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Messages - Charlie_Dont_Surf

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91
The RF Workbench / Re: Hereís a good one!
« on: October 05, 2023, 0128 UTC »
This is what mine looks like.



I think that from a mechanical strain standpoint, mounting the BNC connector there is suboptimal. If I was the designer, I would have put it on the bottom of the head unit so that the coax can just hang down. In any case, as a user, I would have used a right-angle BNC male-female on the connector to do more-or-less the same thing.

92
Guys - It is currently 30 September at 0039 UTC. Note the date of the original log here. This thread is from Thursday evening in North America.

93
North American Shortwave Pirate / Re: UNID 6910 USB 2349 UTC 27 SEP 2023
« on: September 27, 2023, 2357 UTC »
Assuming it's Filibuster again but not clear on that. Audio certainly sounds a lot better, for what it's worth.

2357 - Female automated voice: "End of Line. End of Line. End of Line." after song end. Nothing heard after that.

94
North American Shortwave Pirate / Re: Unid 6910 USB 2221 UTC 27 SEP 2023
« on: September 27, 2023, 2248 UTC »
audio a little off

Agreed. Very shrill and restricted, potentially speaker-to-microphone. Also sounds overdriven (too much gain). Unlistenable for me. I'm out.

Back on at 2348. Audio sounds better, except for the hip-hop.  ;D

95
Posting before Danger Kitty!

0002 - Open carrier starts.
0006 - Clock chimes at 0006. Heard what may be an ID but sound is quite muffled.
0007 - ID: "Midnight Radio", appropriately starting at near midnight UTC. "Midnight Radio would like to say hello to all the listeners". Planned discussion of sexual harassment.
0010 - The carrier itself is S9+10 on the K3FEF SDR. Introducing the announcers: Flan? Slam (corrected after they spelled it phonetically) and Draw?
0012 - Blue Ridge Summit address. Clearly a "vintage" recording.
0018 - Discussion of how to perform and get away with sexual harassment on a co-worker, referencing Justice Clarence Thomas.
0020 - ID. Fake advert for diarrhea med.
0023 - Discussion of labour unions.
0025 - I have played with the SDR bandwidth and my computer's graphic equalizer and the audio is almost tolerable.
0028 - A fake PSA whose content makes me think that it's good that the audio is quite muffled and difficult to understand.
0034 - Relay via NAPRS. "Good night and good DX" in a distinct New England accent. Carrier off.

96
Software / Re: Any SDR# (SDRSharp) Users Out There?
« on: September 17, 2023, 0656 UTC »
Interesting, that is one setting I change every time I unzip a new version of SDR# and I never have to go back to it ... until the next version is released. 

Which is annoying in itself. If it can't avoid wiping this out during an upgrade, that's pretty bad, IMO.

Just for grins, where do you have the sdrsharp-x86 directory located?

I don't have a sdrsharp-x86 directory. I have mine in C:\SDRSharp


97
0309 - Off, with computer voices talking about "polishing antennas", or lack thereof.  :)

98
I know that RVZ was often on and nobody logged him. Even I occasionally checked, heard him, and didnít bother to post. Only counting the number of logs would leave out a lot, which would also potentially skew the results.

Hmmm. What you wrote above and your actions contradict your stated conditions right at the top of the thread, which I have quoted below.

Quote
This is a list I have compiled based on loggings here on the HFU.

Clearly it's not entirely based upon only HFU logs. All I'm asking for is "do what you say and say what you do." Right now you are not doing that.

Mentioning "skewing the results" would imply that you are making an effort to be accurate.  Throwing in your estimates based upon non-objective guesses and swags is the height of "skewing the results".


99
I have contact with the op, I just checked an I got this:

First broadcast in August was AUG 3, on air until he was off the day of 14-15 AUG, off since 2 SEP. So actually 27, still more than any other station.

One observation I have is that for all other stations, you have counted actual reported logs of the station. However, for Hikair FM, your tally is assumed and not based upon actual loggings. You never directly answered my question about whether you actually logged them 31 days in August but I suppose that I have your answer. Whether it's 27 days or 31 days, it matters little; my question is about how the tally was collected.

At the risk of being an old fart, I've been having this on and off conversation with a friend about loggings and how the standard of detail and authenticity for what counts as an actual logging has apparently reduced over the years. This is along the similar lines. You are relying upon the op's word and not actual observation in this case. That would be completely verbotten years ago. I'm pretty sure that Glenn Hauser would take issue with that, for example.

It's your tally and you can do as you wish but perhaps just indicate that some of the data is "presumed" or "assumed" where appropriate. I, for one, would have nothing to complain about then.

100
North American Shortwave Pirate / Foxy AM 6925 AM 0132 UTC 16 Sep 2023
« on: September 16, 2023, 0133 UTC »
SINPO 45344 with some fading on the HFU mothership in Maryland with 900 foot skyloop.

0132 - 1970s "Urban contemporary". Occasional voiceovers by the op, "Oh yeah".
0139 - ID and "adjusting modulation" in a computerized voice.
0140 - The same douchebag that was QRM'ing WAVE is now doing the same here.
0149 - Announced music from the Bulgarian Symphony Orchestra. "Stand by for more ridiculous stuff."

101
SINPO 45555, S9+10 on the HFU mothership kiwi in Maryland with 900 foot skyloop.

0000 - EDM
0004 - YL, "W-A-V-E Radio. Ride the wave."
0047 - YL, "We are very existential. Ride the wave."   (Hmmmm...interesting way of using that word. Not sure what they are trying to say.)
0108 - Breifly off then back on with Kraftwerk, "Europe Endless"
0126 -  YL, "We are very existential. Ride the wave."  (There's that word again. Are they saying that they indeed do exist? I guess Jean Paul Sarte would approve.)
0127 - Strong dead carrier on 6948.75 killing the LSB.  :(
0128 - Carrier is gone.
0130 - Carrier is now sending CW ("CQ CQ, "), with some VFO swishing and QRM'ing.

102
SINPO 45555, S8 on the HFU mothership kiwi in Maryland with the 900 foot skyloop.

2344 - ID, "Filibuster Radio" by YL.
2345 - YL "Filibuster, filibustering." x3
0007 - "A Cuppa, A Cuppa, A Cuppa, Cup"
0008 - Eddie Cochran, "Summertime Blues"

103

Most Active Station: Hikair FM (24/7)

...

Hikair FM 31

I'm going to dispute the idea that he was on 24/7 in August. I'm not keeping records of things that I did not hear, but keep in mind that his TX is (purportedly) a lot closer to me than many of you knuckleheads. There were a few times  in the month of August when I made an effort to check and there was nothing there. Once or twice I even went to the trouble of checking on an SDR (KPH, KPS, etc.) with the same result.

Did you actually log him all 31 days last month?

Related: as far as I can tell, he has not been on 6200 since at least 3 September, perhaps earlier.

104
SDR - Software Defined Radio / Re: A theory on Kiwi TDoA ambiguity
« on: September 11, 2023, 2331 UTC »
Often looking at the raw results ("TDOA combined" map setting) is more helpful to figure out where the transmitter actually is, vs the "TDOA map" (just show me your answer) default option, especially when fine tuning things.

Agreed. Especially when you can not seem to get to a result on the "show me the answer" map after multiple tries, I often look into the raw "receiver x vs. receiver y" results and see which one(s) are most problematic. Eliminate/refine receiver choices and then try again.


I still maintain pirate ops do not have much to fear from TDoA. Many of them manage to out themselves perfectly fine without any direction finding assistance  ;)

Obtaining a truly "robust solution" (as they say in the statistics world, i.e., a believable result that you can be confident in) on a low-powered station can be very, very difficult in my experience. In my opinion, for a low-powered pirate transmitter, kiwi TDoA is more something to generate innuendo, suspicion and false results than to generate an answer you can believe in.

By the way, the people you really have to worry about are the FCC in the US or the equivalent in other countries (example: Ofcom in the UK). They have much better equipment than just kiwi TDoA and the FCC aren't using theirs to chase HF pirates very much these days. They are too busy chasing FM pirates in big cities.

Side note: Here's some of the unclassified capability that the US Military has. You can bet that the FCC has stuff that is on par or one step above this: https://youtu.be/MncDlhdBOlY?t=1772

105
SDR - Software Defined Radio / Re: A theory on Kiwi TDoA ambiguity
« on: September 11, 2023, 2323 UTC »
I agree that in the overall scheme of all the errors that are there and can be introduced, the length of the coax and the differences in antenna types is not going to be highest on the pareto chart.

TDoA is ultimately a process that relies on probability and statistics and the map result is always expressed as a probability. If you do one TDoA run, not knowing where the transmitter is ahead of time, and at the end of that run think that you have the one "true result", then I have a bridge to sell you. Statistics is a science of estimation based upon a pool of data and determining the confidence level in that estimate; one run is not a pool, for the purposes here, it's one sample. (Admittedly 30 seconds of sampling has many samples within it but with the time scale of HF propagation, for the purposes here, I call one TDoA result = one sample.)

Some of the things that I like to do are:

a) repeated runs using the same receivers
b) repeated runs using completely different receivers, if possible, or at least swapping in one or more receivers.

If I get more or less similar results each time, then I am more confident of the answer. (This is one of the basic rules of statistical inference.) However, more often than not, especially on lower-power transmitters, a) and/or b) lead to somewhat different results than previous runs. This means your confidence level in the previous result has dropped. Some of the reasons for this are covered in the links that SIGINT provided. There can be a "pulling" action depending receiver choice, for example.

Other things that have an impact are different propagation modes, daylight/nighttime over some of the receivers, and SNR.

What I do to maximize chances of success*:

1) a) and b) above
2) I always use IQ mode.  I am not sure if the kiwi TDoA algorithm performs separate I and Q correlations but I was told many years ago that IQ mode was essentially mandatory. I think that the TDOA algorithm can still generate phase information from AM, CW, SSB detection but I'm going to suggest that IQ mode is probably better for this to give it the most available information to work with.
3) Be wary of some receivers in daylight and some in nighttime. Seek to have all the TDoA receivers you use either all in the day or all in the night.
4) I try to use 3 receivers most of the time and only emply 4, 5 or 6 to solidify a result that I already determined using 3 to increase confidence.
5) The receivers in use can not be too close to the transmitter for HF TDoA, otherwise there will be strong errors. What's "too close"? It depends, but a minimum of ~300 miles/~500 km is a good rule of thumb.
6) Because of 5) above, I always start out wide and then decrease my focus area encircled by the receivers.
7) In general, I like equidistances between all the receivers and the target. This is why it helps to know where the transmitter is already. (Yes, I realize the irony here and so should you.)
8 ) Always favor receivers with better SNR on the signal you want to TDoA over worse. (Note that has nothing to do with a receiver's general SNR score.) To check out a receiver before you choose it for TDoA, double click on the receiver in the TDoA receiver selection map to open up a browser tab for that receiver on the frequency of choice. Make a choice of receiver(s) based upon reception quality. Don't just assume it will be OK without checking. (Garbage in --> garbage out.)
9) I generally use 15-second sample periods for initial screening and then move to 30 or 60 seconds to solidify confidence, or if things appear to be noisy.

*success to me looks like a result one high probability result in a diameter of maybe 50 km. This occurs very infrequently on non-SWBC transimitters!

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