Category Archives: meteor scatter

Contest + Meteors + SDR = Fun!

The first weekend of May each year hosts a Europe-wide VHF/UHF contest. It’s one I always look forward to: there’s a decent chance of tropo on some of my favourite bands (unfortunately not this year); a slim chance of Es (definitely not this year!); and, most reliably, it’s around the peak of the Eta Aquariids meteor shower.

Eta Aquariids meteors are quite unusual because they are relatively swift (at 66.9km/s) compared with many other shower meteors. When seen visually, they leave long and persistent trains in the night sky. In a similar fashion, from a radio perspective they often result in long and intensely strong “bursts”. Combined with a decent peak hourly rate of 40 and a lot of QRO, well-sited stations all over Europe, this can make for some interesting listening! This year did not disappoint with many bursts heard on 144MHz, some lasting tens of seconds.

A step up from simply tuning around searching for meteor-scatter bursts is to use a Software Defined Radio (SDR), with appropriate software, to record a portion of spectrum to hard disk for a period of time. This data can then be viewed after the event, tuning across the recorded spectrum as if it was in real-time. As an example, I used Simon Brown’s excellent SDR-Radio suite (Version 2.3 in my case) to do just that at various points through the weekend, capturing several very good meteor bursts.

Included below is a video of me using SDR-Radio’s data file analyser to play back signals captured during one good burst on 144 MHz, which I’ve annotated with information about each station received, wherever possible.  Enjoy!

msburst
This browser does not support flash! You can download the video instead.

This data was captured in IO51vw using an 11el F9FT antenna at 6m a.g.l., azimuth 095 degrees, a mast-head preamp into an active 0dB loss splitter, feeding an RTL SDR dongle on one port. The recorded spectrum was originally 1MHz wide, centred at 144.280MHz, but I’ve used the data file analyser to zoom in such that the spectrum now covers from approximately 144.150 MHz to 144.410 MHz.

 

Update…

I thought I’d better post an update, having not posted anything for a while; the reason being that not a lot has been happening!

The Eta Aquariids meteor shower peaked on the 6th of May, producing some fine, long meteor bursts: The best I heard was one from DF1JC (JO31) on 2m that apparently lasted for over 130s at S9, and there were a number more from various people lasting 20/30s. The one downside of this shower was quite a low meteor rate, so we had to be patient especially over the longer distances. We’re actually at the bottom of a twelve-year cycle for this shower, so the rates should only get better over the next six years. I didn’t work anything sensational, but was very happy to complete with the Camb-Hams DxPedition, GS3PYE/P (IO68ul) for a new square.

The much-anticipated Sporadic E (Es) propagation has started in Europe, giving a few lucky people 6m links into TEP and F2 propagation further south. The only thing of interest heard here recently was the ZD8VHF (II22TB) beacon on 50.0325MHz at around 21z on 5th May, via an Es link into evening TEP, weak but audible:

zd8vhf 6m es+tep
ZD8VHF/B on 50.0325MHz heard at EI3KD on 5th May 2014 @ 21z

East and Northern Europe have had the first Es opening of the year on 2m, on the 13th of May – one of the favourite dates each and every year!

On 2m EME I’ve worked a few new initials (now up to 114), including I3EVK (JN66) and IK7EZN (JN90) both in new squares for me. However, a highlight was a contact with the Team Athletico expedition to Senegal, 6W/PE1L (IK14jp):

6WPE1L qso EI3KD, 2m EME, JT65B

6W/PE1L qso EI3KD, 2m EME, JT65B

A lot of concentration and patience is required for this sort of EME contact, given I was trying to work a modest, albeit highly optimised, two-yagi station with my single short 11 element yagi: I missed a few opportunities at the start of the expedition because, for a few days, they had a local obstruction causing a minimum 7 degree horizon, which meant the moon was already above my ground-gain peaks by the time it “rose” for them. However, when I began to get common windows I concentrated on them at every opportunity. I heard/decoded the expedition quite a few times but was, unsurprisingly, unable to break their pileup during the very short times when my ground-gain was enough to see them – a maximum of two periods each about twenty minutes long after moonrise, with no possibility at moonset due to local noise. In the end the time spent paid off and after many failed calls and one or two near misses we finally made a fine contact. The team can’t be thanked enough for their unsurpassed dxpedition and operating skills – thanks once again guys!

Hopefully my next update will be reporting a massive 2m Es opening, or some extraordinary tropo – we live in hope!

A good start to 2014 (apart from the weather)

Firstly, I’d like to wish everyone a very happy new year – all the best for great 2014.

The weather over the last few weeks has been dreadful, so thoughts are with anyone adversely affected. As I type, we have yet another storm (“Christine”) passing through with 125km/h winds just offshore to the south of us, thunder and lightning, local flooding and damage… We could do with a break now, please!

On the radio side, things have started off a little better. I’ve worked a couple of nice EME initials, i.e. ZS9MADIBA, commemorating the life and recent passing of Nelson Rolihlahla Mandela, and RA22AL, one of the 2014 Russian Winter Olympics special event stations.

The Quadrantids meteor shower was predicted to peak at around 19:30z on January 3rd and is one of my favourites, with a reliably strong peak, albeit usually fairly short-lived. I concentrated on long-distance skeds (e.g. > 2000km), especially with stations that I’ve tried and failed with before (special thanks to Dule, YU7TRI, and Zdravko, E77AR, for many previous attempts), and chased a few new squares that were closer in.

I was delighted with the results this year, completing with the following (bold = >2000km, red = new locator):

02/01/2014 09:56 S58M JN76JC 1794km
02/01/2014 12:43 IK2DDR JN55GN 1544km
03/01/2014 09:47 I3MEK JN55SJ 1619km
03/01/2014 13:21 SM7THS JO76WU 1647km
03/01/2014 15:03 LY2BUU KO15XH 2141km
03/01/2014 15:27 LY2R KO15VS 2128km
03/01/2014 16:39 OH1MN KP10FO 2104km
03/01/2014 17:37 OH2NHP KP10RN 2157km
03/01/2014 18:25 OH4LA KP20LG 2232km
03/01/2014 21:30 DL8II JN49GP 1205km
03/01/2014 21:39 DH0LS JO51UA 1383km
03/01/2014 21:41 DL2RMC JN59IF 1369km
03/01/2014 21:53 S57VW JN76HD 1780km
03/01/2014 21:54 OK1TEH JO70FD 1596km
03/01/2014 21:57 DL3YEE JO50LX 1333km
03/01/2014 22:23 IW5ECS JN53GQ 1670km
03/01/2014 22:58 YU7TRI KN04KV 2272km
03/01/2014 23:35 E77AR JN94AS 2088km
04/01/2014 09:48 DG0JMB JO60LV 1472km
Quadrantids 2014 QSO map

Quadrantids 2014 QSO map from EI3KD, IO51vw

There were several exceptional contacts, including Dule, YU7TRI (KN04kv/2272km), who’s bursts can be heard in the links below:

Note 1: The second clip (with “RRRR”) was not automatically decoded by WSJT, probably due to significant doppler on the signal. It required a lot of manual mouse-clicking around the burst!

Note 2: There are a number of very short breaks in the audio, which were caused by a poor internet connection to the remote rig.

Reflections from Pasi, OH4LA (KP20LG/2232km) were also good, with eight bursts similar to this one:

Top burst prize goes to Timo, OH2NHP (KP10RN/2157km) for a great burst peaking S9, containing finals – a nice way to complete a QSO!

Links to the .wav files that can be opened directly in WSJT are here: YU7TRI_140103_223700.wavYU7TRI_140103_225200.wavOH4LA_140103_180300.wavOH2NHP_140103_1737001.wav

Problems with the Meteorscatter-Sprint contest?

The Meteorscatter-Sprint contest takes place, each year, for a period of 48 hours around the peak of the August Perseids meteor shower. The rules don’t state any specific reason for the contest but, apart from providing the usual contest thrills, one assumes one of its main aims must be to promote activity?

From my perspective, it became apparent during 2013’s Perseids shower that this contest is having a somewhat negative impact, especially (but not only) when it comes to attempting ODX (extreme distance) contacts. I’ll try, as best I can, to explain…

Firstly, there is really no need to promote activity at the very peak of the year’s best meteor shower! The August Perseids is widely known to be very reliable and has been a focus of activity, including expeditions, for decades. Any promotion of activity would be far better targeted a week, or even a few days, before or after the peak: Conditions are often excellent during these times, but activity (i.e. stations “on the air”) has never been anywhere near as good as at the peak – this can only be partly due to the current sprint contest because it has been true for many, many years.

The August Perseids provides a high ZHR (Zenith Hourly Rate) at a quite predictable peak time, that makes it ideal for attempting extreme distance QSOs. However, even at the very peak of the shower, distances significantly greater than 2000km will often take a long time to complete, perhaps upwards of an hour. Unfortunately the sprint contest implicitly encourages entrants to only attempt QSOs that will take very little time to complete: It is, after all, a “sprint” and the scoring system is based purely on the number of contacts made, so it’s natural that entrants want to make contacts at the highest possible rate – who can blame them? I’m not sure it’s really possible to add enough bias in the scoring system to make it worth people’s time attempting QSOs over extreme distances, but if the contest is to remain at the peak of the shower then it should be considered… please!

The end result is that it becomes intensely frustrating to be receiving meteor scatter signals from several stations who are more than 2400km away, but have no chance to contact them because they are only interested in “quick and easy” QSOs. Of course, as it stands, once the contest is finished they are then free to try an hour-long sked, but the irony is that the peak of the shower has then passed and a QSO is not possible…

I make no bones about the fact that I’m a DX-er and therefore have my own biases. I enjoy stretching the boundaries of what is possible at VHF and I think, in general, contests are a great way of achieving that purpose. Unfortunately, in my opinion, the Meteorscatter-Sprint contest does not!

Perseids 2013 report

I’m happy with my Perseids results this year, with sixteen new locators (easy to come by with my low total) and three new DXCC (OH0/DM2ECM, YL2AO, HV0A), but it didn’t seem like a great shower – certainly not one of the all-time greats. There was also a somewhat negative impact at this QTH from the Meteorscatter-Sprint Contest but more of that in another blog, coming soon…

According to the International Meteor Organisation, the Perseids peaked this year at around 17:00z on August 12th, two or three hours earlier than originally expected. Radio observations here would tend to indicate some sort of peak at that time but it seemed weaker than the diurnal effect, when local 6am is generally best due to the fact that the Earth is revolving into the path of oncoming meteors at that time (the Earth’s rotational speed is added to the direction of travel around the Sun at dawn, and subtracted at dusk), so the relative speed is highest. In fact, the Sodankylä Geophysical Observatory’s real-time meteor radar (note: link is to current data, not from Perseids peak) showed a much higher radio rate at around 9z on each day from 11th to 13th August, than at 17z on the 12th.

The best way to describe the shower this year was “clumpy”, or “like trying to start an old car on a damp morning”, i.e. it never really got going. Every now and then there would be a series of good reflections, maybe of several seconds each, but often there would follow a period of silence for a considerable time, maybe tens of minutes. It would have been easy to describe these silent periods as “worse than random”, if that actually meant anything! If one was lucky enough to get the timing right a QSO could be completed quickly, otherwise patience was required. Unfortunately, the reflections never became sustained enough for a significant amount of SSB activity, which used to be one of the trademarks of the Perseids, but I did manage a couple of SSB QSOs for “old time’s sake”…

Looking at the log, a quick summary of QSOs measured by distance shows three over 2100km (ES3RF/KO29if/2194km, IC8TEM/JN70cn/2123km, SK2AT/KP03bu/2105km), six over 2000km and eleven over 1900km – not bad!

A blog from me wouldn’t be complete without at least a couple of audio clips 😀 Here are a few nice bursts from OH0/DM2ECM (JP90wg/1951km) sending me R26, including one that lasted an entire 30s period:

OH0/DM2ECM 12/08/13 17:22z
\"OH0/DM2ECM\" from 2m ms by ei3kd.

OH0/DM2ECM 12/08/13 17:30z
\"OH0/DM2ECM\" from 2m ms by ei3kd.

OH0/DM2ECM 12/08/13 17:31z
\"OH0/DM2ECM\" from 2m ms by ei3kd.

(.wav files for direct decode in WSJT: DM2ECM_130812_172200.wavDM2ECM_130812_173000.wavDM2ECM_130812_173100.wav – right click and “save as”)

… and this is a nice burst from UA2FT (KO04lt/1946km) who only runs 50 Watts, sending me 26:

UA2FT 12/08/13 18:14z
\"UA2FT\" from 2m ms by ei3kd.

(.wav file for direct decode in WSJT: UA2FT_130812_181400.wav – right click and “save as”)

Finally, below is a map of contacts made from this QTH around the 12th August, plus or minus a day or two:

Perseids 2013 QSOs

Contacts made by EI3KD around the peak of the 2013 Perseids

Heading south!

Today was spent with the antenna heading mostly to the south. After lunch I checked the beacons and heard ED1ZAG/B (IN53re/973km) at a stable 529, although there were no other signals on the band at that time. I spotted the beacon on the cluster and shortly after Pedro EA1FCH (IN63in/933km) appeared calling cq on cw on 144.300MHz, so we had a quick QSO. Pedro then moved to 144.186MHz and started calling using JT65B, and we had another quick contact to check everything was working ok: It seems Pedro has something like a +40Hz drift, strangely in two 20Hz jumps, during his JT65 tx period but WSJT’s AFC coped with it fairly well.

A little later, the ED1ZAG beacon had improved (audio with two complete keying cycles): 

At around that time I heard, quite weakly, the new Spanish beacon ED1YCA/B on 144.445MHz, which is in IN73al/955km: That looks like it’ll be another useful propagation indicator!

Because the tropo seemed to be reasonable, At 16:00z I asked Domingo, EA8TJ (IL18rj/2707km) if we could try a JT65B sked. We arranged to run on 144.186MHz, and he started transmitting straight away. I was still setting up the rig for digital when I heard this (audio starts T+30s into Domingo’s period, the four “blips” are me changing rig settings): 

Amazing! Clearly digital tones followed by Domingo’s CW ident “EA8TJ”, but what was the propagation mode? I doubt it was tropo because it didn’t persist, and I also doubt it was meteor scatter because there doesn’t appear to be any doppler. The most likely thing is a brief Sporadic E enhancement, especially considering the band was to open to the south just over an hour later, albeit on a much more easterly path? Anyway, there was no tropo detected over a period of about 15 minutes, although we both heard further pseudo-ms from each other.

I continued to monitor 144.300MHz and at 16:50z heard Jose, EB1DPB calling on ssb, very weakly. After a couple of calls I got his attention and we had a nice QSO, with the signal increasing all the time. By the end, it was quite good: 

To round off a fascinating afternoon there was a reasonable Sporadic E opening at around 17:10z, but the main geometry landed signals from EI on the north coast of Algeria (7X). Ever the optimist I tried many calls on 144.300MHz and 145.500MHz (FM), but to no avail 🙂 The only station heard, very briefly at 59, was Juan EA7AJ (IM87cs/1612km).

 

Another day on 2m, or was it 20?

Today turned out to be quite busy on 2m…

It was a good start to work Jurgen, EA6/PE1LWT (JM08ox/1614km) via meteor scatter: Reflections were very good, especially considering Jurgen is using 100W to an 8el. He’s mostly operating on 144.358MHz for ms.

There were quite a few contest stations out for the weekend, so I had a quick look around on tropo. In fact, I couldn’t hear much except a couple of French stations, including F6KBF/P (JO10HE/781km) who was a pretty decent signal: 

Later in the afternoon I saw that the TM77A expedition was QRV, in IN77tw. Once they had their antenna this way it was an easy 59 SSB QSO, with the 522km path almost completely over sea.

The whole day had looked very promising for Sporadic E, and during the QSO with TM77A I noticed that Band 2 was completely full of stations, mostly from Italy. After a few calls from myself and my (very close!) neighbour Tom, EI4DQ, the first signal appeared on 2m at around 16:10z. I had just a few QSOs:

02/06/2013 16:10 I2PY JN55NB 59 59 SSB ES 1609km
02/06/2013 16:11 IW3HRT JN55TG 59 59 SSB ES 1628km
02/06/2013 16:16 F0FUT JN37JO 59 59 SSB ES 1177km
02/06/2013 16:17 I3LGP JN55VK 59 59 SSB ES 1629km
02/06/2013 16:18 HB9DFG JN37SM 55 57 SSB ES 1230km

(Also heard: HB3?, HB9MFM/JN37te)

Some audio from the later part of the opening is here: 

Towards the end of this opening I heard 9A3DSL (JN65th/1756km) call Tom, but didn’t hear him again: 

The cloud then moved to the north and east, at which time I think the MUF was still above 144MHz but propagation wasn’t possible from here because the reflection point was too close. However, at around 17:45z the band opened up again, to the east:

02/06/2013 17:48 SP2MKO JO93CB 59 59 SSB ES 1782km
02/06/2013 17:52 SP4MPB KO03HT 59 59 SSB ES 1932km
02/06/2013 17:54 DK1CO JO63SX 59 59 SSB ES 1468km

Not too many QSOs, but some big signals! I’ve included quite a long recording here (warning, it’s 12Mb), which is in “real-time” so you can have fun searching for the signals!

Thankfully the weather here is great at the moment and I managed to fit in some gardening time with my wonderful XYL between all the DX, phew!

Lots of doppler!

I monitored a meteor scatter schedule between Gordon, GW6TEO (IO71lp) and Peo, SM5EPO (JP80mc/1802km) this morning and conditions seemed quite reasonable. Their QSO was more-or-less completed when I received an unusual reflection from Peo: It lasted about seven seconds, but changed frequency by almost 1kHz in a fairly linear fashion over that time. I’ve heard bursts with lots of doppler quite often, although 1kHz is pretty large, but the normal burst characteristic is a very short period of doppler followed by a significantly longer period with none.

I checked with Peo that he hadn’t tuned his VFO at all (and neither did I). I also eliminated the possibility of a reflection from the International Space Station (ISS) because it was over the Middle East at that time. So, the reflection must have been from some other large space object crossing the path at a relatively (by meteor standards) low speed?

Here is the WSJT display of the burst, which appears at the start of the period, fades a little, then reappears stronger at about T+6 (note: the time displayed in the decoded messages in this image is accurate, other times are incorrect):

SM5EPO unusual doppler

SM5EPO unusual doppler

And here is the SpecJT display, which shows it in more detail (note: the times displayed in this image are incorrect, because it was generated after the event):

SM5EPO unusual doppler

SM5EPO unusual doppler

And here is a zoomed image of the burst:

Closer view of burst

The .wav file saved by WSJT can be downloaded from here (right click and “save link as”). This file can be opened directly in WSJT, or simply played as an audio file. I found I had to left-click on the burst to get a decent decode.

Not quite an average day on 2m…

The 18th of May turned out to be interesting, and reminds me why I’ve always found 144MHz to be so fascinating!

The day started with an early Es opening to Italy, resulting in the following QSOs:

18/05/2013 09:00 I2PY JN55NB 59 59 SSB ES 1609km
18/05/2013 09:01 IW4ARD JN64FD 59 59 SSB ES 1754km
18/05/2013 09:07 I2ARQ JN55NA 59 59 SSB ES 1612km
18/05/2013 09:19 IW2BNA JN45ON 59 59 SSB ES 1455km
18/05/2013 09:21 IZ4MAO JN54GQ 59 59 SSB ES 1597km
18/05/2013 09:23 IW2NNZ JN45SN 59 59 SSB ES 1476km
18/05/2013 09:27 I4TSB JN64DA 59 59 SSB ES 1752km
18/05/2013 09:30 IW4BET JN54PG 59 55 SSB ES 1672km

2m Es QSO Map 18/05/13

2m Es QSO Map 18/05/13

A bit later I was QRV for moonrise, and managed to work a new initial:

18/05/2013 13:43 JR3REX PM74LQ RO RO JT65 EME 9735km

After the Moon had risen too high for my fixed-elevation antenna, I tried a tropo test with Jerome, F8GGD, in IN95: Unfortunately this didn’t work, but as we were trying Dom, F6DRO, said he could hear me weakly. Dom and I then tried and we could both hear continuous signals right on the noise floor, in fact enough to complete a contact on CW with a bit of “brain averaging”. I was very surprised, because Dom is in JN03TJ and 1201km distant! It’s really too far for troposcatter, but I suspect there was some tropo enhancement (i.e. ducting) on the path.

Oh, and I also heard DK1FG’s (JN59op/1384km) complete QSO with M0BAA/P, which I suspect was via Es-enhanced meteor scatter, just to add another propagation mode into the mix 🙂

Poor EME conditions, but MS is ok

EME conditions have been poor for the last few days, and remain so. A quick look at F1EHN’s EME planner (part of his free EME System V7 software), shows why:

emeplan130513

 

Todays data (13th May 2013) is on the very left of the graph. All the lines, except declination, are down in the darker area, indicating significant degradation of the ideal path loss. The next reasonable opportunity looks to be in a few day’s time.

I tried a few calls this morning at moonrise and just about made it onto LiveCQ, about 9dB worse than ideal. Unfortunately, I struggled to copy an answer from Sergej, RN6DJ, and we consequently failed to complete… Next time Serge!

Meteor Scatter remains good now that the summer showers have started to kick in. A try with Moma, YU1EV, was successfully completed at around 09z, at a very reasonable distance of 2246km (IO51vw-KN04cn). A later attempt with Peter, SM2CEW, failed – but some reflections were heard at a distance of 2293km, so there’s definitely a chance in the next major shower.