It's been a pretty dismal two days for propagation on the 28 MHz band.
Sat 10th Apr 2021 - This was one of those rare days where I didn't hear one single FT8 signal on the band. I nearly always hear something as I listen to the band from about 8am to 11pm every day.
The result is always the same... I check the VSWR on the antenna to make sure it's working ok! All was good so it was just one of those days.
Sun 11th Apr 2021 - This day wasn't much better but there were a few signals including two from Brazil.
I did hear 9J2BS in Zambia and ZD7JC on St.Helena Island in the South Atlantic but those reports didn't appear on the PSK Reporter website.
While the Spring months tend to be the quietest in terms of meteor showers, things start to pick up at towards the end of April every year. The peaks of the various meteor showers are good times to check for bursts and pings of radio signals on the VHF bands.
I have put together a calendar which contains a list of most of the current meteor showers. The list below covers from April 2021 to January 2022.
There was a weak Sporadic-E opening on 28 MHz on Thursday the 8th of April 2021 with a total of 20 stations heard on FT8.
Some of the Spanish signals were actually audible and weren't just buried in the noise. I tried two scans of band when the FT8 signals were audible but I failed to hear any of the beacons.
In another two weeks time around the 23rd of April, there should be some decent openings on 10m.
Foreword... AIS (Automatic Identification System) is used by ships to identify their location by sending out a signal at 162 MHz which is pocked up by other ships and shore stations. There is a growing community of enthusiasts near coasts around the world who monitor these signals and feed the decoded signals into websites that then display the positions. AIS signals which are a few watts in power act like beacons and can be used by radio amateurs to show if there is any tropospheric enhancement on the VHF bands... de John, EI7GL
Propagation Monitoring 2m Band with AIS Data from Vesseltracker.com ...by Jörg, DM4DL
I'm trying to use the ships' transponders on 162 MHz +/-25 kHz as beacons for the 144 MHz 2m band. My first AIS receiving antenna is on the island of Neuwerk, 15 km from Cuxhaven.
For 5 years I was able to inspire some HAM radio operators and meanwhile a partnership between the company Vesseltracker and Gabriel, EA6VQ, the operator of DXMaps is planned.
As a test, the Vesseltracker data of some AIS-RX are already being forwarded to DXMaps.
Please check whether you would like to participate in the community with your location?
Example of enhanced VHF conditions in the eastern Mediterranean
The last few days have been very poor on 28 MHz with hardly any signals heard on the band. There is no real sign of the Summer Sporadic-E season kicking off although that should all change towards the end of April.
On Wednesday the 7th of April 2021, I heard ZD7JC on St.Helena Island in the South Atlantic as well as a handful around Europe.
I suspect there may have been a weak area of Sporadic-E to the south of me and then onto to St.Helena via either F2 propagation or TEP (Trans-Equatorial Propagation).
I saw TEP mentioned in the GB2RS news last weekend as part of the propagation forecast... "There have been some North-South paths worked on 10 metres via Trans-Equatorial Propagation or TEP, but these have mainly favoured stations located south of the UK."
This raises an interesting question... how can you tell the difference between F2 and TEP on 28 MHz? If it was 50 MHz then it's very likely to be TEP. But on 28 MHz? I'm not so sure anyone be 100% sure.
I have now updated my old DMR page to a new 'Digital' radio page.
Previously I used the page for DMR information in Ireland. The new 'Digital' page has links to all of my previous posts that contained any sort of radio related digital information.
Some of the areas covered are...
Digital modes for broadcasting like DAB, DAB+ and DRM
Frank, VO1HP reports that the VO1FN 144 MHz Trans-Atlantic monitoring station will be reactivated by the end of May 2021!
This SDR receiver will be using SDR Console V3 and WSJT-x and will report to the PSK Reporter website as VO1FN.
The station will be located in St.John's, Newfoundland and will use two stacked 5-element 144 MHz LFA-Q quad style Yagis from Innovantennas.
The antennas will be pointing at western Europe and the receiver will be listening on 144.174 MHz which is the FT8 frequency.
Trans-Atlantic on 144 MHz: Is it possible??? ...As can be seen from the map above, the distance across the North Atlantic between Newfoundland and Ireland is just over 3000kms. This is well beyond the normal 2300km or so range for normal Sporadic-E or meteor scatter and it seems unlikely that it would be spanned a marine tropo duct going all of the ways across.
I emphasize the work unlikely but it's not impossible. The North Atlantic is not noted for its fine calm weather and there is nearly always some low pressure system in there stirring things up.
What is likely to happen a lot more often are shorter ducts that are in the region of 1000kms in length and these could happen at either end although the eastern end seems more likely. If there is a Sporadic-E opening or a major meteor shower at the same time as a good 1000km marine duct then it may well be possible.
It seems to me that the path from Newfoundland to the north-west coast of Spain as the most likely one even if it is a bit further away. The number of stable marine ducts in that part of the Atlantic are higher than further north closer to Ireland.
According to the tropo forecast website of F5LEN, there is a chance of enhanced tropo conditions across the North Atlantic on the weekend of Saturday 3rd & Sunday 4th of April 2021.
While contacts at 144 MHz are probably unlikely, any suitably equipped stations in Ireland, the UK, France, Spain & Portugal might be interested in trying.
Frank, VO1HP reports that the following stations will be monitoring from Newfoundland mainly on the FT8 frequency of 144.174 MHz...
The distance across the North Atlantic is in excess of 3000kms and has yet to be bridged on 144 MHz.
* * *
Frank also reports that they plan to get their SDR Transatlantic Beacon Receiver site operational in May of 2021 when the antennas are taken out of storage.
In this three part series of posts, I am going to look at the 2020 logs of a very active Band 2 DXer and what they might suggest about propagation on the 88 to 108 MHz FM band. The posts are broken up into three parts... 1) Tropospheric Propagation, 2) Sporadic-E & 3) Meteor Scatter.
First off, a big thank you to Paul Logan who very kindly shared his 2020 Band 2 logbook with me and answered numerous questions that I had. Outside of his usual 'local' FM radio stations which he can hear under flat conditions, he logged and identified roughly 5,500 long distance signals on Band 2 in the year 2020.
Profile of Paul Logan... Paul is a very active listener of Band 2 radio (88-108 MHz) signals and has been logging stations that he has heard for about 30 years. He lives in Lisnaskea in Co.Fermanagh in Ireland and his location is shown in the map below.
Paul's location is far from ideal for listening to distant VHF signals. He has some local hills to the east as well as the hills and mountains in Scotland, England and Wales as a further obstruction.
Equipment... For the 2020 logs, Paul used an SDRPlay RSP1 & RSP1A.
In recent years, software defined receivers have transformed FMDX listening as signals can now be seen on a computer screen as well as being heard. This allows a user to visually check for any unusual signals and can then go investigate it. One of the most impressive features is the ability to record sections of the spectrum and a user can then go back later to listen for anything unusual.
For an antenna, Paul is using a Korner FM9 from Antennenland in Germany.
This antenna which is mounted 8 metres above ground level is highly regarded by many FMDXers in Europe.
2020 Tropo Log... During the year 2020, Paul heard and identified around 86 signals that were heard via tropospheric propagation. This mode of propagation occurs when signals are bent over the horizon by sharp changes between air layers with different temperatures and moisture content.
I have picked out 5 groups of signals of note which I have marked from A to E. Refer to the map below and then the horizon profile further down.
A - This group of signals from the north-west corner of Spain are in the region of 1200 to 1300 kms. The sea path from the south coast of Ireland to the north coast of Spain is very good for VHF propagation with marine ducting happening several times a year. These sea paths are usually the best for very long paths in excess of 500kms and sometimes the signals can be amazingly strong.
In the video below, Paul shows how he was able to hear a Spanish radio station on a small portable radio when the opening was at its strongest. With his main directional antenna, he was able to hear the Spanish signals for most of the day.
In the horizon plot below, you can see that the path to NW Spain at Paul's location is largely unobstructed with only a 1 degree elevation. This allows very low angle signals to arrive at his location.
B - This path to Brittany and Cornwall is similar in that the sea path helps and the hills on the horizon are quite low at about 1 degree elevation.
C - This interesting batch of signals came from Norfolk in the east of England, a distance of 600kms. These signals had a few obstacles to overcome including Paul's local hills as well as the Pennines running down the centre of England.
With the signals arriving at least 3.5 degrees above the horizon, the means of propagation may have been via an elevated duct in the region of 500m to 2000m above the earth's surface. While higher frequency VHF & UHF signals tend to propagate better inside of ducts, it went as low as 89.7 MHz in this example.
D - This cluster of signals from the Netherlands and Germany were interesting for a number of reasons. First off is the sheer distance... about 1000kms which is unusual for Band 2 tropo. I suspect that the sea path over the North Sea may have helped for a large part of the journey.
If you examine the horizon plot below, you'll notice that there is a gap in the hills due east (90 degrees) where the horizon has an elevation of about 2.5 degrees.
What's really interesting is that the paths from the four transmission sites fit exactly in the gap. The signal from the most northerly German transmitter is exactly at the left hand side of the gap. The signal from the most southerly Dutch transmitter is exactly at the right hand side of the gap. The four signals fit exactly like a glove which suggests that they are coming in just barely above 2.5 degrees above the horizon.
E - These signals from the Newcastle area were at a distance of about 370kms and again are coming in from an obstructed path. This one has the highest angle as it had to clear a local hill that was 4 degrees on the horizon.
Outside of the five examples shown above, most of the other signals were in the region of 150 to 300kms which is pretty typical for tropospheric propagation on Band 2.
What's also interesting are the signals that weren't heard. For example, there was no tropo from Scotland which Paul confirms is a very difficult direction for him. As can be seen from the horizon plot above, the local hill in that direction is 5 degrees and that has the effect of blocking tropo signals.
In conclusion... I hope this short analysis highlights the importance of having a low unobstructed horizon for hearing signals on Band 2 (88-108 MHz).
Having obstructions under 1 degree is best, under 2 degrees is acceptable but beyond that, the signals and paths get rarer.
Any local hill that is at 5 degrees or above is a show stopper for VHF tropo propagation.
The examples above would also apply to say the VHF aircraft band (118-136 MHz), the 2-metre amateur band (144 MHz) and the VHF marine band (156 MHz).
Normally the best advice is to have your antenna mounted as high as possible on the VHF bands so that the amount of obstruction on your horizon is reduced to a minimum.
Band 2 is a bit of an paradox in that the higher you put your antenna, the 'local' signals get stronger which in turn can mask the DX signals. It's really a case of finding out what height works best for your location.
There was a modest opening via F2 propagation on 28 MHz on Wednesday the 31st of March 2021 with Israel, South Africa, Mauritius in the Indian Ocean, Brazil & Uruguay.
Sometimes with FT8, my PC is decoding signals that I can't hear but some of these were very audible. I checked the beacon band and I heard the ZS6WAB beacon on 28.2048 MHz at about 419.
The solar flux was up to 80 today, a jump of 4 on yesterday.
There also seemed to be a weak opening to Europe with some UK stations making it through on what seemed like weak short skip.
One signal of interest was that of EI2CN who was -6dB even though he is 250kms distant. I noticed that BBC4 radio was coming in from Wales on 104.9 MHz earlier this morning so there was some tropo about. Was there tropo on 28 MHz as well? It seems like it.
The shutdown is scheduled for today the 31st of March.
During a visit to a local ALDI store on Monday, I noticed that they are now selling DAB radios are part of their 'Special Buys'.
These went on sale in Ireland on the 28th of March with the DAB network shutting down three days later.
Now in fairness to ALDI, these radios also have FM so they're not completely useless but it does have DAB radio in large letters across the front of the box.
These radios are probably produced mainly for the UK market and they just happen to be part of the offering in Ireland as well. This 'Special Buy' offering was also probably planned months in advance and the decision to manufacture, import and sell the radios was made months in advance of the decision by RTE to close the DAB network.
I just thought it was ironic that they started selling a digital radio on a Sunday and the digital radio network was closing down the following Wednesday.
There was a weak Sporadic-E opening on 28 MHz to the south of Spain for about two hours on the evening of the 30th of March 2021. While many of the signals were audible, they were quite weak.
I did have a listen around the beacon part of the band at one stage but I couldn't hear anything.
In 2020, ICOM introduced the IC-705 radio, a 10-watt QRP multiband multimode portable capable of operating from all bands from 160m (1.8 MHz) to 70cms (432 MHz) with the exception of the 4m (70 MHz) band.
For a low power radio, the amount of hype and buzz surrounding it has been amazing. There has been a host of online reviews, blog posts and videos about it but they tended really only to concentrate on the radios features rather than its performance.
In addition, I think it's fair to say that a lot of the reviews were done by HF operators. I saw one person doing a frequency stability test on WSPR on 20m (14 MHz) which was frankly useless as it meant nothing. Frequency tests need to be done at the highest operating frequency on the radio i.e. 432 MHz where the changes would be the biggest.
RadCom Review... In the April edition of RadCom magazine, a full review was carried out by Peter Hart, G3SJX. Peter carries out extensive performance tests of radios on his bench on a regular basis and his reviews are highly regarded as they're seen to be truthful and honest. If there is a problem or issue with a radio then he calls it out for people to see.
The review is quite extensive running to five pages but I noted that he mentioned some 'low level intermodulation products' appearing with some 'quite small input signals' on the VHF bands. Whether you'd notice these or not I guess might depend on how RF quiet your location is.
One of the big questions that VHF operators had about this radio was about its frequency stability. The previous IC-9700 was known to drift and many VHF guys had to add third-party GPS locked frequency standards to overcome this. Would the IC-705 have the same issue?
When the IC-705 was introduced, it was mentioned that it had a built in antenna for GPS and some people speculated that the frequency stability might be GPS locked as a result.
Peter confirms in his review that the IC-705 uses a high stability temperature controlled crystal oscillator to achieve a performance of 0.5 parts per million (PPM). The built in GPS is as far as I know just there primarily for D-Star operation in terms of timing and location.
I did however come across a YouTube video today from Hayden, VK7HH who did a frequency test on 432 MHz with WSPR.
While the IC-705 did drift 2Hz over the two minute transmission, it did stay within the required 4Hz window for the mode.
In Conclusion... In his final summary, Peter G3SJX concludes..."The IC-705 is a great take-anywhere QRP radio, ideal for all outdoor activities and SOTA expeditions. Covering HF through to the UHF bands with all-mode operation, a top-level performance and extensive remote connection capabilities, it is quite a remarkable piece of kit. Currently priced at £1300, it is excellent value for money."
It might be outside the price range for some but it looks that it's a great radio for those who can afford it.
RadCom...RadCom is the journal of the Radio Society of Great Britain and is posted out on a monthly basis to all members. A digital version is also available on their website for members to view and each issue stays there for 12-months.
A new report by Michael, G7VJR of the popular ClubLog website shows that an amazing 84% of contacts on the 50 MHz band over the last 13-months have been via the FT8 digital mode.
The data is taken from the almost 1.8 million QSO's logged on the site in the last 13-months.
This is bound to stir some controversy with a lot of people having misgivings about how this digital mode seems to be replacing the traditional SSB and CW means of communication.
As can be seen from this previous post, FT8 has enjoyed an explosion in popularity since it was released in 2017.
It does look though as if the pendulum have swung a bit too far in the digital direction. During the Summer Sporadic-E season, there are many times where signals are reasonably strong and a SSB contact could be completed in a much shorter time frame than say a FT8 contact with its 15-second transmission cycles going back and forth.
There is also the advantage of SSB and CW users being spread out over 100 or so kHz where as the FT8 users are all gathered at the 50.313 MHz watering hole.
How to get more of a balance though might be easier said than done.
The latest stats from the Clublog website suggests that the FT8 digital mode now accounts for over half of all contacts made on the amateur radio bands in the year 2020.
The chart below from July 2017 to March 2021 shows how FT8 has grown to dominate the bands since its release in the second half of 2017.
Surprisingly, the newer and faster FT4 mode doesn't seem to have made any inroads on the popularity of FT8 since its introduction in late 2019.
Tens of thousands of logs are uploaded to the Clublog website every year and the data trends for 2020 are based on over 66.4 million contacts.
Back in the middle of March 2021, I reported in a previous blog post how F0FYF in the east of France had heard a beacon on 144 MHz that was using the same callsign as the ZD7GWM beacon on St Helena in the South Atlantic.
After listening to various recordings, I was able to confirm that the signal heard by F0FYF was different from the real one.
Now, there is a report that the beacon has been heard by someone else in France but on a completely different beam heading.
Someone left a comment on the blog of Jeff, F0FYF to say that they had heard the bogus ZD7 beacon on 144.475 MHz as well! This person said that he was in the south of Perpignan and that the 'beacon' was on a beam heading of 70 degrees from his location. He was using a 7-element Yagi on a 9-metre mast.
F0FYF originally said that he had heard the beacon on a beam heading of 200 degrees. I plotted out these two beam headings and they intersect near Marseilles.
They also said that the beacon is often on air for 90 minutes to 2 hours at a time on a regular basis.
Is it located somewhere inside the circle above?? It would be interesting for some local French radio amateurs to have a listen. Is there an online SDR with 2m in the area?
There was a hint of the upcoming Sporadic-E season when there was a weak opening on 28 MHz on Friday 26th March 2021. It didn't amount to much though and it seemed mainly confined to Spain.
The previous day, the 25th of March was a bit unusual in that I didn't hear a single FT8 signal on 10m all day. I nearly always hear something.
As we move into early April, the Sporadic-E openings on 28 MHz should start up with maybe more regular openings later in the month.
