[Elecraft] [K3] Using K3 for relative noise survey

[Jim Brown]

Thanks Jim.  I live out in the country, at least 30 miles from any high 
power AM BC, so haven't had this issue or evaluated that important 
capability.  The little FunCube Dongle Pro+ also has filtering, but I 
don't know how good it is. It covers only 192 kHz at a time, but is 
16-bits, so has greater dynamic range. The SDRPlay RSP2 is probably more 
useful, thanks to its greater display bandwidth.

With any of these radios, N7WS's calibration method (or something like 
it) should be used. Another suggestion -- take your test setup to a spot 
in the middle of nowhere -- no buildings, no power lines, no solar or 
wind arrays -- and look at the noise floor there. Save those data as a 
reference -- that's your objective at a new QTH.

Also, look around the area, and apply common sense. Are there houses? 
Farms? Businesses? Radio towers? Cell towers? All are likely to have 
dozens of noise sources, either now or in the future. My applications 
note on chasing RFI talks about many of them.

73, Jim K9YC

  On 8/1/2017 10:21 AM, Jim Miller wrote:
> I have an RSP1 and it works well with the free software available to 
> do spectrum work. I particularly like HDSDR's ability to make long 
> term recordings.
>
> However I found it of limited use on 160m due to AMBC interference 
> since it doesn't have much (or any?) front end filtering. I'm 30 miles 
> north of Baltimore where the AMBC originates.
>
> I put a brickwall filter in front of it and it worked very well 
> afterwards.
>
> I've recently bought an RSP2Pro which has better filtering in it which 
> I hope will eliminate the need for the external filter. I haven't had 
> time to even plug it in yet.