[R-390] Filter repair

[quartz55]

I've been working on the 2K filter today and have some pictures, although I'm not done with it yet. It takes forever to work on a side and glue wires together and repeat the other side. Plus working with the headband magnifier that I have to get up to about 3" to what I'm working on. I'm thinking about getting a pair of the  3.5 diopter surgical loupe so I can get back from the work a bit. Anyhow here's some pics. I cut the mounting studs off, plus the mounting wires to make it fit in the tube. Removed the plastic cover, but that was a given since I had to repair the filter anyhow. On the end view you can see where I glued the bobbin in the copper cup, glued the #40 wires to the soldered side of the connecting wires and the header connectors, added a ground wire from the outside end of the ground and put a small piece of shrink tubing so nothing touched, glued that in place, glued the new fishpaper in place along with the filter body to the tube. Hopefully this thing will still work when I get done with it.

The 4K filter seems fine, I just need to solder up the ends. I did get the skirt measurements down to about -40db. If I can get an amp on the output side of the filter, I may be able to get to 60 or 70 db if I'm lucky. I'm thinking about a LM384 or an fet op amp.

http://i251.photobucket.com/albums/gg287/DogTi/R390A/2kfilterassy2_zps00662ee6.jpg

http://i251.photobucket.com/albums/gg287/DogTi/R390A/2kfilterbot_zps67ec03c8.jpg

http://i251.photobucket.com/albums/gg287/DogTi/R390A/2kfilterassy_zpsf8c9fb21.jpg

http://i251.photobucket.com/albums/gg287/DogTi/R390A/2kfilterassy3_zps57ea1649.jpg