New V24 prediction chart, April 30, 2016

[Token]

Based on observations since V24 re-started transmissions on February 14 I have put together a prediction chart.  For the first couple of months V24 appeared to be trying new things and has only settled into relatively stable operation for the last 6 weeks or so.

V24 appears to have narrowed its times of operation from past operations, repeated transmissions appear to only happen with start times from 1430z to 1600z.  There have been some transmissions before 1430z, however those appear to have been before V24 started using a repeating schedule.

V24 has changed the cycle that it operates on.  In the past it operated two days in a row with the same message at the same time on the same frequency.  So on day 5 of the month at 1500z on 5715 kHz a transmission would occur, and the next day, the 6th day of the month, the same message would be sent at the same time on the same frequency.  However now it no longer does this.  Instead now it waits a day between transmissions.  So that on the 5th day of the month at 1500z on 6215 kHz a transmission occurs, it skips the 6th day, and on the 7th day of the month at 1500z on 6215 kHz the same transmission is sent again.

My newest prediction chart can be found at the same place it is always at:
http://www.tokenradio.net/Radio/SharedFiles/NumbersTfer/V24_M94_latest_sched.JPG


T!

[MDK2]

Thanks for this. I have been following the chart at chobi dot net (linked below) and had noticed that every single March transmission was also broadcast on the same time, date, and frequency in April, but April has also had three added transmissions that did not happen at the corresponding time in March.

http://radio.chobi.net/DX/data/V24KoreanNumbers.html

Token, I had a question for you. I've seen you speak of having antennas aimed at Asia (or sometimes not aimed that way) and was wondering what you use? I have an extremely hard time trying to receive V24 and haven't successfully heard it once. (V13 is pretty hard too, but at least I can find it down in the static on occasion.) I know I don't have a great antenna (improvements coming soon, but it won't be in the form of a large dipole or inverted V), but the path from East Asia to Colorado travels over a pretty sizable chunk of land which makes me wonder if I'm wasting my time trying. Thanks.

[Token]

Thanks for this. I have been following the chart at chobi dot net (linked below) and had noticed that every single March transmission was also broadcast on the same time, date, and frequency in April, but April has also had three added transmissions that did not happen at the corresponding time in March.

It is pretty typical of V24 to have slight month to month variations.  The schedule evolves over time, so that 3 or 4 months from now there will probably be noticeable differences from today.

http://radio.chobi.net/DX/data/V24KoreanNumbers.html

I periodically check that chart also, as well as a few other places.  I notice that this month the sources for that chart finally got one of the 1600z transmissions.  I wonder why they are not seeing those transmissions very often?  There were three transmissions inn the 1600z time period in April, and four in that time slot in March.

Token, I had a question for you. I've seen you speak of having antennas aimed at Asia (or sometimes not aimed that way) and was wondering what you use? I have an extremely hard time trying to receive V24 and haven't successfully heard it once. (V13 is pretty hard too, but at least I can find it down in the static on occasion.) I know I don't have a great antenna (improvements coming soon, but it won't be in the form of a large dipole or inverted V), but the path from East Asia to Colorado travels over a pretty sizable chunk of land which makes me wonder if I'm wasting my time trying. Thanks.

I have a few different HF antennas, including 3 pointed specifically at Asia and the South Pacific.  One Rhombic (450 feet apex to apex, pointed 310 deg true) pointed at Asia, one V-Beam (legs about 300 feet long) pointed at Asia, and another Rhombic pointed at the South Pacific.  Other HF antennas here include a third Rhombic pointed at Europe, multiple dipoles from 160 meters to 20 meters, a couple of small loops like the Wellbrook 1530, a Skywave Loop, and a few beams covering just below 40 meters and up.

With your location in the winter you are more likely to be able to hear V24 and the 1200z / 1300z schedules for V13.  I have operated mobile from CO (and other states) and heard both stations there, but for sure not as well as I hear them here.

What you can do for antennas depends on how much area you have to work with.  The V-Beam can be an option if you want to optimize in a specific direction, but while not as large as a Rhombic they are not small.

T!

[MDK2]

I periodically check that chart also, as well as a few other places.  I notice that this month the sources for that chart finally got one of the 1600z transmissions.  I wonder why they are not seeing those transmissions very often?  There were three transmissions inn the 1600z time period in April, and four in that time slot in March.

I had noticed that they weren't updating the chart as quickly as other times. (There are a few times when I was checking at, say, 1500, and the broadcast log being updated right at that moment, so it's disconcerting when a few days pass without any new data.)

I have a few different HF antennas, including 3 pointed specifically at Asia and the South Pacific.  One Rhombic (450 feet apex to apex, pointed 310 deg true) pointed at Asia, one V-Beam (legs about 300 feet long) pointed at Asia, and another Rhombic pointed at the South Pacific.  Other HF antennas here include a third Rhombic pointed at Europe, multiple dipoles from 160 meters to 20 meters, a couple of small loops like the Wellbrook 1530, a Skywave Loop, and a few beams covering just below 40 meters and up.

With your location in the winter you are more likely to be able to hear V24 and the 1200z / 1300z schedules for V13.  I have operated mobile from CO (and other states) and heard both stations there, but for sure not as well as I hear them here.

What you can do for antennas depends on how much area you have to work with.  The V-Beam can be an option if you want to optimize in a specific direction, but while not as large as a Rhombic they are not small.

Thanks for the information and tips. Space is a problem for me - although I have a pretty decent sized lot (for the city), my backyard is diagonally bisected by our house power line, which comes in nice and low, maybe 20 feet above the ground. It not only hampers where we could plant trees when we bought the house, but means I have a triangle shaped patch of space (much of it squeezed between my house and my next door neighbor's) to work with. But I will look into those styles you mention and see what I can do.

Thanks so much for the information!

[MDK2]

I listened in via a South Korean SDR shared on globaltuners.com to some of these transmissions. A couple of corrections to report:

On May 26th, V24 heard on 5715 at 1500, not 1430. (Per chobi.net log, this was the case on March 26 and April 26.)
On May 27th, V24 heard on 4900 at 1530. (Per chobi.net log, this was the case on March 27 and April 27.)

I forgot to check on May 28th, but the chobi.net log has them transmitting on 5715 at 1500 for March 28th and April 28th. They stopped logging back on May 7, but it seems likely they were on at 1500 this time around as well.

Thanks Token!

[JCMaxwell]

Token,

Your V24 chart is referenced in this month's Spectrum Monitor.

[Token]

I listened in via a South Korean SDR shared on globaltuners.com to some of these transmissions. A couple of corrections to report:

On May 26th, V24 heard on 5715 at 1500, not 1430. (Per chobi.net log, this was the case on March 26 and April 26.)
On May 27th, V24 heard on 4900 at 1530. (Per chobi.net log, this was the case on March 27 and April 27.)

I forgot to check on May 28th, but the chobi.net log has them transmitting on 5715 at 1500 for March 28th and April 28th. They stopped logging back on May 7, but it seems likely they were on at 1500 this time around as well.

Thanks Token!

Thanks for the reports.

As always, V24 is in constant change.  This station has done this as long as I have been watching it.  As soon as a prediction chart is put out the next month there are typically some small changes, and V24 always has a few transmissions that do not fit any pattern each month, that is why I never say these charts are more than about 80% or so accurate at the time of publication.  And I also typically say "at the time of publication", because as time goes on they get less and less accurate.  Typically I try to put out 2 to 4 charts a year to somewhat keep up with the changes.

Re May 26, 5715 kHz, at 1500z.  Yes, in March and April V24 transmitted this time slot, but previously they had used 1430z.  Note that the chart is called "1Q 2016", for first quarter, 2016 and I published it on April 26, before 1200z.  The end of March was the end of the first quarter.  It appears V24 was in the process of changing this time slot schedule across the end of the data collection for this chart.

I typically wait until I have at least two examples of a time / frequency slot before adding it to the chart, and at publication the second transmission confirming the change of operations had not happened yet.

This time slot (26 and 28 day of the month, 5715 kHz at 1500z) will appear in the next chart, assuming V24 is still using it when I put the chart up, as I have the March, April, and May transmissions recorded for 5715 kHz, 1500z.

Re May 27, 4900, at 1530.  I was out of the country and my recording system failed from May 26 to June 3 for this frequency, so I have no data for May 27, 4900 kHz.  However I do have the recordings for March and April.  The same problem again.  The change in schedule may have been happening at the time I put the chart out.  At that time only the single March transmission had happened, with no second transmission yet sent to back it up.

Further, my April 27 recording does NOT show 4900 kHz, 1530z active, although my March recording does.  Of course it could be a case of propagation killing the signal for me, however based on the presence of other Asian signals in the recording I do not think this is the case.  Looking at the chart on chobi.net (here http://radio.chobi.net/DX/data/V24KoreanNumbers.html ) I see several suspect entries.  I am less sure that is a day to day logging than someone building a chart from compiled previous information.  For example, they show the 5900 kHz / 1600z time slot as active on 15 April, but it was not used that month, and it was used the previous month (15 March, 5900 kHz, 1600z).  15, 18, 22, and 25 day, 5900 kHz, 1600z was used in March, but only 18, 22, and 25 day was used in April.  I reported the March operation to them in early April, and they appear to have inserted it in the April reports.

This time slot (27 day of the month, 4900 kHz at 1530z) will appear in the next chart if V24 is still using it at that time.  However, because of the 23 and 25 day of the month same freq / time usage there may be some flexing going on here.  I have often suspected that V24 uses several time slots as "catch up" slots, and the station appears less rigidly fixed in those slots.

T!

[MDK2]

Thank you for the detailed and thorough response. I agree that the chobi.net chart is at times suspect, but I know from experience that some of the entries were logged at the precise time of transmission (e.g., a 5790 transmission at 1500 on April 26 being entered at on April 26 at 1500 - I was trying to hear it and hitting refresh and seeing the page updated. Important to note that this isn't an exact example because I never wrote down the dates when I saw that happen, just using it as a possible example.) The point being that sometimes it was updated "live," at other times a week would pass before they updated it.

Anyway, V24 observer "Moomin" has a chart available for download. (He said that you told him that you've been following V24 since 1978, so we do respect your expertise on the subject of this station.) I will have to get the link from him again, as he provided it in a chat on his sdr at globaltuners.com, but I downloaded it and it included those specific times and frequencies for those dates. He didn't say but it's possible that he was the one keeping chobi.net's V24 log. And although he vouched for its accuracy it's of course possible that his April 27 log is in error. He also has the 5700/16:00 transmission entered for the 15th.

I'm hoping to get a PA0RDT antenna as it seems to be the best option for my limited space, better than folding dipoles and the like, and hope to be able to hear V24 directly when I get that set up. I have been able to hear the music deep in the static a couple of times, which is hardly satisfactory.

As always, thanks for sharing your experience with us.

[Token]

I agree that the chobi.net chart is at times suspect, but I know from experience that some of the entries were logged at the precise time of transmission (e.g., a 5790 transmission at 1500 on April 26 being entered at on April 26 at 1500 - I was trying to hear it and hitting refresh and seeing the page updated. Important to note that this isn't an exact example because I never wrote down the dates when I saw that happen, just using it as a possible example.) The point being that sometimes it was updated "live," at other times a week would pass before they updated it.

Yes, I have seen this also, sometimes the chart is updated before the station completes its transmission, other times it is weeks later before a specific entry is updated, even if other chart updates occur before the delayed ones show up.

Anyway, V24 observer "Moomin" has a chart available for download. (He said that you told him that you've been following V24 since 1978, so we do respect your expertise on the subject of this station.)

I first heard the station, or at least one matching the format and rough habits, in the 1970's, I don't remember the exact year.  The earliest log entry I still have is from 1978, but I think I heard it before that.  That was well before ENIGMA started using their identifiers and had established a database, so it was not called V24, or indeed anything really specific.  I have always paid a little attention to this station (and a few others) over the years, but I started watching this station closely in 2009.  From 2009 on I have hundreds, possibly thousands, of recordings of this station, and I have near daily spectrum recordings from 2010 on.  At a rough guess I have missed fewer than 50 days of data in the past 6 years, and most of those missed days are from equipment failures / power outages.

I'm hoping to get a PA0RDT antenna as it seems to be the best option for my limited space, better than folding dipoles and the like, and hope to be able to hear V24 directly when I get that set up. I have been able to hear the music deep in the static a couple of times, which is hardly satisfactory. 

If you are in a high noise environment a physically small active antenna, like the PA0RDT, might not work out well.  Personally I like the active loops, such as Wellbrook and Pixel, better than the mini whips.  With a loop you have the option of turning the loop so to null some local noise sources.  Not saying there is anything wrong with the PA0RDT for a limited space application, just saying I like the loops better.  If you have the space full sized, resonant, antennas are almost always better though.

T!

[MDK2]

If you are in a high noise environment a physically small active antenna, like the PA0RDT, might not work out well.  Personally I like the active loops, such as Wellbrook and Pixel, better than the mini whips.  With a loop you have the option of turning the loop so to null some local noise sources.  Not saying there is anything wrong with the PA0RDT for a limited space application, just saying I like the loops better.  If you have the space full sized, resonant, antennas are almost always better though.

I'll take that into consideration. I don't think my environment is actually that noisy for an urban setting. I have copied quite a bit with just the Satellit 750 and random wire, straight into the side with no baluns or coax, and noise isn't often a hindrance. I have read that PA0RTD's need to be very properly grounded or else noise is an issue. Do that and get them up high (and I plan to go past the legal limit, not too much to be noticeable...) and they should be good. But I'm also going to homebrew a loop (it won't be active, natch) and see what works. Those active loops aren't cheap, and money is also a consideration.

Thanks as always for the insights and tips.