Sunday, June 14, 2020

First contact between Lithuania and Slovenia made on the new 40 MHz band - 13th June 2020


At the end of April 2020, LY2YR in Lithuania made a contact with EI4GNB in Ireland for the first LY-EI QSO on the new 40 MHz amateur band.

Gintas, LY2YR achieved another first for the 8-metre band when he worked Borut, S50B in Slovenia on the 13th of June 2020 using the FT8, FT4 and CW modes. The frequency used was 40.680 MHz which is in the middle of the ISM (Industrial, Scientific, Medical) band.

Even though the ISM band of 40.660 MHz to 40.700 MHz has been allocated for beacons in Slovenia since 1998, it was only this year that the licencing authority there clarified that radio amateurs could make contacts as well.

The contact between LY2YR and S50B was approximately 1270 kms and the propagation mode was Sporadic-E. Even though the distance is pretty normal for Sporadic-E, there were some difficulties due to some 1000-metre high mountains just a few kms from S50B's location. Both stations had to wait until the Sporadic-E was strong enough to overcome the path loss.

LY2YR also completed an FT8 contact with S50TG, the 17-year old son of S50B.


For the first Lithuania to Slovenia 8-metre contact, LY2YR was using a YAESU FT-200 and a Hexbeam for 28 MHz/50 MHz.

S50B was using an ICOM IC-7100 with about 100 watts into a SIRIO vertical for 8-metres.


S50B is now looking to make the first 40 MHz contact with Ireland.

Links...
1) For more information on the new 8-metre band, see the 40 MHz page... https://ei7gl.blogspot.com/p/40-mhz.html

Wednesday, June 10, 2020

WSPR balloon on 20m over the Arctic - 10th June 2020

On the morning of the 10th of June, I left the radio monitoring the WSPR frequency on 20m to see if I would hear anything special. I noted two signals...


Australia... The first was the signal from VK3MO and VK3QN in Australia, always interesting because of the distance. I'm not 100% sure though if they were short path as shown on the map or long path. Might be something worth checking another time.

The one that really caught my eye was the VE3KCL callsign with the strange locator. I assumed at first a decoding error but no, it turns out to be a very small WSPR transmitter hung underneath a helium balloon over the Arctic Ocean!

As of the evening of the 10th of June, it was at an altitude of 10,000 metres, in constant sunlight, has a temperature of minus 6 deg C and is travelling at 18 knots.

It sends out a WSPR signals on 20m with a power output of 10 milliwatts. It was launched on the 16th of May 2020 and has is now starting its third circumnavigation of the planet.

More info here... http://qrp-labs.com/flights/u4b9.html

There are some of the WSPR decodes that I got which shows the locator square changing...

Timestamp Call MHz SNR Drift Grid Pwr Reporter RGrid km az
 2020-06-10 20:58  VE3KCL  14.097177  -30  0 MR20 0.01 EI7GL IO51tu  4047 266 
 2020-06-10 20:38  VE3KCL  14.097178  -29  0 MR10 0.01 EI7GL IO51tu  4011 264 
 2020-06-10 19:48  VE3KCL  14.097178  -25  0 MR11 0.01 EI7GL IO51tu  4024 262 
 2020-06-10 18:38  VE3KCL  14.097184  -25  0 MR01 0.01 EI7GL IO51tu  3992 260

In addition to the QSPR signal, it is also sending out a QRSS signal in the form of a balloon!

The image I got a grab of isn't great but you can make out the circle in the waterfall.



Summer 2020 edition of ECHO IRELAND now available for IRTS members to download


The PDF version of the Summer 2020 edition of ECHO IRELAND, the IRTS newsletter is now available for members to download... www.irts.ie/echo/download.html

Tuesday, June 9, 2020

Illegal Fishing Buoy on the 28 MHz WSPR Frequency

Back in June of 2018, I had a post up about how I had noticed an illegal fishing buoy on the FT8 frequency of 28.074 MHz. Today, I noticed one on the WSPR frequency of 28.1246 MHz.


Truth be told, these things are all over the bottom of the 10-metre band and it's not hard to stumble across them.

The image above shows the fishing buoy on the waterfall display of the WSJT-X programme. It turns on as a carrier which rapidly drifts upwards, settles down and finally gives an ID in morse. The whole transmission lasts for about 10 seconds.

I was listening one day on 28.200 MHz for the International Beacon Project cluster of beacons and sure enough, there was one there as well.

From what I understand, they are used to mark the position of fishing nets at sea and are almost impossible to police or regulate.

Monday, June 8, 2020

Trans-Atlantic opening on 28 MHz - Sun 7th June 2020


There was a nice trans-Atlantic opening on 28 MHz and 50 MHz late on Sunday the 7th of June 2020. I had no real interest in trying to make any contacts so I left the radio monitoring the WSPR frequency on 28.1246 MHz.

WSPR signals heard...

Timestamp Call MHz SNR Drift Grid Pwr Reporter RGrid km
 2020-06-07 23:40 W8AC 28.126032  -24  0 EN91jm  5  EI7GL IO51tu  5434
 2020-06-07 23:28 W8AC 28.126032  -26  0  EN91jm  5  EI7GL IO51tu  5434
 2020-06-07 23:24 W8EDU  28.126102  -26  0  EN91fm  5  EI7GL IO51tu  5455
 2020-06-07 23:12 W8EDU  28.126102  -23  0  EN91fm  5  EI7GL IO51tu  5455
 2020-06-07 23:10 W8AC 28.126032  -25  0  EN91jm  5  EI7GL IO51tu  5434
 2020-06-07 23:04 W8EDU  28.126102  -26  0  EN91fm  5  EI7GL IO51tu  5455
 2020-06-07 22:58 WA9WTK  28.126062 -23  0  FN42fk  10  EI7GL  IO51tu  4734
 2020-06-07 22:58 WB8ILI  28.126083 -25  -1 EN82pq  5 EI7GL IO51tu  5451
 2020-06-07 22:56 W8EDU  28.126102  -22  0  EN91fm  5  EI7GL IO51tu  5455
 2020-06-07 22:18 WA3DNM  28.126074 -18  0  FM29fw  5  EI7GL  IO51tu  5168
 2020-06-07 22:10 VE1VDM  28.126125 -26  0  FN85ij  2 EI7GL IO51tu  4001
 2020-06-07 22:00 VE1VDM  28.126125 -23  0  FN85ij  2 EI7GL IO51tu  4001
 2020-06-07 21:58 WA9WTK  28.126063 -22  0  FN42fk  10  EI7GL  IO51tu  4734
 2020-06-07 21:50 VE1VDM  28.126125 -21  -1 FN85ij  2 EI7GL IO51tu  4001
 2020-06-07 21:40 WA3DNM  28.126075 -17  0  FM29fw  5  EI7GL  IO51tu  5168
 2020-06-07 21:40 VE1VDM  28.126124 -23  0  FN85ij  2 EI7GL IO51tu  4001
 2020-06-07 21:38 WA3DNM  28.126075 -15  0  FM29fw  5  EI7GL  IO51tu  5168
 2020-06-07 21:30 VE1VDM  28.126124 -22  -1 FN85ij  2 EI7GL IO51tu  4001

VE1VDM was the first signal heard at 21:30 UTC and the last trans-Atlantic signal was from W8AC in Ohio at 23:40 UTC.

Most of the stations were running 4, 5 or 10 watts. The strongest SNR (Signal to Noise ratio) was -15dB which would have meant that it was buried in the noise and barely perceptible by ear.

I suspect the signals from VE1VDM may have been double hop Sporadic-E while the US stations were triple hop.

QRSS... Most the QRSS (very slow morse) transmissions from North America are just below the WSPR frequency. This allow you to look at the WSPR waterfall display in WSJT-X and see if there are any QRSS signals there.

As soon as I heard VE1VDM in Nova Scotia on WSPR, I opened up the SpectrumLab programme to take this screen grab...


In the graphic above, the vertical dotted lines mark 5 minutes of time so the scan from left to right took about 20 minutes. You wouldn't want to be in a rush to go anywhere with QRSS šŸ˜Š

The signal from VE1VDM was actually stronger before this grab was taken so I would guess the QRSS signal is equivalent to roughly a -22dB WSPR signal. This seems to be about the limit of where a QRSS signal can be seen properly.

The really interesting signal though is the 100 milliawatt one. If you know the QRSS callsign in advance, you can infer the relevant information from the fragments on the screen even when the signal is much lower.

As an aside, I did see a very weak sawtooth waveform as ell during the opening.

I'm assuming for now that it was just some sort of local interference but I took a screenshot of it just for reference.

Low Band VHF... After seeing a report on Twitter about US fire traffic on 33 MHz, I had a quick look and I did come across a weak unidentified signal on 33.900 MHz. I think I was too late though and the band was closing at that stage.

Saturday, June 6, 2020

69 MHz licence free radio band in Sweden and Finland


I'm always interested to hear about other users of the low VHF bands and it was brought to my attention recently that there was a licence free band at 69 MHz in Sweden.

I had forgotten about this band and when I listened during a recent Sporadic-E opening, I could hear a conversation in Swedish on the calling frequency of 69.1875 MHz.

I thought I'd put together a post to keep a record of the frequencies in use...

Sweden... It seems as if this band which was introduced in 2016 is intended for use by anyone with a need for two way communications without the need of getting a licence. i.e. hunters, forestry workers, farmers, etc or just people who want to communicate like on CB.

There are 8 channels at the bottom of 69 MHz with a power limit of 25 watts. These are in 12.5 kHz steps...

CH1 - 69.0125 MHz
CH2 - 69.0375 MHz
CH3 - 69.0625 MHz
CH4 - 69.0875 MHz
CH5 - 69.1125 MHz
CH6 - 69.1375 MHz
CH7 - 69.1625 MHz
CH8 - 69.1875 MHz Calling Channel

There are another 10 channels further up the band. These have no channel numbers, have a maximum output power of 5 watts and have channel steps of 6.25 MHz.

69.60625 MHz
69.61875 MHz
69.63125 MHz
69.64375 MHz
69.65625 MHz
69.66875 MHz
69.68125 MHz
69.69375 MHz
69.70625 MHz
69.71875 MHz

* * * * *

Finland... Finland has a similar system called RHA68 with channels in the 68 MHz to 72 MHz range.

Channel group A

Channel Frequency Usage Power limit
1 68.100 MHz Roadside assistance organizations 25 W
2 68.300 MHz Motor sports 25 W
3 68.425 MHz Voluntary rescue service 25 W
4 68.525 MHz Motor sports 25 W
17 68.225 MHz Voluntary rescue service 25 W

Channel group E

Channel Frequency Usage Power limit
5 68.050 MHz General use 5 W
6 68.575 MHz General use 5 W
7 68.175 MHz General use 5 W
8 67.500 MHz General use 5 W
9 71.375 MHz General use 5 W
10 71.425 MHz General use 5 W
11 71.475 MHz General use 5 W
12 71.625 MHz General use 5 W
13 70.200 MHz General use 5 W
14 71.025 MHz General use 5 W
15 71.050 MHz General use 25 W
16 71.100 MHz General use 25 W
18 68.375 MHz General use 25 W
19 71.175 MHz General use 25 W
20 71.750 MHz General use 25 W
21 71.900 MHz General use 25 W
22 71.350 MHz General use 5 W
23 71.550 MHz General use 5 W
24 71.575 MHz General use 5 W
25 71.600 MHz General use 5 W
26 72.325 MHz General use 5 W

Links...
1) Swedish 69 MHz Facebook Group (Private Facebook Group - Need to join to see posts)

Friday, June 5, 2020

Radio experiments for the Solar Eclipse on the 21st of June 2020


There is annular solar eclipse coming up on Sunday the 21st of June 2020 and the track is shown above. An annual eclipse is where the moon blocks most but not all of the light from the sun and in the centre of the path, the eclipse looks like a ring of fire.

Even though it's not a total eclipse, most of the radiation from the sun will be blocked and a group of scientists are looking for volunteers to monitor a Chinese time beacon on 10.000 MHz for any changes.

This citizen science project involves monitoring the time standard for extended periods of time using the FLDIGI software.

More info here... https://hamsci.org/june-2020-eclipse-festival-frequency-measurement

The eclipse also raises the possibility of individuals doing their own experiments. Is it possible to monitor say WSPR signals that cross the path or maybe monitoring the signal strength of a broadcast station?

It would probably involve doing some tests either side of the solar eclipse to make sure that the effects you saw were actually due to the eclipse.

The eclipse starts around 04:30 UTC and ends around 08:30 UTC. The maximum point will be over the north of India around 06:30 UTC.

Link...
1) Wikipedia link for the 2020 Solar Eclipse

Addendum...

Thursday, June 4, 2020

Video about the VK9XG expedition to Christmas Island in 2018

In October of 2018, six radio amateurs from the UK activated Christmas Island which is to the south of Indonesia in the Indian Ocean. A presentation on the expedition was given at the RSGB convention in 2019 and the RSGB have now just put it up on YouTube.



I have to admit that I have pretty much no interest in these type of expeditions but I found a few points of interest in the video.


As you can see from the map below, Christmas Island is located to the south of Indonesia.


This meant that while it was easy to work areas like Japan, it was more difficult to work Europe and North America.

As you can see from the image below, they were located next to the Indian Ocean, an ideal spot for radio.

Back in October of 2018, the Solar Flux would have been very low as we were well on the way to the bottom of the sunspot cycle. This essentially meant that the higher HF bands like 10m & 12m were very poor and most of the contacts were on 21 MHz and below.


A breakdown of the modes is... SSB 11.5%, CW 68% and FT8 20.5%. This suggests that for the SSB only operator then it was going to be hard to make a contact with them.

It also reflects the explosion of interest in what was then the new FT8 digital mode and the decline in modes like RTTY.

The use of FT allowed allowed an analysis of received signal strengths.


Those with a signal to noise ratio of 0dB and above would have supported a SSB contact.
Contacts on CW would have been possible at -12dB and above.
Those contacts below -12dB were only possible on FT8.

This reflects the poor conditions and shows again that it was tough going for the SSB only operator to catch them.

It also reflects why weak signal modes like FT8 have had such an impact as it allows those with modest stations to compete with the rest.

160 Metres... It was interesting to see how they were able to work stations in the USA and how the pattern followed the areas just before sunrise.

On a more disturbing note, there were also stations on the east coast of the USA renting out time on a remote station on the west coast to make a contact on top band.

Technically it's within the rules of the ARRL DXCC programme. Morally, it's just cheating.


Links...
1) Info on ClubLog

Moonbounce on 21 MHz from the worlds largest antenna array for the band!

The 21 MHz antenna array of ES5RY in Estonia is reputed to be the largest in the world for that band.


The array is made up of eight 5-element Yagi's for 15m mounted on a 70-metre tower. It has a gain of 16dBd in free space with a beamwidth of less than 30 degrees.

It has a phasing system which allows the selection of five different take-off angles.... 4, 7, 10, 15 and 30 degrees.

Here is a video of ES5RY hearing a signal coming back from the moon on 21 MHz!



This next video shows the construction of the array...

Wednesday, June 3, 2020

Amazing 5600 km opening on 144 MHz from Cape Verde Islands to Poland

This post is now in two parts.

The original post is shown in Part 1 below.

The updated information with the log from D4VHF is shown in Part 2 further down the post.

* * * * *

Part 1...


On Friday the 29th of May 2020, there was an extensive Sporadic-E opening across Europe which reached as high as 144 MHz allowing stations across the continent to make many fine contacts.

The most extraordinary contacts however was probably the opening from the Cape Verde Islands off the coast of Africa to Poland on 144 MHz. The longest path recorded seems to have been when the FT8 signals from D4VHF were heard by SP5XMU in Warsaw, a distance of just over 5,600kms.


The map above shows the stations on FT8 that reported hearing or were heard by D4VHF. The most intensive part of the Sporadic-E seems to have been along a narrow corridor stretching from Lyon in France to Warsaw in Poland.

Mode of Propagation... It seems very likely that there were two propagation modes at work for this extraordinary path from the Cape Verde Islands to Central Europe.


As shown by the tropo prediction map above courtesy of F5LEN, there is a reasonably stable maritime tropo duct from the Cape Verde Islands to south coast of Portugal, a distance of about 2,800kms.

The path from Poland to the south-west of the Iberian Peninsula was spanned by a Sporadic-E opening which was in progress across Europe at the time.

As with openings of this nature, there is always the possibility of double hop Sporadic-E which can't be discounted for a good part of the path. However, this tropo duct off the north-west coast of Africa is a remarkably steady feature and it seems to be there for a large part of the year. It's hard to imagine that it didn't play a major part in the opening.

FT8 screenshot from D4VHF

In 2019, there were other similar mixed Sporadic-E & tropo duct openings from Cape Verde to Italy and Germany. The distances involved with this opening to Poland though are exceptional.

* * * * *

PART 2...

Update. Now that the dust has settled, we can look at the log of D4VHF and who they worked...


While many stations heard D4VHF on FT8, a much smaller number managed to make a contact.

Here is the log...

2020-05-29,10:05:15, CT1END,IM58,144.175900,FT8,-07,-04,,,
2020-05-29,11:10:00, IK4ADE,JN54,144.175900,FT8,-07,-09,,,
2020-05-29,11:57:15, IK0ZYH,JN62,144.175900,FT8,-15,-17,,,
2020-05-29,12:15:45, EA8AJC,IL18,144.175900,FT8,+28,+17,,,
2020-05-29,12:36:00, F6EAS,,144.175900,FT8,+04,+02,,,
2020-05-29,12:43:30, EC1KV,,144.175900,FT8,-15,-15,,,
2020-05-29,12:49:15, F1DUZ,IN97,144.175900,FT8,-18,-19,,,
2020-05-29,12:52:00, F6CIS,,144.175900,FT8,-15,-19,,,
2020-05-29,12:59:45, F6DBI,IN88,144.175900,FT8,-03,-07,,,
2020-05-29,13:22:30, F8DBF,IN78,144.175900,FT8,-06,-08,,,
2020-05-29,13:47:00, G4RRA,,144.175900,FT8,-15,-16,,,
2020-05-29,13:49:00, G8BCG,,144.175900,FT8,+00,-16,,,
2020-05-29,13:52:00, GW7SMV,,144.175900,FT8,-05,-16,,,
2020-05-29,13:54:30, G3NJV,IO70,144.175900,FT8,-15,-01,,,
2020-05-29,13:55:30, G7RAU,IN79,144.175900,FT8,-13,-13,,,
2020-05-29,14:19:15, CT1IUA,IM67,144.175900,FT8,-16,-12,,,
2020-05-29,15:27:00, DJ8RZ,JN58,144.175900,FT8,-08,-10,,,
2020-05-29,15:30:45, DL5MCG,,144.175900,FT8,-09,-19,,,
2020-05-29,15:34:45, I2FAK,JN45,144.175900,FT8,+10,-11,,,
2020-05-29,18:41:15, CT1ANO,IN51,144.175900,FT8,-18,-19,,,
2020-05-29,18:55:15, CU2GI,HM77,144.175900,FT8,-19,-18,,,
2020-05-30,08:39:45, EA8AIN,IL18,144.175900,FT8,-09,+08,,,
2020-05-30,16:21:30, EA7FDW,IM76,144.175900,FT8,-11,-12,,,
2020-05-30,16:44:45, EA7E,IM66,144.175900,FT8,-18,-20,,,
2020-05-30,16:49:45, CT1EYQ,IM58,144.175900,FT8,-18,-17,,,
2020-05-30,17:16:45, EC2AGL,IN91,144.175900,FT8,-06,-16,,,
2020-05-30,17:22:45, CT1ADT,IM57,144.175900,FT8,-13,-07,,,

The FT8 signals sent and received by D4VHF according to the PSK Reporter website are shown at the end of this post.

Some points...

1) SSB V FT8... For a Sporadic-E opening on 144 MHz, a mode like SSB would be much better in terms of speed. However, look at the signal strengths in the log. Most are in the minus dB range so a SSB QSO would probably have not been possible.

As for what would be a better mode is up for debate. Marginal contacts via CW? Faster digital modes like FT4? No matter what mode was used, there would have always been incomplete contacts and a limit to how many would get in the log.

2) Mode of Propagation... From what we know, there seems to be two components.

First, there is a marine duct off the west coast of Morocco which allows VHF signals to propagate from Cape Verde Islands up to the Canary Islands (1500kms), Portugal & Spain (3000kms) and the UK (4000kms).

According to one of the operators of D4VHF...Mark EA8FF, there was no tropo between D4 and EA8 or EA7 at the time. And yet, this marine duct over the sea was probably present for a good part of the path. I don't think we can discount it and yet, there must surely be Sporadic-E openings on 144 MHz in that part of the world as well? We can't always assume it's a marine duct.

While we can debate the paths from D4 to the coasts of Portugal or the south of Spain, those signals from further north were almost certainly via Sporadic-E.

The question is was it tropo & Sp-E, multi-hop Sp-E at 144 MHz?? Just in terms of probability, I personally don't believe in triple hop Sporadic-E at 144 MHz. Double maybe, triple?!?!

3) Sporadic-E to the UK... The problem with just a list of stations is that there are like data points for a graph, they don't make much sense until you draw the graph. In the same vein, when you generate a map and see the location of the stations, you can see patterns.

Again, see the map above. Note how the UK stations are strung out in a nice narrow line. This is a classic Sporadic-E footprint. The furthest station was GW7SMV at just over 4300kms.

4) Poland... The other unusual dimension to this opening was the unusual opening at the same time from Portugal to Poland. See the QSO map below from Tom, SP5MXU...


As you can see, SP5XMU was able to work stations in Portugal at a distance of almost 2800kms. What is unusual about this is that the usual maximum distance for one-hop Sporadic-E is about 2300kms. Where did the extra 500kms come from?

This is usually explained by say a tropo extension at one or both ends. Another is the possibility of chordal hop as suggested by SO3Z in the comments. In that scenario, the signal is going between two Sporadic-E clouds before returning to the ground again.

The chordal hop theory may help explain how the 144 MHz signals covered at least part of the 5600km distance from Cape Verde Islands to Poland.

Part 2 Conclusion... In the past with traditional modes like SSB and CW, we could be reasonably sure about the mode of propagation on VHF bands like 2 metres. Now with digital modes like FT8 we are seeing signals buried in the noise which makes it harder to be certain about how the signal was propagated.

I know FT8 isn't popular with everyone but the new digital modes are allowing radio amateurs to discover paths on VHF that we never knew existed.

* * * * *

Equivalent Distances... As always, it's interesting to look at some maps to put these remarkable distances in perspective.


The 5600 km distance from the Cape Verde Islands to Warsaw would reach as far north as Oslo, the capital of Norway.

It's hard to believe but the whole island of Iceland is actually closer!

From a western perspective, the equivalent distance reaches as far as Washington DC in the USA.


Remember, there are no satellites or moonbounce involved here. This is a 144 MHz signal being propagated by Sporadic-E and tropo.

What if...??? The map of the USA above suggests maybe one potential extraordinary path. From time to time, there seems to be a tropo duct across the Atlantic from Care Verde to the the Caribbean. Could this be extended even further to the west by a Sporadic-E opening at the same time???

FT8 signals heard by D4VHF...(over 3400kms)

Monday, June 1, 2020

QRSS reception reports on 28 MHz - Fri 29th May 2020

Friday the 29th of May 2020 was an extraordinary day with widespread Sporadic-E across Europe. While the various VHF bands up to 144 MHz were open, I spent some time listening for QRSS signals (very slow visual morse code) on 28 MHz.

To put the European stations heard in context, first see the map with distances below...


a) First Grab... The short skip on 28 MHz started early and I heard the usual stations near London, roughly 650kms.


M0BMN is a lot further west and as he is just 430kms away, I had trouble getting a good trace of his QRSS signal.

b) Doppler... This is another screen grab later on. Note the double trace on some of the signals.


Pay special note to the signal from G0FTD. On the left, it's weak but clear. On the right, there are two distinct signals from him. The upper trace is steady and is almost as if that signal is coming from a stationary Sporadic-E cloud. The lower trace starts to diverge more over time as if it that signal was coming from something moving at speed and creating doppler shift.

I suspect it was coming from a Sporadic-E cloud that was in motion and half-ways through the second trace, it either reached a point or ionization level that it no longer supported propagation.

The other theory might be that it was aircraft scatter although I still prefer the moving Sp-E cloud theory.

c) Iceland... There was also some good Sporadic-E conditions to the north and I got a screen grab from TF3HZ in Iceland for the first. time.


I also noted a signal up higher in the band but I'm unsure who it is? The amount of Frequency Shift Keying (FSK) seems to be lower than the rest.

(Update: The mystery signal is LB3AH in Oslo, Norway).

d) TF3HZ & M0GBZ clashing... In this screen grab, note the signal from TF3HZ. At first, he is in the clear and on his own. Then the short skip to the east improves and I note that TF3HZ in Iceland and M0GBZ near London are actually on the same frequency.


On a band where there are just 10 or so Hertz between stations, it's easy to end up on the same frequency as someone else especially if they are from a different area.

(Update: The mystery signal at the top is probably an image of G0FTD. The mystery signal at 620 Hz is LB3AH in Norway)

As this second grab shows, they were clashing for quite a while as the conditions were excellent.


e) M0GBZ in the clear again... In this grab, you can see how on the left, TF3HZ in Iceland and M0GBZ to the north of London are still clashing. I then lose the path to Iceland and the signal from M0GBZ becomes clear again.


f) Trans-Atlantic... VE1VDM... All of the QRSS signals from Europe are via one-hop Sporadic-E. To cross the Atlantic, the signal needs several Sporadic-E hops.

As I'm on the north-west edge of Europe, I'm within two Sporadic-E hops of Vernon, VE1VDM in Nova Scotia in Canada.


I first noticed VE1VDM's signal on WSPR on 28.1246 MHz and he transmits a QRSS signal as well just below it. He sends the letters VDM and the weak signal is shown below...


Vernon also transmits a QRSS signal on 28.0008 MHz where the European stations are...


And that mysterious signal again?!?

During another grab, there was a brief opening to G6NHU near London and I could see that VE1VDM was almost on the same frequency.


Towards the bottom of the screen, there is a very faint record of the signal from OK1FCX in the Czech Republic. He sends a signal that has three levels so it can be easy to identify even if the signal is too weak to decode.

In conclusion... Another good day for QRSS signals on 28 MHz and it's interesting to note the way signals change over time. As noted in a previous post, I believe QRSS is the only mode where you can actually see the propagation changing visually.

At this stage, I'm running out of new stations to catch! I think I have seen most of the European stations at this stage.

Links...
1) Report from MW1CFN for 28 MHz QRSS signals heard in NW Wales on the same day.

Friday, May 29, 2020

WSPR problems at 28 MHz...


WSPR - Weak Signal Propagation Reporter. I have been monitoring the WSPR frequency on 28 MHz recently as the conditions have been really good and there are now a good number of stations mostly from the northern half of Europe transmitting on the band.

There are a few important issues that you must be aware of when you transmit a signal on WSPR.

1. Timing... Regardless of the band, your time on your PC must be spot on. I've seen examples where people are transmitting tens of seconds too late!  This is an example of people just letting their WSPR transmitters on without checking if it is working ok.

WSPR transmission outside the two minute window marked by the Green lines

2. Frequency... On the lower bands like say 80m or 40m, transmitters drift a lot less. On 10m, the frequency accuracy and drift becomes a bigger issue.

This is an example from the WSJT-X waterfall of someone way off frequency....


This WSPR frequency on 10 metres is 28.1246 MHz and the band is just 200 Hz wide i.e. audio frequencies of 1400 to 1600 Hz.

As you can see from the screenshot above, someone was about 230 Hz too low and no-one is ever going to decode them.

3) Drift... For the two minute WSPR transmission, the signal shouldn't drift by more than 4 Hz.


This image above shows the frequency of the WSPR signals plotted against time. The signals in the top half of the image show normal WSPR signals which are two minutes in duration. As can be seen, they are nice and straight.

In the lower part of the image, there is an example of a drifting WSPR signal. Over the two minutes, it drifts in the region of 15 Hz, way too much to be ever decoded.

If you're on WSPR on 28 MHz and you're not being heard then look at your time, frequency and drift.

Thursday, May 28, 2020

Digital radio for the Marine VHF Band???

I find it interesting to follow how digital radio is gradually replacing its analogue counterparts.

The Electronics Communications Committee (ECC) of CEPT recently released an article outlining how digital radio could be introduced to the Marine VHF bands.

At present, the allocated frequencies are in the frequency band 156.025 MHz to 162.025 MHz and are mostly FM i.e. analogue.

The channel spacing is 25 kHz which means that there is a lot of spectrum on the band not being used and there is the potential to squeeze a lot more channels in.

In the article, it states that "with the exception of the automatic identification system (AIS) on channels AIS1 (161.975 MHz) and AIS2 (162.025 MHz) and digital selective calling (DSC), currently all the remaining listed channels are used for analogue voice communication. With the digital data exchange allocations in future, some channels will be used for data transfer and not for voice communication any longer. New digital radios need to be developed, which is different equipment than the current voice communication radios. As the result, the frequencies in the VHF maritime mobile band will be shared by four different systems: analogue voice telephony, DSC, AIS and digital data exchange."

There is a huge legacy issue though to overcome first. For a business, they can just swap out the gear and radios when they upgrade from FM to digital. With the Marine VHF band, there is a huge decentralised user base that will take years to change over.

The article suggests the use of DMR (dPMR) as introduced in recent years on the amateur bands..."The technical candidate solution is dPMR (digital Private Mobile Radio) – a technology currently used in land mobile communications as a replacement for analogue FM voice communication in both VHF and UHF bands. dPMR has been standardised by ETSI, the European standards organisation."

The article suggests that initially, the new digital channels which take up 6.25 KHz and these would fit between the existing analogue FM channels as shown below on the left.
Eventually the FM channels would be phased out and be replaced with all digital (above right). The end result would be a doubling of the number of channels on the Marine band.

It not hard to imagine perhaps a transition period where dual mode (FM & DMR) radios would exist and then there would have to be a date whereby everyone would need to changed over to digital.

In tests done in Estonia, they reported..."Participants in the test were generally positive about the introduction of digital communication with the range being the same (or better) than the range for analogue communication. At the maximum distances, the digital communication remained understandable (d = 19,6 NM) while the analogue communication experienced very high noise and was not understandable."

In the tests done in the Netherlands, they reported..."The users and the observers found the digital voice quality the same or better than the analogue one. The users reported back that listening to digital voice with noise reduction made it easier and less intensive to listen. The users concluded that the digital transmission of voice enabled the same functionality of operation of the ship as for an analogue radio system."

Full article... http://apps.cept.org/eccnews/may-2020/index.html

Monday, May 25, 2020

First trans-Atlantic QRSS signal of 2020 on 28 MHz - Mon 25th May 2020


Monday 25th May 2020. For a change, I left the radio on the WSPR frequency of 28.1246 MHz this morning to see what could I hear. At the time, there seemed to be some unusual propagation in that I was hearing Iceland to the north-west.

Then I got two decodes of the WSPR signal from Vernon, VE1VDM in Nova Scotia, Canada!

Timestamp          Call MHz SNR Drift Grid Pwr Reporter RGrid km az
 2020-05-25 11:30 VE1VDM 28.126118  -24 -2 FN85ij 2 EI7GL  IO51tu  4001 59 
 2020-05-25 11:20 VE1VDM 28.126118 -22 -1 FN85ij EI7GL  IO51tu 4001 59 

While 28.0008 MHz is the usual QRSS frequency on 10 metres, some stations transmit right next to the WSPR frequency of 28.1246 MHz so that receive stations can listen for both WSPR and QRSS signals without changing frequency.

It just so happened that I had the SpectrumLab audio analyzer programme running as I often use it to check the frequency of beacons on 28 MHz. When I looked, I could see the QRSS signal (very slow morse) from VE1VDM but it was slightly drawn out as I was using the 'QRSS 1' option. I switched to QRSS 3 and the screen grab is shown above.

I suspect the signal from Vernon may have been at its best when I was hearing the WSPR signals. I'd guess that the QRSS signal used to generate the plot shown above is certainly not stronger than the -22dB or -24dB WSPR signal.

VE1VDM was using a QRP Labs U3S and 5 watt PA combo sending 4 watts into a full size Windom hung as an inverted V at about 30' AGL at apex, I was using a vertical half-wave for 28 MHz about 4 metres above ground level.

Mode of Propagation???... How did this QRSS signal cross the North Atlantic?


A few days ago, VE1VDM had been heard on WSPR in Luxembourg and Germany, a distance of about 5000 kms. This was most probably triple hop Sporadic-E... i.e. 1700kms x 3 hops. The second hop signal that day was probably landing somewhere in the ocean about 600kms to the west of Ireland.

For the trans-Atlantic opening today, I think I was hearing VE1VDM via double hop Sporadic-E i.e. 2 x 2000km hops. It's likely that the signal may have reached only Ireland and the western part of the UK as that's close to the limit for two hops on 28 MHz.

For more information on QRSS activities, there is an active group HERE

4000km+ path from the UK to Cape Verde opens up on 144 MHz - May 2020


Monday 25th May 2020. It looks as if the maritime tropo duct from the UK to Cape Verde Islands off the west coast of Africa is open again.

The 144 MHz reports are shown below...

Wednesday 27th May 2020...
It looks as if the path to the UK may have been disrupted but it looks as if there was a Sporadic-E opening allowing stations in France and the N of Spain to access the marine duct to the west of Morocco.



Tuesday 26th May 2020...
D4VHF G4LOH 2m FT8 4098 km 08:47:14
M0AFJ D4VHF 2m FT8 4094 km 07:41:26
D4VHF G3NJV 2m FT8 4090 km 01:03:14
D4VHF G7RAU 2m FT8 4086 km 08:24:14
D4VHF GW4SHF 2m FT8 4404 km 01:00:14
D4VHF EI3KD 2m FT8 4170 km 00:24:14

Monday 25th May 2020...
Txmtr Rcvr Band Mode Distance Time (UTC)
GW4VXE D4VHF 2m FT8 4280 km 16:25:27
D4VHF GW0KZG 2m FT8 4276 km 20:56:11
D4VHF GW1JFV 2m FT8 4264 km 22:34:41
D4VHF EI8IQ 2m FT8 4256 km 19:50:14
D4VHF GW6TEO 2m FT8 4249 km 14:44:14
D4VHF EI8KN 2m FT8 4230 km 15:01:11
G0FUV D4VHF 2m FT8 4209 km 20:47:57
MW1CFN D4VHF 2m FT8 4438 km 17:35:56
GB5VEP D4VHF 2m FT8 4438 km 15:21:56
D4VHF G4ELI 2m FT8 4101 km 15:54:14
D4VHF G4LOH 2m FT8 4098 km 07:19:14
D4VHF G3NJV 2m FT8 4090 km 07:18:14
M0AFJ D4VHF 2m FT8 4094 km 07:13:56
D4VHF G7RAU 2m FT8 4086 km 07:09:14
D4VHF GW4SHF 2m FT8 4404 km 04:55:14
G4LOH D4VHF 2m FT8 4098 km 00:01:27

Sun 24th May 2020...
G7RAU D4VHF 2m FT8 4086 km 23:35:26

As you can see, the distances involved are in excess of 4,000kms which is always incredible  when you consider that it's 144 MHz.

The tropo forecast is for a reasonably stable path from Cape Verde up to the Bay of Biscay but the last few hundred kms may be a problem.

Check out the website of Pascal F5LEN for the tropo forecast.... http://tropo.f5len.org/atlantic-ocean/atlantic-d4-ei/

Sunday, May 24, 2020

Trans-Atlantic opening to the USA on 28 MHz - Sat 23rd May 2020


Saturday 23rd May 2020. The 28 MHz band was pretty much open all day with strong signals from all over Europe. I noticed some trans-Atlantic signals late in the evening so I left the radio monitoring the FT8 frequency overnight.

This was the first real multi-hop opening to the USA so far in 2020. The distances in the USA were from 4380 kms to 6370 kms so  think this was probably 3 hop Sporadic-E.

At this time of year, I use FT8 pretty much as a propagation tool. I listen for a while to upload reports to the PSKReporter website and I then check who I have heard in the last 15 minutes. If things get unusual then I start tuning around.

WSPR... When I noticed the FT8 signals were getting very strong, I left the radio on the WSPR frequency. As you can see from the map, there was plenty of short skip on the band in the range of 500 to 1000 kms. i.e. UK, Belgium, N France and the Netherlands.


What I find interesting about WSPR are those signals from stations running less than 100 milliwatts...

Timestamp Call MHz SNR Drift Grid Pwr Reporter RGrid km az # Spots
2020-05-23 17:14 G4KPX 28.126027 -17 0 JO02dj 0.005 EI7GL IO51tu 594 268 1 decode
2020-05-23 17:06 DL0PBS 28.125990 -8  0 JO33 0.05 EI7GL IO51tu 1048 266
2020-05-23 16:36 F4HON 28.126005 -20 0 JN19ij 0.01 EI7GL IO51tu 827 294 2 decodes
2020-05-23 16:26 PD0KT 28.126030 -15 0 JO33le 0.01 EI7GL IO51tu 1046 268  12 decodes
2020-05-23 16:16 ON4LUK 28.126192 -20 -1 JO11 0.05 EI7GL IO51tu 782 277
2020-05-23 15:30 DF4PV 28.126078 -18 -1 JN49ax 0.05 EI7GL IO51tu 1167 287 17 
2020-05-23 12:58 LA1G 28.126045 -21 0 JO49ub 0.02 EI7GL IO51tu 1387 243
2020-05-23 12:56 OZ1IPH 28.126089 -8 0 JO47xi 0.02 EI7GL IO51tu 1324 250
2020-05-23 12:56 OZ2M 28.125996 -15 0 JO65fr 0.02 EI7GL IO51tu 1428 261

As you can see from the edited heard list above, two were running as little as 10 milliwatts and G4KPX has just 5 milliwatts!

QRSS... I had a listen for some QRSS signals from the UK when I was getting started hearing WSPR signals from there...


As outlined in a previous post, most of the UK stations are around London which is about 700kms from here.

The mystery signal 'CDJ' turned out to be Patrick ON4CDJ in Belgium, a distance of about 900 kms. It should be easy to get a proper decode in the future.

I also noticed hints of a very wavy QRSS signal above G0FTD. I think it's probably M0BMN in the west of England. As he is in IO82WN at a distance of about 430 kms, it is very short for Sporadic-E on 28 MHz and will probably take an exceptional opening to get a good signal.