan Walker]

Ralph; [6D531] radio
I have the voltages from the transformer with the tubes removed.
The heater pins are 7 volts AC.
The secondary winding going to the plates of the 80 tube are 780 volts AC.
the AC volts going to the center tap are as follows 383 and 388.
The volts going to the heater of the 80 is 5,89 volts AC.
I hope this gives you the information you need.

My radio is a table top, not a console
Here is what it look like now , and a photo of what I hope it will look like after I am done.
I have a lot of work ahead of me, but the cabinet won’t get done until spring.
Dan in Calgary

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[Ralph Spracklin]

Hello Again Dan
I think that somehow we have some of our wires crossed. My Radio is a DeForest Crosley 6D531. It is a five tube set with the following tube line-up Numbers: 80; 6A7; 6K7; 75; 6F6.
The pictures you posted here of your set, says it is an 7 tuber Model 8D723. It shows that the tube line up for your model uses a tube line-up as follows: 2X3; 2X3; 6J8; 8K7. 75; 41 6X6. So that is two times 2X3, 1/2 wave rectifiers, rather than a single # 80
You mentoned on the voltages you gave me, that those voltages on your set was going to the # 80 tube??? But apparently your set should not have a #80 tube. It should have two 2X3 tubes. I am wondering if Rogers somehow used the 6D531 chassis in your model, because apparently it was not uncommon for Rogers to make some mid-production changes when building some of their radios. But any way, if your set is a seven tuber, that would mean that the B+ voltages supplid to the rectifier would possibly higher than what my set calls for, and wouldnot apply to my set.

Man that is quite a rebuilding chore you have undrrtaken on your Table-top model. Actually my set is a Tombstone Model

Thanks for your efforts on this one. Maybe we will still get to the bottom of this hic-up.

Regards

Ralph

• This reply was modified 3 years ago by Ralph Spracklin.

[Dan Walker]

You are right Ralph….
The photos I posted are the wrong radio Please disregard them My mistake.
BUT the voltages I gave you are from my 6D531 radio
I am sorry about that
Dan in Calgary

[Ralph Spracklin]

Thanks Dan. That clears it all up very quickly. Now, when I rewind the tranny, I will reduce the number of secondary turns to reflect voltages that are most closer to original spec. I think 375-0-375 or 750 Volts is closer to what I am looking for. Your 6.3 and 5.0 windings are also higher than they should be. this of course caused by applying higher Primary voltages of 120 Plus used in our present day hydro systems, which will in turn increase all secondary voltages on most vintage radio transformers. Reducing number of secondary turns, also saves some valuable winding space in the allotted window in the core of the tranny. Of course there other ways to reduce secondary voltages.

I think. all systems are go, and I am now ready to attempt the re-winding process. Much thanks for your parience and help.

Ralph

• This reply was modified 3 years ago by Ralph Spracklin.
• This reply was modified 3 years ago by Ralph Spracklin.

[Ralph Spracklin]

Hello Dan and All
Here are some pics of my Deforest Crosley 6D531. I used another camera to speed things up. I slid the chassis into its cabinet, even though it is not completed, But it shows what it will look like when finished. The three knobs below the tuning dial are not original. I crafted them from autobody filler and painted them.. I think they give me a reasnoable facsimile Those black and white wires which are taped together is my power umbical cord from which steal my power, from another radio, until my transformer re-wind is completed.

Enjoy and I hope you all had a great Covid Christmas.

Ralph ( Something went wrong, it will only allow me to send one pic at a time. Maybe I am doing something wrong. I will try again to send a couple of others.)

• This reply was modified 3 years ago by Ralph Spracklin.
• This reply was modified 3 years ago by Ralph Spracklin.
• This reply was modified 3 years ago by Ralph Spracklin.

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[Ralph Spracklin]

Here goes again.

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[Ralph Spracklin]

And Again

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[Dan Walker]

Ralph. I finally got a day that was a little warmer, so I took these to show you the cabinet for my 6D531.
I won’t get to it until the spring.
Dan in Calgary

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