OEP trafo shielding
« on: September 02, 2004, 09:38:31 AM »
I have a quick question about shielding the OEP trafos for a G9 with the OEP mu-metal cans.  I assume I just solder the top and bottom together and then solder the bottom to the ground lug on the trafo?  Can I just "tack weld" them together or do I need to solder the whole perimeter?  Anything else to watch out for?

Regards,
Chris


Jazzy_Pidjay

OEP trafo shielding
« Reply #1 on: September 02, 2004, 09:55:44 AM »

Kev

OEP trafo shielding
« Reply #2 on: September 02, 2004, 05:00:29 PM »
I use a file to prep a small surface area/section to get the solder to stick.
Some of the other guys talk about using additional flux.

no real bad experiences but
perhaps ... be careful not to over heat the sheiling pin.
take care and good luck.
Kev
DIY Factory

OEP trafo shielding
« Reply #3 on: September 02, 2004, 11:17:43 PM »
Thanks guys.  I suspected it might not be straight forward.  I lightly fluxed the perimeter of the cans and bottoms with an acid paste plumbing flux.  They took solder from my 15 watt iron just fine.  I did the tinning of the mu metal without the trafo installed to avoid overheating.  After tinning I washed off any residual flux.  I then popped the trafo in and was able to solder bottom/can/shield pin in a few secconds.  Nice and tight seal!

Regards,
Chris

mathflan

OEP trafo shielding
« Reply #4 on: February 09, 2006, 11:52:54 AM »
Hi,

O my G9 board, I have soldered and put the screens cans of the A262A3E with no problems but I don't arrive to solder the A262A2E with his screens cans, the pins are shorther than the A262A3E.

How did you manage to put the A262A2E on the board
 :?:

Do I have to Remove the bottom plate of the can??

thank yo

mathflan

OEP trafo shielding
« Reply #5 on: February 09, 2006, 04:04:26 PM »
I tried to put the OEP A262A2E with the Screens can but still have very small pin to be soldered on the board:




I Solderer the bottom plate and the box shield of the screens can together and sand them :





I Think that I will remove the bottom plate... :roll:

matta

OEP trafo shielding
« Reply #6 on: February 09, 2006, 04:15:04 PM »
You can't remove the plate...

If you do you may as well not have the screen can then as it will be floating and sealing it offers better isolation from interferance., it needs to be sealed... and the screen pin one needs to be ground to the can, like you have done...

You have also soldered the plate right on the top of the can. I find it easier to push the plate inside the can and leave a 2 mm gap.

What I would do is desolder the screen pin, use a pair of needle nose pliers, gentle pry the trano up towards the can and then solder the screen pin.

Looking at those photos it seems you have at least 2 mm there, which will help you lengthen the trano pins.

Cheers

Matt
Matt Allison
www.matt-allison.com

Quote
We are not going to start thinking of ways to get an octopus to commit a crime, cause that just has failure written all over it – Earl J Hickey

mathflan

OEP trafo shielding
« Reply #7 on: February 09, 2006, 05:06:06 PM »
thanks matt for the anwser.

Quote
What I would do is desolder the screen pin, use a pair of needle nose pliers, gentle pry the trano up towards the can and then solder the screen pin.


I tried that but I m at the maximum.

Do you think I can just solder the plate to the can at only one point instead of solder all around the can??

CJ

OEP trafo shielding
« Reply #8 on: February 09, 2006, 06:25:45 PM »
Yes, that would be fine. Some companies use nothing, just a press fit and some potting compound, so you will be one step ahead with just a couple of tacks.

Peerless used four swedged welds on a lot of their stuff.

Don't aggrevate the mu metal, that is the important thing.
Bending it etc. Don't know about heat.
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

mathflan

OEP trafo shielding
« Reply #9 on: February 09, 2006, 07:31:24 PM »
Ok , thanks cj


I will try to win 1mm so as to be able to solder the transfo on the board...


Viitalahde

OEP trafo shielding
« Reply #10 on: February 10, 2006, 02:26:23 AM »
I generally apply some of that sticky flux stuff all over and start soldering, helps a lot.

guitarguy12387

Re: OEP trafo shielding
« Reply #11 on: September 05, 2009, 01:25:27 AM »
Let me preface this with... i'm an idiot haha.

So i have been trying to take my time and solder the can together. And apparently i got it a little too hot on accident and started to melt the plastic on the tranny  :'( I just noticed a little bit of the black coming through the corner of the can. My question is: is this detrimental? Do i need a new tranny?

Thanks!

lolo-m

Re: OEP trafo shielding
« Reply #12 on: September 05, 2009, 03:09:56 AM »
Let me preface this with... i'm an idiot haha.

So i have been trying to take my time and solder the can together. And apparently i got it a little too hot on accident and started to melt the plastic on the tranny  :'( I just noticed a little bit of the black coming through the corner of the can. My question is: is this detrimental? Do i need a new tranny?

Thanks!

You burnt the plastic can but your transfo is maybe still good. To know here is a simple way:
Check the continuity on each winding.
Check if there's no short between the legs.
Try to measure their resistance. They should be quite the same on each pair ( there's a pair of primary windings and a pair of secondary windings ). Allow 5 to 10% un-matching. If the pairs match, your tranny is certainly OK... But if they don't, you may have burn your tranny  :'(...

PS: If you have another one, compare the results, you'll know if your tranny is OK.
Hard to be a punk... But sometimes you have to...

s2udio

Re: OEP trafo shielding
« Reply #13 on: September 05, 2009, 06:19:19 AM »
You really don,t have to solder the trannie all the way round.....!!....a couple of tacks is
quite sufficient.
On the end of a Rural Twisted Pair.

guitarguy12387

Re: OEP trafo shielding
« Reply #14 on: September 05, 2009, 09:31:48 AM »
Quote
You burnt the plastic can but your transfo is maybe still good. To know here is a simple way:
Check the continuity on each winding.
Check if there's no short between the legs.
Try to measure their resistance. They should be quite the same on each pair ( there's a pair of primary windings and a pair of secondary windings ). Allow 5 to 10% un-matching. If the pairs match, your tranny is certainly OK... But if they don't, you may have burn your tranny  ...

PS: If you have another one, compare the results, you'll know if your tranny is OK.

Ohhh okay. Phew. Thats what i figured, but just wanted to make sure. I'll check everything before i tie it to the board.

Quote
You really don,t have to solder the trannie all the way round.....!!....a couple of tacks is
quite sufficient.

Hah yeah... reading this thread now (after putting it together) i see that haha. Next time... Thanks!


 

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