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 Post subject: Need help identifing transformers
PostPosted: May Mon 06, 2019 4:32 pm 
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Location: Marquette MI
Hi Guys

I picked up a couple of Thordarson Transformers at a recent swap and am trying to figure out just what they are. I am used to what I call the "normal" numbering system for Thordarson, i.e. two numbers, followed by a letter, followed by two numbers. These transformers have four numbers stamped in the "type" position on the data plate. I have attached a photo of the top and of the bottom of the transformers.

The type numbers are too small (and a little corroded) to read in the photo but the larger transformer is stamped "Type 5100" and the smaller transformer is stamped "Type 5739".

Anyone familiar with this ID system and can help me ID these transformers?

Thanks for reading and have a great day.

Dave


Attachments:
Trans Side.JPG
Trans Side.JPG [ 72.14 KiB | Viewed 390 times ]
Trans Top.JPG
Trans Top.JPG [ 82.77 KiB | Viewed 390 times ]

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 Post subject: Re: Need help identifing transformers
PostPosted: May Mon 06, 2019 4:39 pm 
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Joined: May Tue 30, 2006 4:46 pm
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Location: Santa Rosa, CA
The larger one is probably a push-pull audio output transformer.

P (plate) B (B+) P (plate).

How many wires on the smaller one?

Rich


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 Post subject: Re: Need help identifing transformers
PostPosted: May Mon 06, 2019 10:48 pm 
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Location: Marquette MI
Hi Rich

Thanks for the reply.

The larger transformer is an odd duck. I should have posted a photo of the other side as well. It has four terminals. Two are marked "F" and two are marked "G". There appears to be two separate windings with an "F" and a "G" on each end of each winding (continuity between one "F" and one "G" and continuity between the other "F" and "G" terminal). The two windings are not connected to each other. Do not think I have ever seen anything like it before.

The smaller transformer is more conventional with one winding marked "B" and "P" (B+ and Plate?) and the other is a center taped winding marked with a "G" on each end and the center tap marked "F". I think this one is a single end to push pull inter-stage (audio) transformer, but would like to find some data on it. I can measure the impedance ratios, etc.

Guess I will just have to "cut and try" to see what they do.

Thanks again for the input.

73, Dave

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 Post subject: Re: Need help identifing transformers
PostPosted: May Mon 06, 2019 11:17 pm 
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Location: near ST Louis Mo 62002
wa8dof wrote:
Hi Rich

Thanks for the reply.

The larger transformer is an odd duck. I should have posted a photo of the other side as well. It has four terminals. Two are marked "F" and two are marked "G". There appears to be two separate windings with an "F" and a "G" on each end of each winding (continuity between one "F" and one "G" and continuity between the other "F" and "G" terminal). The two windings are not connected to each other. Do not think I have ever seen anything like it before.

The smaller transformer is more conventional with one winding marked "B" and "P" (B+ and Plate?) and the other is a center taped winding marked with a "G" on each end and the center tap marked "F". I think this one is a single end to push pull inter-stage (audio) transformer, but would like to find some data on it. I can measure the impedance ratios, etc.

Guess I will just have to "cut and try" to see what they do.

Thanks again for the input.



73, Dave


That would make it a PP interstage transfomer .

http://www.bunkerofdoom.com/xfm/THORDAR ... 400_05.jpg 5739 is on this page

http://www.bunkerofdoom.com/xfm/THORDAR ... 400_07.jpg 5100 on this page

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 Post subject: Re: Need help identifing transformers
PostPosted: May Tue 07, 2019 12:15 am 
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Location: Dayton Ohio
push-pull plate to SE grid seems a bit odd to me.

-Steve

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 Post subject: Re: Need help identifing transformers
PostPosted: May Tue 07, 2019 12:37 am 
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Thanks for the reply's guys.

Mark, that is the exact info I was looking for. Don't know why I could not find it. As they say, "a mind is a terrible thing to waste".

You are my hero.

73, Dave

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 Post subject: Re: Need help identifing transformers
PostPosted: May Wed 08, 2019 1:01 am 
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azenithnut wrote:
push-pull plate to SE grid seems a bit odd to me.

-Steve


It is PP to two grids (PP)

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 Post subject: Re: Need help identifing transformers
PostPosted: May Sun 12, 2019 2:49 pm 
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That makes much more sense. Thanks!

-Steve

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