[RFI] Locating Noise - Radiated or Conducted and then radiated

Pete Smith n4zr@contesting.com
Tue, 04 Jun 2002 14:54:29 -0400

At 06:14 PM 6/2/02 -0500, you wrote:
>Now to find someone in Fort Worth Texas with an MFJ-852 noise receiver to
>hunt further with.  Has anyone used this device ($99) from MFJ or found it
>useful?  How close to an arcing pole hardware do you have to get to hear
>it - or conversely how far away can you hear arcing pole hardware at 136
>Mhz?  My AM radio hears things for way too long a distance to be very useful

The MFJ unit is very well regarded by a friend who is an RFI pro, though he 
says it could use a directional antenna and an attenuator (now it uses a 
telescoping whip for both).  You need to be reasonably close to the source 
to get an indication at 136 MHz.  You may find a portable shortwave radio a 
useful intermediate option, operating at 30 MHz or so, to get you within a 
couple of poles.  You can use your body to shield the whip on either the 
MFJ or an aircraft band radio to get some better directivity.

I bought a little IC-Q7A duo-band handitalkie at Dayton this year, because 
it also does AM receive up to 375 MHz or so, in addition to 300MW on 2m and 
440 fm.  I plan to build a small moxon rectangle antenna to use with it, 
and figure out some sort of attenuator (doesn't need to be 
calibrated).  For under $100 (AES Dayton price) I think it is a definite 
improvement on the MFJ.

73, Pete N4ZR

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