[1000mp] Re: INRAD Roofing Filter Performance

[Thomas Giella KN4LF]

The INRAD 70 mhz IF roofing filter addition is for discerning DX'ers and 
contesters not casual operators. The mod. narrows the frequency range that 
slams the first mixer down from 12 kc to 4 kc.

If you have several 5-50 kw AM broadcast band stations nearby like I do then 
the 4 kc constriction will knock out allot IMD crud on 160 meters. If you 
are a phone and/or CW contester and are competing with dozens of other high 
powered stations say like on 160 meters, the 4 kc constriction also kills 
allot of IMD crud and  you therefore hear the station you want. Same with 
being a DXer fighting the pileup on 20 meters to VU4.

But for the average operator though you will probably not notice much 
difference.

Also one thing I discovered was that my high Q 5 foot diameter outside 
mounted coaxial magnetic loop knocks out IMD crud even better than the 
roofing mod.

73,
Thomas F. Giella, KN4LF
Retired Space & Atmospheric Weather Forecaster
Plant City, FL, USA
Grid Square EL87WX
Lat & Long 27 58 33.6397 N 82 09 52.4052 W
kn4lf at arrl.net

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