The design based on the article for the 80 meter filter does work but it's such a narrow band pass that you'd probably have to build 3 different filters and tune them each to 1/3 of the band with a little overlap to cover the 80m band. I didn't need the 160m filter so I didn't build that one. The 40, 20, 15 and 10m filter work great. I verified them once tuned on a friend's network analyzer with tracking generator and they passed with flying colors. With only a slight adjustment of the windings once everything was in place and connected through my RigExpert antenna analyzer and to a dummy load, I now have 4 of the 5 filters that I built and working perfectly. Using the GDO and then verifying the he resonate frequency with a loop of wire to my frequency counter, It got me so close when tuning the LC pairs. I REALLY enjoyed using it for that project. I bought a used but in excellent condition Millen 90651 GDO off of eBay. I used the K4VX article from 1988 which calls for the grid dip meter. I wanted to build a set of the basic band pass filters for field day ops and didn't have a network analyzer.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |