Need 50L6 output xfmr

[George Maier]

Hi Paul:

Thanks for your thoughts and suggestions; very good info.  I'd been
considering a more normal transformer, but thought I'd try finding a closer
match first.  

Thanks to info supplied by Steve in Tuscon, I learned that Radio Daze offers
a transformer that's nearly a perfect match, and at a reasonable price.  
http://www.radiodaze.com/RD-transformer01.htm

I guess you know what my next move is.  Once the replacement is installed,
I'll run a distortion test with my Sound Technology 1710A through a sig gen
just see how the old radio does perform.

Thanks again and 73,
George - W1LSB
(SBE CPBE)


-----Original Message-----
From: Paul Litwinovich [mailto:paull at wshu.org] 
Sent: Friday, September 10, 2010 9:39 AM
To: George at MaierGroup.com; BOATANCHORS at LISTS.TEMPE.GOV
Subject: Re: [BOATANCHORS-TEMPE] Need 50L6 output xfmr

I've seen these before. hard to find, but you really won't notice the 
difference if you put the B+ straight to the screen and use a conventional 
output transformer. I had to do that once on a similar model. They feed the 
screen with the audio 180 deg out of phase but low level, just enough for a 
little gain reduction which produces less distortion, just like using a 
feedback network on an AM modulator. We are talking about what you could see

with a good distortion analyzer, not something that you will likely notice 
with your ears. You can increase the cathode resistor by a step or two and 
accomplish the same thing.

Paul A. Litwinovich
Director of Engineering
WSHU AM&FM WSUF FM
PG-GB-039245
N1MUC


----- Original Message ----- 
From: "George Maier" <George at MAIERGROUP.COM>
To: <BOATANCHORS at LISTS.TEMPE.GOV>
Sent: Thursday, September 09, 2010 11:30 PM
Subject: [BOATANCHORS-TEMPE] Need 50L6 output xfmr


> OK..so I was strolling around the last MIT flea market in Cambridge, and
> spotted a really cute little RCA 65X1 AM radio, ca. 1948. It's a classic 5
> tube all American AC/DC design, with a brown Bakelite cabinet. The kind of
> thing my XYL would actually like on the bookshelf (I tried a Zenith TO,
> didn't take too well).  Of course it followed me home.
>
> The good news: it's very clean, all original, and complete; even to the 
> pins
> that hold the pressboard back cover in place.
>
> The bad news: the audio output transformer is open - oops!
>
> Does anyone have a spare vintage output xfmr hanging around? 
> Unfortunately,
> it's not a garden variety single ended output XFMR. The B+ is fed through 
> an
> off-center tap, with the remaining leads going to the plate and screen.
>
> Thanks for the read...
>
> 73, George - W1LSB
 

__________ Information from ESET Smart Security, version of virus signature
database 5435 (20100908) __________

The message was checked by ESET Smart Security.

http://www.eset.com
 

-----------------------------------------------------------
This list is a public service of the City of Tempe, Arizona
-----------------------------------------------------------

Subscription control - http://www.tempe.gov/lists/control.aspx?list=BOATANCHORS
To post - BOATANCHORS at LISTS.TEMPE.GOV
Archives - http://lists.tempe.gov/archives/BOATANCHORS.html