Category Archives: 144MHz

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
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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.

 

More transatlantic aurora

On the 17th December, shortly after 09z, there were two solar coronal mass ejections (CMEs) in rapid succession, both of which directed at least some of their ejecta towards the Earth. This was fair warning of the possibility of aurora due some time on the 19th, depending on exactly how fast the material was traveling. The strength of any aurora would also depend on the alignment of the Interplanetary Magnetic Field; for maximum effect we would need a strong southerly component.

As anticipated, the CMEs passed the ACE spacecraft at 13:05z on the 19th, hitting the Earth approximately one hour later. The good news, from our point of view, was that the IMF had a significant southerly component for much of the time, resulting in excellent coupling of the CMEs into the Earth’s magnetic field causing a nice strong aurora!

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Tropo on the edge…

It’s been some months since we’ve seen any sort of decent tropo opening on VHF/UHF, in this part of Europe at least. However, there really was no excuse for being unaware of this one in advance because the forecasting websites (F5LEN and Hepburn) had been predicting something nice for the end of September for at least week prior. It turned out to be exceptional!

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Super Atlantic tropo!

I’d been keeping an eye on the F5LEN and Hepburn Atlantic tropo forecasts prior to the 20th of May because they looked promising for good propagation towards the south:

Hepburn North Atlantic forecast 06z May 20, 2015

Hepburn North Atlantic forecast 06z May 20, 2015

F5LEN Atlantic forecast 00z 21st May, 2015

F5LEN Atlantic forecast 00z 21st May, 2015

Lots of bright colours over much of the North Atlantic! There looked to be some possibility of a repeat of Dave, PJ4VHF’s incredible reception of the Cape Verde beacon, over a distance of some 4700km (and perhaps further?), as well as a north-south path touching on Ireland.

Up until lunchtime on the 20th there was nothing other than a slight enhancement on my AIS receiver (a useful propagation tool at 162MHz, online at MarineTraffic) showing ships slightly further south of Cork than usual – certainly nothing exceptional. I wasn’t even hearing the stalwart ED1ZAG beacon in IN53 but the forecast maps were marginal for that direction.

At approximately 14:35z, a weak cw-keyed signal appeared just very slightly above 144.436MHz, rapidly becoming strong enough to identify as D4C in HK76mvThe Monteverde Contest Team’s beacon is at a distance of some 4165km from EI3KD, with a tolerance of five kilometers or so, which probably makes it the furthest tropo distance yet heard from within IARU Region 1.

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“St Patrick’s Day Aurora”, 144MHz

The aurora of 17th March 2015, St Patrick’s Day, was a superb event: It was good enough to propagate signals on 50MHz across the Atlantic, which I found particularly interesting. Unfortunately I haven’t had much time to get anything in the blog about conditions on 144MHz, so here’s an effort to get at least something recorded!

The QSO map for 2m looked like this:

"St Patrick's Day" Aurora, 144MHz

EI3KD (IO51vw) QSO map for 144MHz during aurora on 17th March, 2015

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Cloudy, with a chance of DX – super tropo.

A baby 70cm station is born, ready for action!

EI3KD antennas

2m (11el F9FT) and 70cm (19el F9FT) at EI3KD

Some months ago I added a 432MHz 19el F9FT antenna to the mast (approximately 4.5m a.g.l.), with the help of G4CLA – thanks Pete! My FT857D is capable of 20 Watts output on 70cm, but I did find an old sspa that, with a reduced drive from the rig, bumped it up to a massive 30 Watts! Every decibel counts, right? Anyway, the sspa’s built-in preamp was probably a small improvement over the rig’s front-end. Even with such a small set-up I’ve managed to give away a few points in the RSGB UKAC 70cm contests, and also had a few DX contacts during brief spells of enhancement. I also have a higher power sspa to modify for 432MHz, but that’s another story.

Since added the 70cm antenna I’ve been looking forward to a decent tropo opening, and early February wasn’t going to disappoint! Apologies for the length of the blog that follows, but it was an exceptional tropo opening…

Worked and heard maps 8-12 Feb 2015

144MHz worked and heard, 8-12 Feb 2015

144MHz worked and heard, 8-12 Feb 2015

432MHz worked and heard, 8-12 Feb 2015

432MHz worked and heard, 8-12 Feb 2015

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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!

Aurora!

Who’d have thought, 11 (or even 22) years ago, that aurora would be so rare this time around? There have been hardly any openings this far south, but we’ve had a couple in recent times.

On February 23rd, I worked Clive, GM4VVX in IO78ta at 17:38z. For some reason Clive was hearing me a lot better than I could hear him – I do have a lot of band noise the nearer north I beam, but it still seemed non-reciprocal?

On February 27th we had a slightly better opening. I worked a couple of Gs and GMs, but best dx was to SM4IVE (JO79sd/1682km) and SM7GVF (JO77ga/1565km) – all QSOs at a heading of 035 degrees.

The signals from SM7GVF were quite strong at times:

sm7gvf 2m aurora 270214
"sm7gvf 2m aurora 270214" from Aurora by ei3kd. Released: 2014.

SM4IVE was weaker but still peaking around 54a. I haven’t found him on my recording yet (it may have been off at the time) – if I do I’ll add it to the playlist.

A small milestone…

Conditions have been poor and the weather has been terrible, but I reached a small milestone: I completed a moonbounce QSO with my 100th unique station (initial), and have since gone on to work a couple more. I’m happy with that, given my ridiculously small antenna and the fact that I’m limited to moon-rise only. The low height of the antenna above ground (approximately 6 or 7m) results in only two usable ground-gain peaks (around 2.5 and 12 degrees elevation), so my windows of opportunity for EME are indeed very limited!

I’m sure there are people with similar systems to mine that have never considered EME, perhaps thinking their antenna is too small. Please do give it a go! As an incentive, here’s a few statistics from my 102 unique EME stations:

  • Number of EME DXCC: 34 (15 are unique to EME)
  • Number of EME Squares: 88
  • Number of EME Fields: 22
  • EME best dx: ZL3TY, RE57OM, 18956km

I’ve also heard quite a lot more stations that I’ve not yet worked, including a better ODX, so there could be more to come…

I arbitrarily chose the 100th initial as a target to reach before making any changes to the system. Now that’s done I can think about what to do – current plans are to add 70cms, and perhaps add elevation and/or a second 2m antenna.

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