Eddy VE3CUI wrote: >Hi George, > >I'm curious as to how the results might compare, if one were to simply place a >series-connected coil & capacitor wave trap (resonant to the BC station's >frequency, of course) to ground at the receiver input...? Was that tried prior >to the inclusion of the high-pass filter? > >The wave trap could be made even more effective if one were to place a second >parallel-tuned trap in series with the antenna lead, and installed between the >receiver & the series-tuned trap... > >~73~ de Eddy VE3CUI - VE3XZ
Hi Eddy You are correct, but obviously this is not the best approach for multiple broadcast stations. When I first built my remote station there was a high power AM station with an 8 element array beaming straight at it from about 1km away. This made receiving difficult as it was inducing literally volts onto my 260' vertical. I built a simple elliptic function filter with a null at 790kHz and high pass-band ripple. This provides better than a 60db null across the modulated bandwidth of the BC station and negligible attenuation on 160m - but very variable attenuation across the remainder of the broadcast band. The filter has only 3 capacitors and one inductor. I think this is a better approach than just a series tuned circuit as all parameters (including the necessary filter complexity) are under the designer's control. Now the other BC station has closed down and I have no AM stations within 150km - by far the best solution! 73 Roger VE3ZI _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK
