Wow! I haven’t posted for quite a while, perhaps I’ve too busy actually being “on the air”, rather than spending all my time on various forums moaning about FT8 or some other nonsense? Anyway, I’d better generate a few updates and here’s the first.
First of all, of course, is the fact that I’ve finally made a 2-way qso with D4 on 2m. D4Z, in fact, operated by Mark, EA8FF, on-site in Cape Verde, HK76MU. This was on 5th August 2018 at 16:15z, using CW at 4163km. I was extremely happy to make this contact: it’s been a personal ambition of mine since I first became interested in VHF way back in the 1970’s – an awful long time to wait! At one time I even had genuine thoughts of living on Cape Verde to explore the V/UHF possibilities, although that never came to fruition…
Video or audio at both ends are here:
As for the qso, it was only a matter of time, having heard the beacon so many times in the past. For that very same reason, I personally didn’t make much of a “song and dance” about the fact it was, at that time, a distance record; I had no doubt it would easily be exceeded, sooner or later. Despite that, our qso did receive a lot of publicity, which was a great help in encouraging others to be aware of the possibilities. Since that day the distance record has already been extended several times by D4Z and D41CV, and it will be again, thanks to the great efforts of the team at D4C. I continue to be excited at just how far we, as a V/UHF community, can push the limits and will strive to make sure we do just that!
My own target now is to work towards a D4 qso on 70cm. Rumours are that would be a world record, not that I care 😉
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!
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.
The 6m transatlantic path via aurora has been reported before by others and is certainly nothing new, but I’m beginning to wonder if it’s more viable than many might think. We had another decent aurora on 31st December, most of which I missed due to the New Year’s Eve celebrations, but I decided to check westerly conditions when I returned home sometime after midnight.
Once again I was surprised to find the VE4ARM beacon (EN09at, 6011km) at a good strength at approximately 01:40z (Jan 1st) followed about ten minutes later by VY0SNO (FP53rs, 3653km). The opening was again quite short but there’s a possibility the path might have also existed earlier in the evening? After I had spotted the beacons on the dx cluster, VE4ARM was reported by Tim, G4FJK in IO80 at a great distance of 6346km, and the VY0 beacon was reported from PA and DL.
One fascinating little snippet: This time I managed to grab a decent recording of VY0SNO just before it faded. Listen very carefully to this clip, and you may be able to detect a sudden doppler shift of about +10Hz, 21.5 seconds in, coinciding exactly with a steep drop in the signal strength. I think that helps visualise the auroral-Es path dynamics rather nicely!
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!
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!
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
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 HK76mv! The 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.
My main effort for the May UHF/SHF contest weekend this year was to activate IO51 on 3cm (10GHz). I had tried to do the same last year but discovered a problem with the transverter’s local oscillator (LO) producing too little power, meaning the activity had to be aborted. Since then, with the help of John EI2FG, I had fixed the LO and everything seemed to be working fine.
Unfortunately, I can only erect the 3cm station on a temporary basis and it is quite a lot of work but, if I’m going to try it at all, the SHF contest weekends are the time to do it! Luckily I had a few contacts which made it worthwhile – in fact I had more success on 3cm than on 70cm where (admittedly with very little time spent there) I worked the onestation I heard all weekend…
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:
EI3KD (IO51vw) QSO map for 144MHz during aurora on 17th March, 2015
I spent most of the afternoon and early evening hours during the “St Patrick’s Day” aurora on 144MHz but when that started to fade I thought I’d follow the aurora westwards, listening on 50MHz where I had already heard a few very strongly auroral GMs, peaking at an azimuth of around 320/330˚.
At 21:02z I heard a weak and different-sounding signal, certainly auroral but more “Tone 5” than “Tone A”. After peaking the signal at an antenna azimuth of approximately 295˚, it turned out to be K2PLF in FM19 at a distance of 5272km! Unfortunately my 100 Watts wasn’t enough to be heard by him but it was the start of a fascinating couple of hours, listening to many weak signals popping up as stations in the USA and Canada called and worked each other.
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…