[R-390] Filters

[quartz55]

The needle thing would probably work if the wire didn't weld itself to the needle.  I am thinking about making a sled arrangement for the Teflon wire shield/painters tape assembly to slide the whole assembly including the wire into the copper cup while the + clip is attached to the tiny wire.  I just don't have any access to tiny glass tubes and I still would have to put the wire through it and get it centered.  It needs a jig to assemble and weld at the same time.  It's impossible to do by hand, at least for me.

In the meantime, I've cut out some foam PE from the hardline and was not impressed with it's temperature resistance.  I put the butane flame on it and it melted and caught fire.  However 2 layers of the stuff seem to make a good spacer. This is just a rough attempt.  I doubt if it would disintegrate like the original stuff.     http://i251.photobucket.com/albums/gg287/DogTi/R390A/filterfoamPE_zps38cb6c27.jpg

It's a bit stiff, but it certainly has high resistance.  I may try putting it in a tube and soldering next to it to see what it does.  Actually where it sits in the outer tube is about a half inch away from the ends.  Some judicious use of water soaked towels may do the trick, not unlike the label.  Maybe I could also make a ring of Teflon around the perimiter to help keep the heat away from the foam and forget about the card material.  But the card would sure make it easy to slide into the outer tube.  Actually my pieces of Teflon may work like the card material, I'd just have to make strips instead of a solid tube.

I re-read Graham, G8OAD's article and once I've taken a filter apart, it makes a lot more sense.  He answers a lot of questions if you read it carefully.  I'm thinking about forgetting the tape around the magnets, mostly because I don't have any.  The magnets are attached plenty good, I can't imagine tape is going to help.  I do have some mylar tape I could put over it.