Forum rules
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::
- Titles must START with : FS (for sale) or WTB (want to buy) or Trade or Free at the beginning of the title..
- 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)
- There must be a location somewhere in the ad or the members profile (City & State or Zip Code are the minimum requirement).
- 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.
- 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.
- 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 and the thread will be locked
If your thread or post disappears - read the rules again - no warnings or explanations will be given when threads or posts are deleted.
 
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stancherry
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Post subject: WTB Philco 48-482 Output transformerEDIT: Found one  Posted: May Thu 03, 2012 8:24 pm |
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Joined: Jun Fri 03, 2011 9:53 pm
Posts: 7
Location: South Carolina
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EDIT: Found one
Last edited by stancherry on May Sat 05, 2012 9:40 pm, edited 2 times in total.
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Tom Bavis
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Post subject: Re: WTB Philco 48-482 Output transformer Posted: May Fri 04, 2012 1:22 am |
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 3851
Location: Rochester NY USA
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6V6 output transformer will be about 5K to 6K primary, 3-4 Ohms secondary. What's the mounting hole spacing?
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stancherry
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Post subject: Re: WTB Philco 48-482 Output transformer Posted: May Fri 04, 2012 3:15 pm |
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Joined: Jun Fri 03, 2011 9:53 pm
Posts: 7
Location: South Carolina
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Tom,
Thanks for the reply. I'm a newbie at this and have been working on this ( off and on) for quite awhile. After replacing the e-caps it still wouldn't play. My tube tester didn't have the settings for the tubes so I bought a full set (from a seller recommended by badrestorer). I heard music from it for maybe the 1st time in what, 60 years? WHAT A COOL HOBBY!! Alas, after about 10 minutes it quit. Test determined that output tran read infinity ohms.
Now, to answer you question, the mount measures 2.5 inches center-center. By the way, it has a lead from the secondary going to the volume control, is that critical??
Before I end this let me just say THANK YOU to all of the posters who take the time to help us newbies, I have learned so much from this forum.
Regards to all!
Stan
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Dave Doughty
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Post subject: Re: WTB Philco 48-482 Output transformer Posted: May Fri 04, 2012 4:55 pm |
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 13632
Location: Utica, NY 13502 (USA)
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This radio will need all of it's paper caps replaced, too. Leaky caps in the audio section probably took out the original transformer. Yes, the lead from the secondary needs to be there as it is part of the negative feedback and bass control circuit. Also critical is how the leads from the transformer are hooked up. If wired wrong, positive feedback will result but that's easily solved by reversing the leads of either the primary or the secondary.
I'll look for a replacement transformer for you.
Dave
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stancherry
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Post subject: Re: WTB Philco 48-482 Output transformer Posted: May Fri 04, 2012 6:06 pm |
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Joined: Jun Fri 03, 2011 9:53 pm
Posts: 7
Location: South Carolina
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Dave, Tks for the reply. No doubt, you are correct that I foolishly took out the transformer myself. If I understand what you said about the secondary lead (neg. feedback), I guess that rules out a universal transformer (such as the AES P-T291)?? At anyrate your help in finding a replacement is very much appreciated. Meanwhile, doesn't seem to be a shortage of paper caps to keep me busy.  Thanks again, Stan
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Tom Bavis
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Post subject: Re: WTB Philco 48-482 Output transformer Posted: May Sat 05, 2012 3:27 am |
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 3851
Location: Rochester NY USA
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That AES transformer should work fine. As mentioned, it might be necessary to swap the primary or secondary leads. If Dave doesn't turn something up, I probably can. In case you don't have it, the 20-page Philco service bulletin ins on my web page: http://www.audiophool.cjb.net/Misc/philco_48-482.djvu (You'll need the DjVu plug-in or similar to view or print it).
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Dave Doughty
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Post subject: Re: WTB Philco 48-482 Output transformer Posted: May Sat 05, 2012 12:26 pm |
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 13632
Location: Utica, NY 13502 (USA)
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The AES transformer is push-pull. I wonder if it can accept the unbalanced load of a single-ended circuit or if "universal" transformers are designed for this.
I did find a suitable transformer but, in discussing this via PM with Stan, it seems his transformer has a tapped secondary for the feedback loop. Perhaps there was a circuit revision?
Thanks for the link to the clean copy of the service bulletin!
EDIT: Stan checked again....no tapped secondary.
Dave
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