I noticed a bit of BC inter-mod so built a 9 pole Chebyshev high pass filter dead bug style in a small diecast box with some internal screening made from double sided pcb stock. I designed it with the excellent RF filter design package from Iowa Software, and used an LC meter to get the capacitor and inductor values correct. Only took a couple of hours to make out pf the junk box using polystyrene caps and small toroids - designed for 50 ohms with corner frequency 1.5MHz and 0.2dB passband ripple.
http://iowahills.com/9RFFiltersPage.html The filter response was almost exactly as the design showed, as measured on the G4AQG spectrum analyzer - at least 50dB down at 1 MHz and a local broadcast station on 693kHz station is now almost undetectable compared to 70dB over S9 or more without the filter. Inter-mod has gone. Jeremy G3XDK/G4AQG > On 3 Mar 2016, at 15:59, Roger White <[email protected]> wrote: > > Anyone have a BCB High Pass Filter that they would recommend? Seems like > there were a number of sources for these a number of years ago, but Google > only came up with a few now. > > Roger White W5RDW > Murphy, TX > _________________ > Topband Reflector Archives - http://www.contesting.com/_topband _________________ Topband Reflector Archives - http://www.contesting.com/_topband
