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 Post subject: Magnavox Transformer (Output)
PostPosted: Mar Sat 21, 2015 9:24 pm 
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Joined: Nov Wed 19, 2014 11:19 pm
Posts: 12
Location: Silver Spring, MD
I'm looking for a replacement output transformer for my radio Mag: part # 330024G1, Thorndar'n #T22s74 or Merit # A-2905. Does anyone by chance know where I can get one of these for my restoration or by chance know a work around for the piece?

Thank You so much,
Jeff


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 Post subject: Re: Magnavox Transformer (Output)
PostPosted: Mar Sun 22, 2015 12:36 am 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 10966
Location: Mpls, Minnesota
This site shows a Merit A-2905 and a T-22S74
http://www.oldradioparts.com/2a23dfl.txt

Dave


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 Post subject: Re: Magnavox Transformer (Output)
PostPosted: Mar Sun 22, 2015 4:14 am 
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Joined: Mar Thu 24, 2011 6:23 am
Posts: 303
Location: New Jersey
As to a work-around (and there us almost always one!), what output tubes does it use, how many, what is the speaker impedance and can you post a schematic of the output section?


quote="squidbitz"]I'm looking for a replacement output transformer for my radio Mag: part # 330024G1, Thorndar'n #T22s74 or Merit # A-2905. Does anyone by chance know where I can get one of these for my restoration or by chance know a work around for the piece?

Thank You so much,
Jeff[/quote]


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 Post subject: Re: Magnavox Transformer (Output)
PostPosted: Mar Sun 22, 2015 1:48 pm 
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Joined: Nov Wed 19, 2014 11:19 pm
Posts: 12
Location: Silver Spring, MD
The transformer will go into the Magnavox 101A amp (SAMS S43-F12) if that helps with a work around suggestion.
Thanks for the great insight of where to look.


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 Post subject: Re: Magnavox Transformer (Output)
PostPosted: Mar Sun 22, 2015 1:51 pm 
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Joined: Nov Wed 19, 2014 11:19 pm
Posts: 12
Location: Silver Spring, MD
The amp uses 4 6V6GT tubes. the schematics are for the Maggi 101A Amp since I can't figure out how to upload the schematic I have where it is at all readable.
Thank you for your time

DrRick wrote:
As to a work-around (and there us almost always one!), what output tubes does it use, how many, what is the speaker impedance and can you post a schematic of the output section?


quote="squidbitz"]I'm looking for a replacement output transformer for my radio Mag: part # 330024G1, Thorndar'n #T22s74 or Merit # A-2905. Does anyone by chance know where I can get one of these for my restoration or by chance know a work around for the piece?

Thank You so much,
Jeff
[/quote]


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 Post subject: Re: Magnavox Transformer (Output)
PostPosted: Mar Sun 22, 2015 8:31 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 10966
Location: Mpls, Minnesota
This subject is now in three different threads, try to keep your subject confined to one thread.
viewtopic.php?f=19&t=273089
viewtopic.php?f=6&t=264009&p=2204937#p2204937
Dave


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 Post subject: Re: Magnavox Transformer (Output)
PostPosted: Mar Mon 23, 2015 9:30 pm 
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Joined: Nov Wed 05, 2008 3:36 am
Posts: 278
Location: Shinnston, West Virginia
Jeff

We may be able to use two single output transformers in a center tapped configuration
on the primary and secondary. I will check with Dick on Wednesday.

Oscar
nv3g


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 Post subject: Re: Magnavox Transformer (Output)
PostPosted: Mar Mon 30, 2015 11:52 pm 
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Joined: Nov Wed 19, 2014 11:19 pm
Posts: 12
Location: Silver Spring, MD
Does anyone have suggestions on the work around to replace a transformer pushing four 6v6gt tubes


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 Post subject: Re: Magnavox Transformer (Output)
PostPosted: Apr Wed 01, 2015 5:42 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 17961
Location: Warner Robins, GA
Based on the schematic I have you will need an output transformer with a 2.5 ohm secondary with a 1.7 ohm tap given both speaker voice coils are 5 ohms and are in parallel.

That said if you only use the internal speakers the 1.7 ohm tap is not necessary.

You will have to get Edcor to make one.

That will make the transformer initially expensive, but it will then be one that anyone else can order.

Not sure what the primary impedance should be, but for the operating point closest to the plate voltage it is 8K plate to plate impedance for two 6V6 tubes so taking a guess you would need a transformer with a 4K primary impedance.


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