[R-390] Filter Repair

[quartz55]

Finally got back to finishing some repairs after my back surgery.  Finished the extra 4K filter, I broke one of the magneto wires and had to repair that, fixed the coils and replaced everything and got this response.  http://i251.photobucket.com/albums/gg287/DogTi/R390A/4K2filter_zpsd0ca77b6.jpg

It looks a bit narrow on the high side and may be out of spec as far as the min/max variation.  I don't know how to read the info in the filter data sheet.  I'm looking at 'Filter Response' part, it lists freqs as F6H-F6L, and F60H-F60L as well as 20 and 40.  I only have the data sheet for the 2K filter.  Bottom line is I'm wondering what the variation within the bandpass portion is supposed to be.  This filter appears to have about 7 db variation in the bandpass.  I have no clue what it originally did since it was not working when I got it.  Insertion Loss with this filter is 25.5db.

I'm thinking I'll sell this filter to fund some items for the test setup.  I still can only get to about 36db before I run into feed through.   It's probably the setup, not the filter, but I need to make sure.  I'm going to try a FET input amp to see if I can boost the output of the filter into the Moto (Boonton) meter.  I'm already pumping about a volt into the input.

Next project is to remove and 'fix' the 8 and 16K filters although they are still working, but I bet they have leakage and will affect the AGC.  I might as well since I already have 2 of the filters and the switch assembly apart.

N3DT