80m band pass-filter : Coils fabrication

80m bandpass filter simulation



29µH ---- 68 pF ---- 68 pF ----58 µH ---- 68 pF ---- 68 pF ---- 29 µH
                           680 pF                                        680 pF
                             gnd                                              gnd

This should look like :



Now, the coil fabrication (same method as for the 40m bandpass filter !!!!!!)


































Once again, exactly 29.00µH and 58 µH, HI !!!!

I decided later on to replace all PTFE wire by a good enamelled copper wire, 1mm diamter for the 40m coil, and 0.5 mm for the 80m coils (you can see that the 29µH coil picture already uses enamelled copper wire, HI !)

Next step : Place both filters together, and see what happens !

Ronan