The AM Forum

Hello and Happy new yr. I picked up a thordarson t-19c45 choke at hamfest, Been looking on www for information but no luck. Can anyone point me in right direction where to look up values on this? thanks kr4wi Matthew

Try this. Lots of Thordarson catalogs you can look through:

http://www.bunkerofdoom.com/xfm/index.html

According to my Thordarson catalog...it is listed as a T-19C45 and is a smoothing choke. 12 HY @ 500ma. 75 ohms dc resistance and 5000v rms test volts.  It is the largest of the "19" series chokes and matched the T-19C38 swinging input choke.

Thank You, Pete, and Dave. I did find it in one of those catalogs Pete. Thank You Dave for the specs. It was in the 1942 catalog. It cost 18 bucks in 42, that was alot. Thanks agn. Matthew KR4WI

Yes, I did Pete: I even looked around while I was on the browser. I found out the art-13 used 811s not 811a I didnt know that, I am building power supply for that rig at the present time. Again Thanks allot Matthew KR4WI

Thordarson changed their part numbers periodically.  Every couple of years they would come out with a new product line with completely different numbers.  You need to have a complete collection of old catalogues to be able to look up  all the numbers you may find.  Usually most of the new products in a line were identical to one in the older product line, but Thordarson did not offer a cross reference..

Never could figure out why they did that.  On the other hand, UTC sometimes changed the specs of product entirely, but kept the same exact number, particularly in the LS series.  For example, there is a LS power transformer that originally had 2.5 volt filament windings.  A later version with the identical LS number has 6.3 volt filament windings.  The turns ratio of the LS-49 class B driver transformer was  changed just before WW2.  Many of the newer versions of LS transformers are rated for lower power levels than the earlier original versions.

I have found that the fine folks at Thordarson are always willing to help you with the specs of any of there products, regardless of age.  I found at a flea market a very large thordarson modulation transformer with a p/n matching nothing in any catalog I could find. They identified it as a commercial tranny made for RCA, that modulated a pair of 813's with 805's and it even had a screen winding! Rated 350-400 watts. Not a bad buy for $10 !!

anyway, you can look Thordarson up on the web and call the phone number. Very nice folks!

Ronnie