[R-390] Filters

[quartz55]

The Oenohilia Private Preserve Wine Preserve sounds like it may work about as good as anything I can do, and since I've got another filter to do yet, I may buy a bottle.  $9 including shipping now.

I've made up a form with a piece of teflon wire insulation wrapped in painters tape to fit and center the wire in the cup.  Now to figure out how to weld the wire on the resonator.  I did try some pieces of fine wire, strands cut out of some #24 stranded wire.  I have a 61000uF 55V cap I charged up to 10 volts and welded them onto a bolt I had about.  10V seems to be about the max, if I go higher, the wire starts turning red for about 1/4" from the weld and comes apart.  I was just using a variable PS to charge the cap, and clip leads with a small flat grip clip for the wire.  Now to figure out how to do this proceedure on the unit and the form with the wire in it.  Seems best results were to hit the wire on the end and immediately let go with the clip so as not go keep heating the wire, but the voltage has dropped way down pretty quick.  It may not matter.  I had welds good enough to pick up the 3/8x2" bolt and nut with the strand.

Here's what I'm dealing with. http://i251.photobucket.com/albums/gg287/DogTi/R390A/filterwireform_zps94a11e37.jpg  The length of the caliper end is the depth of the cup to the resonator.  It looks like if the wire gets welded on the resonator right, it should just come to the end of the bobbins, and that is what the other end does.  I'm not in a big rush.

I'm still thinking about the donuts. I don't quite understand your method Tisha.  I don't have any Teflon tubing, but I do have small pieces I can cut 1x1" squares out of, it's about 0.025" thick.  The paper in the filter is about .006" thick.  Since I don't seem to have any problems with resistance from the bobbins to ground I could just re-use the paper.  I've cleaned everything up with alcohol but there are still a few pieces of junk between a few of the resonators, I can get that out with caned air.