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" <[email protected]> To: "Topband" <[email protected]> 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 _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
