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The following requirements must be followed when advertising personal antique radio / TV / audio / phono items (such as discussed in the forums here) for sale in the classifieds forum:

  • TITLE--Titles must START with: FS (when selling) or WTB (when wanting to buy) or Trade or Free at the beginning of the title.
  • PRICE--FS posts must have an "asking" price and offers may be sent by PM. Are you parting something out? ... price each major part (not things like screws and nuts)
  • LOCATION--There must be a location somewhere in the ad or the members profile (City & State or Zip Code are the minimum requirement). This includes WTB ads.
  • Discussion -- This is NOT a discussion forum. If you're not buying or supplying or suggesting a relevant solution, don't post - send a Private Message. Comments on pricing will be deleted.
  • Ads are limited to two per day, and may not be bumped sooner than 7 days after the last post to the thread.
  • No outside sales links are allowed other than to pictures of actual items being sold. No links allowed to eBay, Craigslist etc.
  • First to post to an item for sale stating "I WILL TAKE IT" it is first in line. Subsequent claims will be followed in the order they are posted. Claims to "Take it" can be conditional on unknowns such as shipping costs.
  • Any "PM sent" posts without posting a reason for the PM will be deleted as they are meaningless to anyone else reading the thread.
  • Once a deal is made, edit the title to say so.
  • Topics will be locked when deals are made.




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 Post subject: WTB chokes!
PostPosted: Dec Mon 24, 2012 5:29 pm 
Member

Joined: Feb Mon 28, 2011 11:14 pm
Posts: 270
Location: Detroit, Michigan
Does anyone have any old choke laying around? I need one 30 henry choke, one 1000 henry choke, one 2000 henry choke, one 100 henry choke, and one 25 henry choke. thanks,
john


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 Post subject: Re: WTB chokes!
PostPosted: Dec Mon 24, 2012 10:17 pm 
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Joined: May Tue 30, 2006 4:46 pm
Posts: 6070
Location: Santa Rosa, CA
Are you sure you need 1000 Hy and 2000Hy?

Mighty rare chokes, I'd say.

Rich


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 Post subject: Re: WTB chokes!
PostPosted: Dec Mon 24, 2012 10:27 pm 
Member

Joined: Feb Mon 28, 2011 11:14 pm
Posts: 270
Location: Detroit, Michigan
Rich, W3HWJ wrote:
Are you sure you need 1000 Hy and 2000Hy?

Mighty rare chokes, I'd say.

Rich

do you think i would be able to locate these?


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 Post subject: Re: WTB chokes!
PostPosted: Dec Mon 24, 2012 10:56 pm 
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User avatar

Joined: Sep Thu 14, 2006 3:27 pm
Posts: 5614
Location: Carmel, Indiana
Radiosmarts1234 wrote:
Rich, W3HWJ wrote:
Are you sure you need 1000 Hy and 2000Hy?

Mighty rare chokes, I'd say.

Rich

do you think i would be able to locate these?


Even if you did find one, I'm not so sure you'd even be able to lift it.

_________________
Michael Feldt
www.indianaradios.com


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 Post subject: Re: WTB chokes!
PostPosted: Dec Mon 24, 2012 10:58 pm 
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Joined: Mar Fri 14, 2008 1:40 pm
Posts: 8797
Location: SE USA
They are out there but only in very low current ratings , ie less than 10ma. Is this for a choke-coupled audio stage?

_________________
The beatings will continue until the morale improves


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 Post subject: Re: WTB chokes!
PostPosted: Dec Mon 24, 2012 11:39 pm 
Member

Joined: Feb Mon 28, 2011 11:14 pm
Posts: 270
Location: Detroit, Michigan
heres where im getting this info from. It says henrys but im starting to thing it could be micro henries http://www.earlytelevision.org/pdf/qst_4-38.pdf


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 Post subject: Re: WTB chokes!
PostPosted: Dec Mon 24, 2012 11:56 pm 
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Joined: Mar Fri 14, 2008 1:40 pm
Posts: 8797
Location: SE USA
I'm way out of my league on something like that. What I was aiming at earlier is that often the secondary of an old 1:3 interstage audio transformer will have enough inductance to get by in choke coupling applications.

FWIW - AES has a Hammond P-T156C. 150Hy@8ma.

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The beatings will continue until the morale improves


Last edited by Jack Shirley on Dec Tue 25, 2012 12:00 am, edited 1 time in total.

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 Post subject: Re: WTB chokes!
PostPosted: Dec Mon 24, 2012 11:56 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 6595
Location: Minneapolis, MN USA
Here is partial product info page for the specified Thordarson transformer.
Jack is correct, it is Henries.

http://antiqueradios.com/gallery/d/1539 ... darson.png


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 Post subject: Re: WTB chokes!
PostPosted: Dec Tue 25, 2012 12:37 am 
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Joined: Mar Wed 28, 2012 11:01 pm
Posts: 117
Location: Toronto, Ontario
Not sure if this is much help...

I found this catalogue: http://www.vintageradio.com/history/Thordarson1947.pdf

Which states that the Thordarson 'T-29C27' is now (as of 1947) named 'T-20C50,' and the catalogue states that the T-20C50 part is a 350H @5mA part, while that PDF you linked states that the T-29C27 is a 1000H part.


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 Post subject: Re: WTB chokes!
PostPosted: Dec Tue 25, 2012 1:47 am 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 27084
Location: Pocasset, Cape Cod, MA
Choke inductance ratings before about 1950 were "stretching the truth" as they were measured with no DC flowing. I suppose since everyone did it, nobody wanted to fess up and be at a competitive disadvantage. I have identical UTC chokes with different ratings on the boxes.


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 Post subject: Re: WTB chokes!
PostPosted: Dec Tue 25, 2012 7:45 am 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 2370
Location: Seattle WA US
FWIW, the 1945 catalog shows T29C27 as 500 Henrys, at 0.5ma DC current. DC resistance 6150 ohms.
That was a lot of fine wire, and the whole thing only weighted one pound !!

--Chuck


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