langevin am16 trays
« Reply #20 on: May 28, 2005, 12:25:52 AM »
As luck would have it, I pulled out the lam with the E-shields soldered to it. I had a fifty-fifty chance, so naturally...

I did manage to realize the errors of my ways, and managed to unsolder the shield wires before they could snap like a dry twig in a stiff desert wind. Darn, this is an L lam also. I was hoping for a different shape, like a 31DU or something. But......

 here are the two L-31 lams side by side. Yes! There is a difference!

Obviously a different material, which is the reason for the variation in B-H curves. The earlier lam is on the left.
I am going to send both of these to the Good Doctor at Mag Metals so I can get the low down.

The funny thing is that both transformers gave me the same inductance readings when tested, but the curves were way different. I did get one difference in an inductance measurement with a Sencore bridge when measuring the inductance of the full primary. Weird.

I put both lams thru a bobbin wound with about 2000 turns on it to see if I could detect a difference. The bobbin had about 50 mh with just air for a core, and 586 mH with just one lam inserted. Both lams gave the same 586 number, so it will be interesting to, see what the difference is. Maybe some type of annealing difference.


I soldered the can back together so I could try out my DIY LAngevin circuit board with some vintage iron:


If I can't fix it, I can fix it so nobody else can!
Frank's Tube Page: www.mif.pg.gda.pl/homepages/frank/vs.html
Guitar Amps: http://bmamps.com/Tech_sch.html


langevin am16 trays
« Reply #21 on: May 28, 2005, 12:29:51 PM »
totally cool, CJ....

Please, tell me you are kidding about the hash oil content of the transformers... You could get arrested for carrying these old iron.  :green:

Anyway, if someday you get crazy enought for doing it, I would love to see the output transformer, TF-324, breaking apart and showing the windings to The Lab.

Go, CJ, go  :thumb:


langevin am16 trays
« Reply #22 on: May 29, 2005, 12:10:15 PM »
So..........for the TF-425-A.......the A stands for Afgan?  :roll:


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