Topband: Hi-Pass filter for 160 to reject BC Band

[Eddy Swynar]

On 2012-01-08, at 11:17 AM, k8gg at voyager.net wrote:

> Charlie, W0CD, found he could spread a coil or remove a turn to "customize" the rejection for local stations.  Although we do not have an actual filter-response curve, we were able to move F4 up to 1400 KHz to nul a
> local broadcast station just over a mile from my QTH, which seemed to also move the start of the attenuation closer to 1.8 MHz.  

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