Messages

766

Spy Numbers / Re: V24 South Korean Numbers Station 6215 kHz appeared again

« on: December 10, 2016, 1341 UTC »

Yes, V24 appears to have abandon 5290 kHz at 1430 UTC on day 3, 5, 13, and 15, and have reactivated 6215 kHz at 1500 UTC on day 5 and 7, and we will probably see it on days 15 and 17 also.

T!

767

North American Shortwave Pirate / Formerly known as YHWH 7405 AM 0313 UTC 10 December 2016

« on: December 10, 2016, 0317 UTC »

Former YHWH up 7405 kHz AM, started at 0313 UTC, Dec 10, 2016.

(edit)  Either off mid sentence, or a very deep, sudden, and long fade at 0335z.

T!

768

General Radio Discussion / Re: Reproduction of Amelia Earharts transmissions, Dec 14 and Dec 15, 2016.

« on: December 08, 2016, 2247 UTC »

Update to this here:
http://forums.radioreference.com/amateur-radio-general-discussion/344111-amelia-earharts-transmission-pacific-update.html

It looks like they have slid it one day, now going to TX on Dec 15 and 16, at 1230 EST and 1300 EST (1730 and 1800 UTC).

Still not much of a chance of being heard in the US, but I will record the freqs anyway, just in case.

T!

769

North American Shortwave Pirate / Re: YHWH 7410am 0305 UTC 12/3/2016

« on: December 04, 2016, 0520 UTC »

7410-AM, religious pirate (formerly known as "Radio Station YHWH").
The last two times I recently heard "Joshua," his signal was very good,
with about 100% readable, but today (Dec 3) the reception was
surprisingly very poor.

0338 UTC was less than semi-readable; 0420 was completely unusable
(but open carrier) and the same at 0501.

Am very surprised that others, out of state, were hearing this station
at all, as I didn't think tonight's signal would get very far beyond California. 

I have not logged it yet, but I understand that the "Radio Station YHWH" IDs have not been heard within the programs?

I wonder if these are originating from the "real" Joshua, or from someone else, who is relaying recordings? It would seem kind of foolhardy for the actual YHWH guy to start broadcasting again, since the Feds caught him red-handed last time, and know who he is, and where he is.

Of course, he may have relocated his transmitter and it wouldn't be the first time that an HF pirate has returned to the air weeks or months after an initial FCC bust and "stern warning".

But, can't rule out the possibility that these may be relays of previous YHWH broadcasts by a different person.

In the past, I often monitored "Joshua," as he IDed himself on
air in the past. My recent Nov 25 reception (posted here)
consisted mostly of recordings that I had often heard before
when he was broadcasting some years ago, BUT there was
a segment that I was very confident was NEW, as it seemed
to be new material from him. Even his voice sounded slightly
different, but certainly was him. My audio of a portion of that
new segment is posted at  http://goo.gl/fN8Ie3  .

That segment is one he had included in the past, I have heard it before.

Over the ~1.5 years he was active his program changed from time to time, as he added segments or removed them.  In the end he had 2 one+ hour CDs that he used as his program.

I caught his transmission on Dec 3, the same one you reported in this thread.  Every section he played I had heard before.

T!

770

North American Shortwave Pirate / Re: YHWH 7410am 0324 UTC 12/4/2016

« on: December 04, 2016, 0503 UTC »

When he first started regular transmissions in Jan - Feb of 2014 (he was active before that time, but less often, I first heard him in May of 2013) he was doing the same thing, mostly inside BC bands, typically either 41 meters or 49 meters, and several nights a week.  By March of 2014 he was being more adventurous, operating outside BC bands and even inside ham bands.  There in the end he was doing several transmissions every day, at announced times and on regular frequencies.  He did about 8 months of these regular operations, sometimes 4 transmissions a day, before he was busted in Dec of 2014.

T!

771

SDR - Software Defined Radio / Re: Software Phasing with your SDR

« on: December 04, 2016, 0141 UTC »

Isn't this exactly what the FCC does?  Active short verticals arranged in a circle they can electronically steer to DF?

I have never seen their equipment, and I suppose it is possible they do steer using phase, but I think it more likely they use a Doppler based RDF.  The base leg on a vehicle is probably too short for much use in phase based DF.

Interestingly, from this video ( https://www.youtube.com/watch?v=QIGAOLJh-XE&t=16s ) it appears that in their mobile units when they tune to a signal they get automatic direction, not surprising, but also a database comes up and tells them every thing licensed on that bearing.

T!

772

North American Shortwave Pirate / Re: Wolverine Radio, 6940 USB, 0007 UTC, 12/04/16

« on: December 04, 2016, 0114 UTC »

Great show as usual, not a strong signal, conditions were not great and neighbors grow lights hurt it a bit, but still decent.  Thanks Wolverine!



T!

773

SDR - Software Defined Radio / Re: Software Phasing with your SDR

« on: December 02, 2016, 0357 UTC »

Can two antenna be used for DF? I agree with Token, probably. Going to figure that out. And from what I've read about phasing, its best to have two antennas that are the same, ideally omni. I currently have an omni and a N-S loop. Some directions phasing works great, other directions, not at all (because the loop doesn't do well in picking up station E-W of here so there little to no signal to cancel out the signal from the other one). And I put absolute zero thought in coax length from the antenna to the radio, figuring that's what the phaser & its knobs were for. But that too shall be seen. Two crossed loops perhaps, plus the omni? A couple of loops or other directionals? Been wanting to try a pair of D-KAZ's and phase them for steering, but now with this SDR, can we do that mathematically instead of physically/electrically? And what actually are ideal antennas for phasing, DF, other?

My plan is to try 2 Wellbrook 1530+'s, mounted on rotors.  I currently have one, and have ordered another.  This should make two relatively wide banded antennas that are close in gain and radiation pattern.  And each can be turned independent of the other.

It seems to me when you null using the technique in Chris's video you are steering the "beam" formed by your two antennas, so that one of the two nulls is towards the direction you want to reduce.  I wonder what happens when you combine the electrically steered null with a mechanically steered null?  Using one loop and one other antenna would result in a mismatch in gain when you change the loop direction and get its nulling in the picture, would probably ruin the electronic steering unless you reset gains.  But using two loops... 

I think the process might go something like this.  With one antenna, mechanically turn the antenna and note the nulled direction to the station in question.  Now mechanically turn both antennas 90 degrees from that point, this should make the station maximized on each antenna / SDR channel.  Now null as shown in Chris's video.  Then turn both antennas to the mechanical nulled bearing first noted.  I am thinking that because the relative signal strength, or gain of each channel, is still in the ratio originally set in electronic steering you should get the combined nulling of the mechanical position and the electrical steering.

Maybe.

T!

774

SDR - Software Defined Radio / Re: Software Phasing with your SDR

« on: December 01, 2016, 1818 UTC »

Further thought.

Assuming feedlines are matched, as I did in my previous post,  simplifies things, you just have to know the physical separation of the antennas to calculate maximum possible phase delta for any specific frequency.  But what about if the feedlines are not phase matched?

I would think it would be not too difficult in software (again, says the hardware oriented guy) to calibrate the system to “as installed” values.

You have two antennas, A and B.  Two points make a line.  Extend the line off either end and place a signal generator out along that line some distance away, the actual distance does not matter, but I would think you would want it at least as far as the distance between the two antennas, and probably beyond that.  The signal generator is set to CW, and by that I mean real continuous wave, not Morse code, I mean an unmodulated carrier on the frequency of interest.

In software you can tell the phase difference of the received signal between the two sources (antenna A and antenna B), including phase shift for the physical separation and feedline lengths.  If you know the physical separation you can back that value out and you now know the phase difference of the feedlines.  You also now have all the information required to get an angle of arrival for DF purposes.  You could also do this with the source located exactly in the middle between the two antennas, but the math behind the process would be slightly different.

Whichever way you did it you could also use this signal to calibrate the gain values for each antenna, the "in the middle" process might have better results for this aspect.

You could calibrate multiple frequencies across the bands and end up with a lookup table for any frequency you tune to.

Not everyone has a signal generator they can use.  However it would be a relatively easy project to use an AD9850 or 9851 DSS with an Arduino for control to build a simple programmable sig gen .  Total cost in parts would probably be less than $20, and the 9851 is good to 125 MHz, while the 9850 is only 30 MHz.

T!

775

SDR - Software Defined Radio / Re: Software Phasing with your SDR

« on: November 30, 2016, 1901 UTC »

I wonder if this could be used to df?

Probably.  However, it might not be straight forward.  Off the cuff here, and just throwing out things as they pop in my head.  Also keep in mind I have not tried this software yet, so some of this is guess work on how it might all function.

The best situation would be two small horizontal footprint identical antennas.  Call it two multiband verticals, or maybe two mag loops.  For argument and ease of example lets say this is two antennas spaced 50 meters apart and on a North / South line with antenna A (channel A in the software) at the North end and antenna B (channel B in the software) at the south end

The beam from an array of two such antennas is going to be pretty broad, with a not very well defined peak.  However the null should be much more sharply defined.  This means to me that DFing using the null instead of the peak would yield better results, assuming you have enough signal strength to do this.

If the feedlines are matched phased lengths (regardless of physical length, but with matched phase delay through the pair of feedlines) then a bearing perpendicular to the plane of the two antennas would yield 0 degrees of phase difference, with the antenna configuration I stated above and since this is only two antennas this would be bidirectional, meaning it could be either 090 or 270 degrees, with no way to be sure which.  But remember what I said about the null being sharper.

I think that means that if you put in 180 degrees of phase difference between the two channels of the SDR then you would generate a null that was perpendicular to the N/S line defined by the antennas, or now “point” the two  main nulls on 090 or 270 degrees bearing.

The perpendicular case is easy, because that is always a 0 degree phase difference signal on arrival. Anything off perpendicular is more complex.  If the two antennas are spaced exactly ½ wavelength apart  then the parallel, or end fire situation, is also pretty easy to define.  A signal arriving from a bearing in line with the two antennas will be 180 degrees delta between the two channels.  So 0 degrees of phase shift between the two SDR channels would place the null on the 000 / 180 line, and as shown above 180 degrees of phase shift would place the null along the 090 / 270 line.  So now, for this specific physical setup you can calculate any point around the circle.  For example with a phase shift in software of antenna A leading antenna B by 90 degrees in phase the nulls would be shifted to the 045 / 225 bearing lines.

But that easy math only applies if the two antennas are physically ½ wavelength apart and if the two feedlines are phase matched.  And of course wavelength and phase length depend on frequency.  So the electrical delay relationship between the two antennas and the relative phase length of the feedlines will change as you change frequency.

It should be relatively simple (a small matter of software, says the hardware oriented guy) to do automatic calculations based on known values.  For example assume that the feedlines are the same physical length and type of coax, in fact make that a requirement.  That removes that feedline variable from the equation.  Then if the spacing  of the antennas is known and the orientation of the antennas is known, the phase relationship for any given bearing on any frequency can be calculated.  That could be used to “steer” the null to any given bearing pair.

Now, the next step in thought.  Once you can control the null (or peak, if you want) to a known point what else can you do?  If you now cycle the phase relationship from zero to max +phase, back to zero, to max –phase, and back to zero, you have just “scanned” the beam (or null) in a full circle.  If you plot the amplitude of a given signal (and if there is only one signal on frequency) while scanning this circle you could plot what is basically the beam pattern of your two element array, and the peak of the pattern would point towards (and away) the signal source.  If you offset phases so that you are plotting the null then the null will point towards (and away) the signal source.

Next step in thought.  Once you can control the beam in this way and plot the results, electronically spin the array quickly and plot the results on a circular PPI like display.  Presto, you have a real time PPI or compass rose that can indicate direction of arrival.

Just some quick thoughts.

T!

776

HF Beacons / Re: Yosemite Sam Dasher

« on: November 29, 2016, 1629 UTC »

Rocky and Rainy are both operating, I can hear them right now.  Also the third beacon mixed in with them that no one has ever identified is heard.  I have not heard Hexi2k (6700.5 kHz) for some time, and I used to hear it quite well daily so I assume it is not operational.

(edit)  Never mind on Hexie2K, 45 minutes after I posted this Hexie2k came on or up out of the noise, and is now heard here.  However, the signal is not what I am used to for this beacon, could something have changed at the transmit site?

T!

777

Spy Numbers / Re: HM01 on 11462khz 0500UTC 26NOV

« on: November 28, 2016, 1843 UTC »

Mixing audio (RHC audio mixed with HM01/M08/V02, or numbers station audio during an RHC transmission), starting with the incorrect audio (as you described), and those kinds of things have always marked the Cuban spy numbers operation.  However it is not really a big deal, by NOT IDing they are not keeping their transmission locations a secret.

Such errors are, however, almost always amusing.

For anyone with the resources of a nation-state triangulating the transmission source of any HF signal is childs play if that is a goal of the nation-state.  Shoot, even at the hobby level it is pretty simple to do.  So hiding the transmission source location of any numbers / spy station is not important, who / where is sending the signal is only a secret to some hobbyist, not to any professional or non-professional but dedicated group of radio monitors.

The only things really “secret” about these transmissions are the message contents and exactly who is the intended recipient.  The source location cannot be secure.

T!

778

General Radio Discussion / Reproduction of Amelia Earharts transmissions, Dec 14 and Dec 15, 2016.

« on: November 27, 2016, 0315 UTC »

Someone posted a plan to transmit on Amelia Earhart's frequencies from one of the islands she may have crashed on.

Details, few though they are, here :  http://www.antiqueradios.com/forums/viewtopic.php?f=5&t=311243

It looks like this is not very well thought out.  The times of transmission will be at 1900 UTC (1400 EST and 1100 PST) on Dec 14 and Dec 15, 2016.  The frequencies used will be the 3105 and 6210 kHz that Amelia Earhart used.

Whoever planned this does not have a deep grasp of propagation.  Those frequencies, by that time of day, will have essentially shut down, as there will be a daylight path from the island to the US and those freqs are regional, at best, during the day.

T!

779

North American Shortwave Pirate / Re: Wolverine Radio 6950 USB 0007 UTC 11/27/16

« on: November 27, 2016, 0014 UTC »

As normal, excellent signal and audio into the Mojave Desert this evening.  Scotch in hand, Wolverine on the house sound system...seems like a promising Saturday evening.

T!


The SSTV as received here in California:

780

HF Beacons / Re: Stumpy changed rate maybe 7000.72 kHz 1429 UTC 6 November 2016

« on: November 26, 2016, 1701 UTC »

Checking this ditter for the first time in a week or so I see it has changed rates again.  Right now there is about 16.8 seconds between each dit.

T!