ZW transformer

Here is one explanation and a Hum Fix.

Having done this, I can confirm it works. Did it 4 years ago to a ZW and still dead silent.

Tranz4mr’s ZW Page 

Whoa!!! That's some website, umm, "design."

If it's not an "R" model, it can still be fixed to be perfectly quiet. While your in there check/replace the rollers. Very easy to do.

Chris

@caa posted:

If it's not an "R" model, it can still be fixed to be perfectly quiet. While your in there check/replace the rollers. Very easy to do.

Chris

Hi Chris, by perfectly quiet I assume you’re meaning absolutely no 60 cycle hum with the older laminated core. I have never been able to totally illuminate the hum from a hummer coil. I can reduce it to a very acceptable level but never totally eliminate it. Could you tell us how you do it or show us pictures of how you do it. I’m sure many forum  members would appreciate learning how you do it. Thank you much, Jim

I would be interested as well.

John

OK, I discovered this by accident. Mine was very loud. What I was trying to fix though was the A and D handles would not go to zero voltage. This is because The coil had shifted to the back, towards the terminals. Probably dropped.                                                       To get the rollers off the coil I had to move the coil. There is a tab at  the coil. Part of the alu. brackets. It is in the center of the bottom of the coil. About 7/8" square. I removed the two brass colored clamps at the top. I then pushed/forced the coil toward the terminals. I bent the 7/8" tab in towards the coils to help keep it in the correct position.                                                                             Then I bent the two brass clamps a little bit. So as to keep the two alu. plates tight. In doing this I corrected the throttle rollers to rest off the coil. When I put the top back on I was pleasantly surprised it was now also  very quiet. Yes you can still hear  a hum, but just barely.

Chris