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Examining AM BC OV

I live close to the local AM BC TX. Right from the start, I had to add filters. Now I am looking closer. Keeping in mind that my active loop antenna has gain, here are the approximate signal levels that the kiwi is subjected to without a filter.

950 KHz 0 dBm
1280 KHz -5 dBm
1370 KHz +5 dBM

My method was to use a nooelec AM band reject filter which is -40 dB across the BC band and to read the result on one of my kiwi receivers. Adding the 40 dB to the kiwi level yields the above levels. Next is to consider is the gain of the loop and see what the FCC says is the uV/M footprint and see if it makes sense.

In the meantime, I am building a new compact notch filter assembly to replace my original.


  • The three stations involved are all 5 KW or less and have daytime/nightime patterns. They are 2.5-3 Km from me with FS of 300 mv/M @ 1 km or greater. The 50 KW Class A station is further away thankfully and does not cause issues
  • a little humor..... I have both WHAM and WACK nearby but neither cause problems :-)
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