Topband: Locating Problem Signals

[donovanf at starpower.net]

Simple TDoA techniques are useful for direction finding on 
non-ionospheric propagation modes, but TDoA-only DF techniques 
are very unreliable for ionospherically propagated signals 


A recent example is the intruder that was continuously active on 
14.000 MHz for several days. Operators on the Kiwi TDoA 
network were convinced that the intruder was definitely located in 
Indiana. The Kiwi DF network was off by more than 1000 miles... 


An informal network of hams using simple 20 meter Yagi 
was much more accurate. 


73 
Frank 
W3LPL 


----- Original Message -----

From: "Dick Bingham" <dick.bingham at gmail.com> 
To: "Topband" <topband at contesting.com> 
Sent: Saturday, February 9, 2019 5:19:06 PM 
Subject: Topband: Locating Problem Signals 

If I remember correctly, there have been requests here for folks to listen 
to an offending signal so its location can be determined. 

There is a fairly inexpensive way to accomplish this task using a ~$200 
"0-to-30MHz SDR" called "Kiwi". One of its operating modes includes TDoA 
measurements using multiple Kiwi's located around the USA/world. 

Check-out ==> *https://valentfx.com/vanilla/discussion/1196/tdoa-extension-operating-notes#latest 
<https://valentfx.com/vanilla/discussion/1196/tdoa-extension-operating-notes#latest> 
* 
and ===> * http://kiwisdr.com/ks/using_Kiwi.html 
<http://kiwisdr.com/ks/using_Kiwi.html>* 
You can use one of these Kiwi's by checking here ===> 
*http://kiwisdr.com/ks/using_Kiwi.html 
<http://kiwisdr.com/ks/using_Kiwi.html>* 
Contact me off-line if you want more info. 

73 Dick/w7wkr at CN97uj 
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