The AM Forum

I've got one of those big Johnson rolling "edge-wound" inductors - a model 226-2. Not technically a "roller" inductor, since the roller is actually a sliding contact. It's in excellent condition, but the plating could use a little cleaning. An old Johnson/Cardwell catalog describes it simply as "plated", but doesn't specify what sort of plating it is, though it looks like it might be silver. Has anyone tried cleaning one of these? I'm thinking I might try brushing on some of my wife's silver jewelry cleaner (not abrasive), but I don't want to risk damaging the plating. I've also got a similar B&W inductor that also looks like silver plate.

Scroll thru this thread:

https://forums.qrz.com/index.php?threads/w7tfo-hints-kinks-fear-loathing-in-the-land-of-engineering.525303/

Amongst my other items, I have a write-up on just such a restoration.

73DG

Thanks - I will check that out.

And...why is it always my luck that there is a arc spot right exactly where I need to be, such as 3870, 3885 etc.... >:(

Very cool - thanks. Just so happens that I've got a bottle of Tarnex handy.
The catalog says "...handle well over a kilowatt of plate modulated RF energy to 30 Mhz". I wonder if that means a 250 watt carrier modulated 100%, or a 1000 watt fully modulated carrier? It's a pretty robust coil.

That would be a kilowatt I put, appx 700 watts carrier and 2.8kw pep or so.

Think of it as a roller for a desk kw.


--Shane
WP2ASS / ex KD6VXI

GLOVES.
Definitely use gloves with "Tarnex".
Also rinse with a solution of baking soda... it's an acid.
Followed by clear water...

               ymmv.

                             _-_-bear

Yes, very good idea. Many years ago, when I was into boats, a local boat shop recommended a powerful cleaner for me to use to clean a corroded brass air cleaner. I bought a bottle, and it worked amazingly well, but that brass part smoked in the solution. The cleaner was basically pure acid. Nasty stuff.