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Messages - KaySeeks

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916
General Radio Discussion / Re: H.R.5709 - Pirate Radio Act
« on: July 24, 2018, 2314 UTC »
"between 535 to 1705 kHz or 87.7 to 108 MHz"

Cat's outta the bag now. This will be used in court to protect hf piracy.

Again, the new act does not renounce The Communications Act of 1934; it simply strengthens the penalties and fines for operating in the AM and FM bands. It does not say that HF pirates are now, all the sudden, acceptable.

I'm not sure why you say it will be used to "protect" HF pirates.

917
Finally got around to checking for this. I have it.

2220 UTC - Music mix
2228 UTC - SSTV
2230 UTC - "Bye Bye" in computer-generated voice.

918
Hmm... Might not be European?

919
2143 UTC - "The best rock from the last forty years, Zenith Classic Rock".
2155? UTC - Pink Floyd, "Shine on (You Crazy Diamond)".
2207 UTC - Led Zeppelin, "Trampled Under Foot".
2246 UTC - Rush, "Closer to the Heart". Signal is fading down here.

920
Good signal SINPO 43343. Mark would be better if there wasn't a carrier 4 KHz above.

2050 UTC - late-60s music.
2058 UTC - Billy Bremmer, "Loud Music In Cars"
2059 UTC - Beach Boys, "Good Vibrations".
2115 UTC - "Chansons d'Amour".
2117 UTC - Alice Cooper, "School's Out (For Summer)".
2128 UTC - Flock of Seagulls, "I Ran (So Far Away)".
2136 UTC - Checked back and carrier is gone.

921
QRM on the LSB. Listening on the USB only.

2050 UTC - Funky dance music with occasional breaks in the audio.
2100 UTC - The signal is weak. Tough copy.
2111 UTC - Checked back and carrier is gone.

922
SINPO 45555.

2018 UTC - Pro-sounding ID announcement, "From the Paul Jonkers (?) Studios in Brussels, live and direct, this is Johnny Tobacco."
2041 UTC - "Johnny Tobacco, live and direct from the Paul Jonkers Studio in Brussels." Continuing with Dutch songs.
2113 UTC - Checked back and carrier is gone.

923
Presumed. Usual programming.

Getting killed by UTE QRM on 6286-6289 KHz now at 2015 UTC. Listening to the LSB only.

ID at 2016 but too much noise to understand it.

924
S9+10 dB. SINPO 54555.   LOUD.

925
Weak but very much in the clear. SINPO 24422.

2003 UTC - John Lennon, "Power to the People"
2005 UTC - Announcements.
2138 UTC - Still on the air but signal is very weak. Can't really tell what is being said.

926
If the kiwis would employ vertical antennas, it would help the tdoa work with regards to skywave.

If the pirates employed more NVIS, it would make it more difficult too.

927
50 or even 25 miles of accuracy (typical with skywave HF signals) is not going to uniquely identify anyone. 
You are doing well if you can repeatably locate an HF signal that isn't from some 10+ kW transmitter to within those distance ranges. I haven't been able to do that well generally. That Link11 signal on ~6942 KHz we have been talking about in that other thread is an exception and is a very strong signal.

Some operators dislike the fact that now their general location (Chicago vs Boston for example) will be known, however. There's no changing that now. And to be honest, that's been possible previously without TDoA.
Right. For example, ways of doing this include: 1) looking at propagation characteristics and also 2) sniffing around with the many receivers on the internet.

928
If the software attempts to find multiple features and time each of them, then it is less likely to plot only a single transmitter, but rather might indeed plot combinations of both transmitters, resulting in junk.

In fact, I was wondering about exactly this so I attempted to "find" WWV on 5 MHz, 10 MHz and 15 MHz with receivers on the west coast of North America in the presence of WWVH (and passband narrowed to ~100-200 Hz so that differences in the male voice on WWV and the female voice on WWVH were reduced and the focus was on the carriers only). I don't have the results available right now but let's just say that things became "confused". It seems to me that as a general principle with TDoA, anytime there is a significant amount of skywave propagation present, the derived result varies quite a bit over time (see more on this at the bottom of this post). In this case, this was worse than I expected. I suspect (but was not able to prove beyond a doubt) that the presence of WWVH confused the algorithm.

Could it be used to find the ham jammers?  Maybe, but remember what I said about the 30 second samples.  Transmissions from multiple stations, even if one at a time, that have handoff times inside that 30 second window will likely mess with the system.  So if the jammer does not stay on the air for the entire sample time that will probably result in errors, jumbled combinations of the data for the jammer and jammed stations.

There has been some discussion about allowing for sampling intervals shorter than 30 seconds for reasons like this.

Getting back to what I mentioned before, skywave propagation is a big confounder here - it will cause a fair amount of variation from location attempt to location attempt. (This makes sense to me as the ionosphere will produce significant variable amplitude and phase shifts when the signal returns to earth.) Also, weak signals are more difficult to get a clean result on. Contrast this with strong, groundwave signals, which are relatively easy to locate. I was able to locate BBC - Droitwich (198 KHz) and RTL (234 KHz) to within ~10 km using only 3 receivers and I was able to repeat both using a second completely different group of receivers as a check. I did the same with WWV on 2500 KHz (only one set of three receivers though). However, 5, 10 and 15 MHz are not trivial and derived location was highly variable. I assume that this is due to the significant skywave propagation there.

All this means that HF pirates probably have little to worry about by the Kiwi TDoA network. You are quite unlikely to be successfully located down to your house. (I can't comment on what the authorities might be able to do though, so beware.) A MW or LW pirate might want to pay attention though.

929
Other / Re: 6970 PSK UTE 1850 UTC 13 Jul 2018
« on: July 14, 2018, 0451 UTC »
FYI - Rochester, New York is the location of Harris RF Communications, where a lot of HF military equipment is made.

On a different topic, I have found it better when trying to do TDoA to not employ an RX that is very close to the TX being sought. As much as it would seem desirable, it sometimes appears to skew the result a little, as far as I can tell.

930
Other / Re: Link 11 6942 1145 UTC 13 Jul 2018
« on: July 14, 2018, 0441 UTC »
Hmmm. Must be a shipborne TX.





BTW, the slightly different location between the two images taken a few minutes apart with different receivers employed is not at all surprising, even if the TX wasn't on a ship. The point behind posting two photos is that the relative locations indicated on both are far from the image that Chris made yesterday.

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