Messages

196

Spy Numbers / Re: XingXing guangbo diantai 1 (V13)

« on: July 30, 2020, 1806 UTC »

Note the abrupt change at 1:03 from 18040kHz to 15890kHz. I've seen this happen several times when they don't broadcast at 00:00utc, the expected 15890kHz program appears on 18040kHz for a few minutes and the switches to 15890kHz.

I have seen them do this on every frequency set they use at one time or another.  It appears they sometimes forget to shift off the last time slot frequency, or they come up in the wrong frequency for the time, and then shift to the right one, mid transmission.

It appears the 1200-1330 slots on 9276 and 7502 have not been active  for a while now, almost 2 weeks since they were last used (I think the 18th of July was the last day those were active, but don't have a log in front of me so that is from memory).  The higher freqs in these time slots, 13974 and 15890 kHz, are still active.  I have been looking for other lower frequencies, to see if they have shifted to a new combination of freqs, but so far no joy.

T!

197

Spy Numbers / Re: XingXing guangbo diantai 1 (V13)

« on: July 27, 2020, 1254 UTC »

Just an FYI, it appears there might have been a schedule change.  This station has not been seen on 9276 kHz or 7502 kHz in the 1200 - 1400 time period since 18 July, 2020.  However, it is still active on those frequencies in other time slots, so the facilities do not appear to be inop.

13974 kHz and 15890 kHz still appear to be in use during this time period.

I have been looking for other frequencies below 13000 during that time period that might have taken their place, so far no joy.

T!

198

General Radio Discussion / Re: First Navy Command and Control Aircraft?

« on: July 20, 2020, 1953 UTC »

Pinto,

No, I was active duty in the late 70's and 80's.  However, before I went in the service I did some work in radar development, some of the folks at that company (and the civil servants they interfaced with) were retired mil going back to WW II.  Later, in the 80's, I went to work for a facility that had a lot of interesting radars and countermeasures gear on hand.  And again, some of the people at that facility had worked in the field since the late 40's, none of them had WW II specific experience, but immediately post WW II and Korean War was not uncommon.  Some of the external SME's we brought in were directly involved in radar development during WW II.  70+ year old guys with 45-50 years experience, having started at the infancy of radar, and lots of interesting stories.

Like I said, unfortunately I did not realize at the time how much history I was hearing and being exposed to, and how little of it is formally documented.

T!

199

General Radio Discussion / Re: First Navy Command and Control Aircraft?

« on: July 19, 2020, 2152 UTC »

Token, the summary states...ASV Mk.II  Developed at the Royal Aircraft Establishment at Farnborough in early 1940, ASV Mk.II differed from Mk.I mainly because it was properly engineered, and therefore much more reliable. Although called a 1.5m radar, it actually used 1.7m (176MHz). Range was up to 36 miles.

Yeah, the early ASV radars (like the Mk I) were a bit higher in frequency, above 200 MHz.  The ASV Mk II was 176 MHz.  The ASV Mk III was a mixture of freqs, starting with prototypes using the 176 MHz transmitter of the Mk II, but production versions ending up at much higher frequencies, up to 3 GHz.  I mean the first 3 GHz Mk IIIs were made by replacing the VHF transmitter of a prototype Mk III.  The Mk III had a very fractured history and documentation on it can be contradictory.

The excerpt of "When Computers Went to Sea" that I quoted makes it sound like maybe, just guessing here, the early PBY-5As were intended to have the ASV Mk I (probably the American made version, SCR-521 or ASE), and the antennas were built for that, and then ASV Mk II was installed and it was not originally realized there was a frequency mis-match.

I am fortunate enough that when I entered the field (in the 1970's) a lot of the "old hands" had first hand WW II radar experience or had been trained by those people.  I actually have a lot of hands on time with WW II radars, land based, sea based, and airborne.  Unfortunately, when I had the access I did not understand the history, and it was not until later when I started putting what I had been exposed to with what I could find in print.  SCR-584, SCR-720, APG-2, APS-6, and ASV Mk III are a few of the WW II era radars that I have had exposure to at one time or another.  But of those only the SCR-584 was in its WW II configuration, the others I was exposed to were all modified / adapted in some way to another application.  For example, the APS-6 and the SCR-720 were both used mounted on trucks when I saw them.

(edit)  Looking at the MIT Radlab series of books Volume 1 discusses the American made version of the ASV Mk II.  For the Army it carried the designation SCR-521, and for the Navy it was called the ASE radar.  This book also confirms that the ASV Mk II / SCR-521 / ASE were 176 MHz, it also states that the earlier ASV (I assume Mk I as it says no Mk number) was "near 200 Mc/sec".

T!

200

General Radio Discussion / Re: First Navy Command and Control Aircraft?

« on: July 19, 2020, 0437 UTC »

Interesting.  If that is a Sterba for a radar that would explain why their numbers diminished as the war went on.  As higher frequency, shorter wavelength, radars developed they would shift away from using such antennas.

That would also explain why I see so many pictures of those antenna equipped PBYs in VP squadrons, the long range patrol squadrons tasked with finding things like submarines.

Early war I can find pictures of at least 20 or 30 different BuNos with antennas like this.  I suspect there were a lot more, since the available public image catalog is far from exhaustive.

Looking at the images the wire segments look to be less than 4 feet long.  That would fit for a VHF radar, as several of the early airborne radars were.  The ASB, the ASV, ASV Mk II, etc.  Most every antenna I have seen associated (in documentation) with those radars were fixed dipoles or yagis.  But there is a specific entry in "When Computers Went to Sea" that discusses the problems with the early Sterba antenna and the ASV radar, specifically, the antenna and the radar were each not designed to work in the same frequency range.  The radar was at 176 MHz (this would indicate an ASV Mk II radar was installed) and the antenna was at 246 MHz (maybe designed for an ASB or very early ASV radar).  The fix of these antennas took place in early 1942, one source indicates January, 1942.  Initially 12 aircraft were fixed, then the fix pushed out to others in the fleet.

T!

201

General Radio Discussion / Re: First Navy Command and Control Aircraft?

« on: July 18, 2020, 2205 UTC »

OK, further research.

This aircraft is BuNo 8191, a PBY5A.  I have not been able to find out where the picture is, I initially thought maybe Pearl, but North Island or one of the Pacific islands seems more likely.  I have not been able to figure out which unit(s) the aircraft was attached to.

This is one of the Sea Cats, not the Black Cats, although their antenna configurations are essentially the same.  The Black Cats would probably (most of them, but not all) have different antennas forward.

This antenna configuration was common for aircraft that were used in a long range patrol application.

Basic, early war, PBY-5A configuration for long range patrol.  The antenna configuration was used until the end of WW II (and after), but became less common as the war went on.  The color combination was used by several different units.

T!

202

General Radio Discussion / Re: First Navy Command and Control Aircraft?

« on: July 18, 2020, 1630 UTC »

In the forum these were originally posted in, are there any images showing the engines?  And if so, could you see added flame dampers on the exhaust?

Over the years I have seen a few images of Catalinas with extensive antennas like that.  I am not sure that was a specific configuration for something like C&C.

Off the top of my head this looks kind of like one of the VP-11 Black Cats, although I thought those were a bit darker.  They had a couple of PBY5 Black Cat Commands.  Alternately, VP-54 and VP-72 had some Black Cat Ferret ELINT aircraft, the Cast Mike #1 team and others.

Shoot me a PM with the name of the other forum, I am always up for an aviation related forum I might not already be a member of.  Or if I am a member a thread I missed.

In the mean time, I will check some books in my library here.

(edit)  On second thought, this looks like a fairly standard and typical color scheme and antenna configuration for several Patrol aircraft of both VP-14 and VP-44 in early WW II, there is an image of a VP-14 aircraft (BuNo 2418, VP-14 Patrol 2) at the Pearl Harbor amphib ramp in early December, 1941 that could easily be this aircraft.  Not the same image at all mind you, but the colors, antennas, and ramp look about right.

T!

203

Spy Numbers / Re: XingXing guangbo diantai 1 (V13)

« on: July 15, 2020, 0058 UTC »

For the most part numbers stations are a passing interest for me.  I mean, if I am setting at the radio I may try to catch one that I know will be on the air, but I don't really pursue them.  The exceptions are V24 and V07, both of those I record / look for attempting to catch every transmission.  The same with V30, when it was active.

I tend not to use remotes for the stations I focus on.  Nothing against remotes, and I use them to catch what can't be caught directly here, but when I am looking hard at a station it tends to be a station I can receive first hand.  And that is why I looked hard at the 1200-1330z V13, because that is the time period I catch here first hand.  I guess I should look for the 0000 - 0400 time slots, just to see how well they are heard here.

The lack of consistency on V13 is very odd to me, and pretty much the only reason I focused on it recently.  It just does not make a lot of sense.  Of course, the V30 activity, sending the same message on apparently random days for months on end, was probably why I paid attention to that one.

T!

204

Utility / Re: 11175 callsigns

« on: July 13, 2020, 1257 UTC »

Keep in mind there are also daily rotating callsigns, and no one will have a list of those.  These are randomly selected callsigns that change at 0000 UTC every day.  When you hear an EAM (coded numbers and letters) or similar message on 11175 kHz (or any HF-GCS frequency) the callsign used will most often be either a group callsign (such as MAINSAIL) or one of these daily changing callsigns.

T!

205

Spy Numbers / Re: XingXing guangbo diantai 1 (V13)

« on: July 13, 2020, 1243 UTC »

I've been spending alot of time lately on various Japanese remotes trying to copy JJY (I've always wanted to copy the English language news fax and have never been able to even come close from my QTH in Missouri)  while waiting I've stumbled across V13 a few times
I'm my local mornings:
July 9. 9276 KHz 12:01-12:26 under strong FEBC on 9275. Also on at:

12:30 - 12:55, actually starts a minute late and goes a minute long 12:31 - 12:56

13:00 - 13:26. I missed the start but the sign off was at 13:26 so sign on was likely 13:01

13:31 - 13:56

Over the last few months I have received and recorded essentially every V13 transmission on 9276 kHz and 7502 kHz in the 1200, 1230, 1300, and 1330z time slots.  I have done this trying to determine if there is a pattern to what days / times what frequencies or combinations of frequencies are used.

After 3 months of looking, I will have to say it appears there simply is not a pattern.

Most days 9276 kHz (and 15890 kHz) is used in the 1200z and 1230z time slot and 7502 kHz (and 13974 kHz) is used in the 1300z and 1330z time slot.  However, it is not always that way, and there seems to be no pattern to the variations from this.

I have seen days with no transmissions at all, although only a very few such days.  I have seen days with the "normal" 9276 kHz at 1200/1230z and 7502 kHz at 1300/1330z.  I have seen days inverted, so that 7502 kHz is during 1200/1230z and 9276 kHz is 1300/1330z.  I have seen days when 1200/1230z transmit and 1300/1330z does not.  I have seen several days when 1200z does not transmit, but all three other time slots, 1230, 1300, and 1330z, all do.  I have seen days when 9276 kHz was used in all four time slots, and other days when 7502 kHz was used in all four time slots.

I have seen one day when both 9276 kHz and 7502 kHz were used simultaneously and in all four time slots, 1200/1230/1300/1330z.  But with different traffic on each freq.

As for start times, they seem to vary a bit.  Two months ago the start times were slightly before 1200/1230/1300/1330z, say 20 or 30 seconds before the top and bottom of the hour.  Today 9276 kHz started at 1201:36z.  It is as if the clock they are using looses a couple seconds a day, and no one has resynced the clock in a while, so the start time has gotten later and later since the last time it was synced.

All on 9276 KHz H3E. With very strong FEBC all but obliterating the signal. During the occasional lulls in FEBC I could see some modulation on LSB. Not enough to be considered full AM but not fully suppressed either. Sometimes the carrier is dropped in the 5 minutes between broadcasts. This happened at 12:26 but didn't happen at 12:56. Carrier was dropped at 13:26 also. Not heard on usual parallel 7502 KHz.

The mixture of H3E and full DSB AM seems somewhat random.  9276 kHz is sometimes, possibly most often, H3E and sometimes full AM.  7502 kHz is normally full AM but sometimes is H3E.

The carrier on / off between messages seems to be frequency dependent.  Typically 9276 kHz will turn off the carrier between messages, but 7502 kHz seldom does.  If I had to guess, and it is clearly just a guess, it may be that different people/techs may be running each transmitter, and one person turns it off between messages, the other person does not.  There are other minor activities that may support this, such as transmitter tuning for each frequency.  It just feels like they (the two transmitters) are not run by the same person.

You said "Not heard on usual parallel 7502 KHz".  7502 kHz is not in parallel with 9276 kHz.  In the past 2+ months I have seen them both active at the same time only one time, and that time they had different traffic on the two frequencies.  Typically there are at least two frequencies active at any one time, but it is not 9276 / 7502 kHz.  Most often when 9276 kHz is active you will also find the station on 15890 kHz.  And when 7502 kHz is active you will also find 13974 kHz active.  However, these second outlets are not carrying the same program, 9276 / 15890 kHz may be active at the same time, but different traffic on each, the same with the 7502 / 13974 kHz pair, active at the same time but different traffic.

T!

206

HF Mystery Signals / Re: Beacon network/Sonde logging 6/17/20 1644 to 1730 UT

« on: July 03, 2020, 1531 UTC »

How often are you seeing these signals?  These are not the same (at least, I think they are not) as the Pips network, however I think I have seen the same signals you are talking about, the modulation you mention is familiar, but on different freqs.

T!

207

HF Mystery Signals / Re: Rtty looking signal 4280kHz at UTC: 1420 Europe

« on: June 26, 2020, 0104 UTC »

This is PBB, a Dutch navy station.

850 Hz shift, 75 Bd, FSK.  And it is not encrypted, you should be able to turn it to clear text.  I don't remember off the top of my head, but try 850 Hz shift, 75 Bd, 5N1

The results might look odd to you, but should be the same line repeating every transmission cycle, something like:
02A  04B  06A  08B  12A  PBB

T!

208

HF Mystery Signals / Re: 9977 kHz at ~6kHz wide Data?

« on: June 19, 2020, 1517 UTC »

Honestly, to me that does not look like data to me, it looks like a carrier modulated with a 325 Hz tone.  Alternately, it could be FMCW of some kind, sinusoidal, sawtooth, etc, with a 325 Hz modulation rep rate.

T!

209

General Radio Discussion / Re: Electronic surveillance of protesters

« on: June 13, 2020, 1305 UTC »

During the local "big" (coordinated effort resulting in about ~1000 marchers) gathering here a week ago there was reportedly an MQ-9 Reaper overhead the entire time.  If true it may, or may not, have been related to the protest, they are often overhead here anyway.

T!

210

Equipment / Re: What are you using for SWLing?

« on: June 02, 2020, 1615 UTC »

I have a Realistic DX-300 which is nice at times, but impossible to use if for SSB - it drifts like an unmanned boat on a swift river.

I almost got a DX-300, but missed out on the auction. Then I was going after a DX-160, and then DX-150, and outbid again.
But I managed to get a DX-392, and then Sangean ATS-803A in good price.  These are great receivers I find. They are very sensitive, stable and sounding good.

I am shocked to hear nice looking DX-300 is such a bad performer drifting too much to hear SSB.  Should I be glad that I missed them out, or is your DX-300 a lemon?

I find the DX-300 acceptably stable on SSB if you let it warm up for a while before hand.  For sure for the first 30-40 minutes it is all over the place, but it does stable out a bit after a while.  It kind of depends on what your reference is, compared to radios I started with the DX-300 is OK, accpetable, but not great.

In my collection I have most of the DX series desk top radios, DX-75, DX-100, DX-150, DX-150A, DX-150B, DX-160, DX-200, DX-300, and DX-302.  The only two DX desktops I don't have that I can think of off the top of my head are the DX-120 (never have had one of those) and the DX-394 (have had one before).  For sure the two best are the DX-160 and DX-302 (I never liked the 394, but that is probably just opinion based, I never liked the look), but really, except for the DX-100, they are all pretty similar in basic performance, even when very different in features and appearance.

What do I use for SWL today?  I am more of a Utility guy, but I do SWL a bit, most often one of my local SDRs when searching, but if I am just letting a radio set on a station it might be one of the boatanchors, the Hallicrafters SX-42, SX-71, and 62A are all favorites, but the National NC-183D is also something I like to hear.  I rotate which baotanchors are beside the listening desk, so really it depends on what is in the living room at the time.  The other day I had a Hallicrafters SX-16 out that I was listening to VoK on.

T!