Earth passes through stream of sodium atoms from the Moon once a month

 

There was an interesting article recently in the New York Times about how the Moon has a stream of sodium atoms coming off it and the Earth passes through it once a month. This 'tail' stretching 500,000 kms behind the moon comes from meteorites hitting the lunar surface.

I began to wonder if this would have any impact on Sporadic-E formation? I presume it doesn't as the tail is extremely diffuse and I think it's the dust from metallic meteors coming into the Earth's atmosphere that is the fuel for Sporadic-E propagation.

If however anyone found a weak correlation between Sporadic-E and the times of the new Moon, I would think this source would have to be reconsidered.

Addendum: This is the summary of an article which appeared in Nature in 1972...

THE radio reflexions from the sporadic E region (Es) of the ionosphere show unique properties within a narrow range of latitudes over the magnetic equator. Matsushita1 pointed out that the latitudinal variations of the maximum frequency reflected from the Es region and the solar daily range of geomagnetic H component each show a sharp maximum within about ± 3° from the magnetic equator, suggesting an association between equatorial Es and equatorial electrojet currents. Knecht2 has described the characteristics of equatorial Es (Es−q). First, it regularly occurs during daylight hours in a narrow belt along the magnetic equator; second, it is always transparent to probing by radio waves; third, it usually displays a well defined lower edge lying between 100 and 110 km, giving scattered and diffuse echoes above the principal echo; fourth, in well defined cases the diffuse echoes are contained below a sharp upper boundary that starts at about ƒ0E and increases in height with increasing frequency. The time of first appearance of the Es−q in the morning and the time of disappearance in the evening has been shown to be controlled by the age of the Moon, and this effect has been related to the corresponding variations of the equatorial electrojet2,3. Close correlations have been established between the dips in ƒEs and the H component of the magnetic field at equatorial latitudes4,5.

Link... https://www.nature.com/articles/physci237073b0

Addendum...

Anton Petrov gives some more information about this phenomenon in this video...

4000km+ opening on Band 2 from Indonesia to SE Australia - 7th Jan 2021

 

Very long distance openings on the VHF bands are always of interest and one such instance happened back on the 7th of January 2021 when Leigh, VK2KRR in New South Wales in Australia managed to log and record several FM Band 2 radio stations from Indonesia.

Normally with Sporadic-E propagation, the maximum distance is around 2300 kms. In this case, VK2KRR heard FM radio stations on the 88 to 108 MHz band from Indonesia, a distance of about 4000 to 5000 kms!

While a number of Indonesian stations were recorded, it looks as if it was difficult to get a positive ID on the exact location for each one. There was however a positive ID of RADIO FBI on the island of Bali on 91.8 MHz and at a distance of  4380 kms.

It's likely that the propagation mode was double hop or chordal hop Sporadic-E. While this is pretty common on lower frequencies like 50 MHz, it is much rarer at the Band 2 frequencies of 88 to 108 MHz.

A full list of videos from the opening on the 7th of January can be viewed HERE.

New 144 MHz beacon on St Helena Island heard over 3000kms away in South Africa - 1st March 2021

Back in February of 2021, I had a post up about the new 144 MHz on St Helena Island in the South Atlantic. Now we have the first reception report!

On the 1st of March 2021, Charles ZS1CF in Cape Town heard the ZD7GWM beacon on St Helena Island over a distance of approximately 3145 kms. The beacon operates on 144.475 MHz with 25 watts on CW into a vertical antenna.

The tropo prediction map above from Pascal, F5LEN shows path and it is believed that the propagation mode was via a maritime duct just above the ocean.

This marine path from South Africa to St Helena is a relatively common occurrence and successful contacts have been made on 2m and 70cms in the last few years. It is hoped that the new beacon will give a better picture of just how often this 3000km+ path opens and encourage others to have a listen as well.

As outlined in the original beacon post, there may be a possibility of a 144 MHz trans-Atlantic path to Brazil or via TEP to Europe.

Link...

1) Update on the new 144 MHz beacon on St Helena Island (ZD7) - Feb 16th 2021

RTE to cease their DAB service at the end of March 2021

The Irish state broadcaster RTÉ have announced that their DAB digital radio service will cease at the end of March 2021. The DAB service was only transmitted from five sites near major cities and only covered 54% of the Irish population.

Sites: Three Rock (Dublin - 14kW), Clermont Carn (5kW), Kippure (15 kW), Spur Hill (Cork - 10kW), Woodcock Hill (Limerick - 10kW).

A recent JNLR report, Radio in a Digital World, compiled by Ipsos/ MRBI, found just 0.5% of adults listened to DAB. 77% of adults in Ireland listen to radio on FM.

Analysis... I'm sure there will be some people outside of Ireland who will look at this story in terms of a digital DAB V analogue FM narrative and conclude incorrectly that the attempt to replace FM with DAB failed in Ireland.

The reality was that DAB as a service was never really rolled out in Ireland and nearly half the population couldn't receive it. The radio stations on the DAB platform were the usual RTÉ suite of stations on FM as well as a few more like RTÉ Gold, RTÉ 2XM, RTÉ Radio 1 Extra, RTÉ Pulse, and RTÉjr Radio. There were no commercial radio stations so the choice was extremely limited.

DAB really offered very little incentive to buy a digital radio as nearly everything of interest could be heard nationwide on the FM service which has saturation coverage. As a service, it might have been interesting back in say the 90's but in todays world of podcasts, audio books, streaming services, smartphones, etc, a DAB radio looks like an antique.

I remember showing a DAB radio to someone back around 2005. The first question I got was 'Can I get BBC radio on it?'. Answer no, just the usual RTÉ stations plus a few more. No wonder it failed.

Maybe there will be a new digital standard like DAB+ introduced in Ireland in the future but it looks like the analogue FM service from 88 to 108 MHz is going to be around for a long time.

Timeline of DAB in Ireland
On-Air (tests): January 2006 to June 2006
On-Air (tests): December 2006 to November 2008
On-Air (public service): December 2008

On-Air (tests): to March 2001

Closure: April 2021

Free Newsletter - The Communicator March-April 2021

 

The Surrey Amateur Radio Club in western Canada produce a high quality newsletter every two months called The Communicator.

The cover and index is shown above for the March-April 2021 edition and you can find the download link HERE

Denmark heard on 144 MHz... 28th Feb 2021

 

I noticed this morning that I had heard OZ1BJF in Denmark on Sunday via FT8 on 144 MHz. It's unusual for me to hear a signal like this at the distance is 1387 kms as I'm only using a simple home made Slim Jim vertical half-wave in my attic.

Was it via meteor scatter? Tropo? There is a high pressure system over the UK so I suspect it might have been tropo.

I also heard PD1DL in the Netherlands at 921 kms which is another sign of good tropo.

I've been on the radio for the best part of 40 years and it still amazes me just how far signals travel on VHF. I never get that sense of wonder with HF bands like 20-metres.

South African activity on the 40 MHz (8m) band in 2015

In April of 2015, radio amateurs in South Africa were allocated a 10 kHz wide sliver of spectrum in the new 40 MHz (8-metre) band. The allocation goes from 40.475 MHz to 40.685 MHz which is in the middle of the 40 MHz ISM (Industrial, Scientific & Medical) band. They were also allowed a very generous output power level of 26dBW or 400 watts.

Tropo... On the 16th of August 2015, Ian Roberts, ZS6BTE, and Willem Badenhorst, ZS6WAB made the first ZS to ZS contact on the 40 MHz band over a distance of around 285 kms. 

FIRST ZS TO ZS CONTACT ON 8 Meters ( 40 MHz )

“In his telephone conversation Willem Badenhorst, ZS6WAB, informed us about the first-ever ZS to ZS contact on 40,675 MHz. It was made on Sunday 16 August 2015 between Ian Roberts, ZS6BTE, at Johannesburg and Willem at Polokwame using FSK441 and covering 288 km. ZS6WAB is equipped with a 3 element Yagi and 100 Watts. They are both looking for other ZS contacts.“

ZS6BTE was using 100 watts from an ICOM IC-746 into a 3-element Yagi on a 6m pole. It is believed that the propagation mode was troposcatter.

An attempt was made to make a contact on SSB but this was unsuccessful.

 *****

Meteor Scatter... On the 6th of September 2015, Andre Botes, ZS2ACP, in Port Elizabeth worked Willem Badenhorst, ZS6WAB, at Polokwane on 40.682 MHz FSK441 via meteor scatter.

The distance for the meteor scatter contact was 1184 kms.

* * *

Back in 2015, South Africa was the first country to allow radio amateurs to communicate on the 40 MHz band. While there was permission for beacons in the UK, Denmark and Slovenia, there was no permission for individuals to transmit.

In 2018, radio amateurs in Ireland were given permission to transmit on 40 MHz and this has sparked a lot of new interest in the band in Europe.

Hopefully in the years ahead as the sunspot numbers improve, successful contacts will be made between Europe and South Africa.

Links...
1) ZS6BTE website

Twitter poll suggests that one-third of those using FT8 on 144 MHz are using vertical polarization

How it all started... After listening for FT8 signals on 144 MHz for a few days, I was suprised to hear some signals that were well over 500 kms away. 

Considering I was using just a basic vertical Slim Jim half-wave antenna in the attic, I began wondering if everyone was really using horizontal polaziation as I had expected?

I began thinking about it and I came to the conclusion that even though FT8 is a weak signal mode on SSB and horizontal polarization is the norm, there must be some stations using just a simple 'white stick' dual band vertical up on their roof. 

After all, if you have limited space or you're active on many different bands, you may not be interested in getting a dedicated horizontal antenna for 144 MHz.

The Poll... I thought it might be interesting to see just how many people are using vertical polarization on 2m FT8 so I contacted Tim, GW4VXE who writes for several amateur radio publications and has over 4000 followers on Twitter.

I suggested to Tim that it might be interesting to put a poll up on Twitter just out of interest. Tim duly obliged and put the following poll up on Twitter for about a week.

Tim asked his followers if they used exclusively horizontal or vertical polarization or if they sometimes used either for FT8 on 2-metres.

Results... A total of 76 people voted and the results were...

Horizontal Polarization - 55.3%
Vertical Polarization - 32.9% and 
Both Vertical & Horizontal - 11.8%

There are a few caveats with the results...

1) The sample size was 76. It's not huge but I think it's still enough to give a good indication.

2) The poll was just on Twitter. Whether having the poll on Facebook or some other platform would make a difference, I don't know.

3) As Tim writes for UK based radio magazines, I would assume most of his followers are from the UK as well. Would the answer be the same in Germany, elsewhere in Europe or the USA?

In Conclusion... I think the poll results show that there are a lot more people using vertical polarization on FT8 on 144 MHz than might be expected. 

If you have a radio with 2m SSB on it then try tuning to 144.174 MHz when there is high pressure about and have a listen on FT8, you might be pleasantly suprised.

Credits: My thanks to Tim, GW4VXE for conducting the poll. You can find Tim on Twitter here... https://twitter.com/gw4vxe

Log-Periodic Antenna from the Netherlands for 27 MHz to 100 MHz

GB Antennes is a company in the Netherlands that sells a wide range of antennas including a log-periodic antenna for the low VHF band. The model pictured above is the GB Log-Per 9elm TX 27-100MHz Custom made Antenna.

Specs...

Frequency: TX 27-100MHz
Frequency: RX 24-140MHz
Connection: 50-52 Ohm coax cable
Power: 1.5kw PEP
Gain: 5.5dbd- 7.8dBi
F / B: 15-20 dbd
Maximum SWR: 1.6: 1
Wind load: 125kph
Turning circle: 2.75m
Elements: 9
Boom: 2 x 4.65m
Boom in 3 pieces total 6 pieces
Boom connectors: 4 x
Elements: 20-16mm
Boom diameter: 30mm
Insulator pieces PVC: 7x
Pole mounting Isolator piece tree PVC: 1x
Pole mounting: 2 x 52mm pipe clamps
Mounting bolts: stainless steel
Element clamps: stainless steel
Shipping box: 1x 1.60mx0.30x0.30cm
Weight: 19kg with packaging 22kg

It seems to be a pretty rugged antenna with elements ranging from 16mm to 20mm. The antenna also weighs 19kgs!

The photo above shows where the coax cable attaches to the two parallel bars used for feeding the log periodic.

The photo above shows the choke balun that goes to the feed point. The coax is an unbalanced feeder whereas the log periodic has a balanced feed point.

This antenna should have the performance of a 3-element Yagi over most of the low VHF spectrum but that performance over tens of MHz comes at a cost. This antenna currently retails at €675.

More info on the GB Antennes website... https://www.gbantennes.com/nl/gb-log-per-antennes/253-gb-log-per-9elm-27-100mhz.html

Thanks to Rob, PE9PE for the above link.

For more information on the 8m band, visit my 40 MHz page... https://ei7gl.blogspot.com/p/40-mhz.html

South African ZS6WAB beacon on 40.675 MHz

While most of the activity and interest in the new 8-metre amateur radio band is in Europe, it's worth remembering that since 2015, there has been a small 10 kHz allocation in South Africa which goes from 40.675 to 40.685 MHz.

Willem, ZS6WAB in South Africa operates a number of beacons on several VHF bands including one on 40.675 MHz. An old ICOM IC-706 is used for the CW beacon and the antenna is a 5-element YU7EF designed Yagi.

The 8m antenna is at the top of this stack

The map below shows the location of ZS6WAB in the NE corner of South Africa in the locator square KG46RB.

Considering that the ZS6WAB beacon in located in the NE of South Africa, it should easily be heard in the SW of the country via Sporadic-E propagation.

Outside of South Africa, it's a long way to any other potential activity area. The best path is probably via Trans-Equatorial Propagation (TEP) to Europe. Even though it's in the region of 8000 kms, the beacon will almost certainly be heard in Europe and it's just a case of getting people to listen and report it.

There is also potential multi-hop Sporadic-E paths to Western Australia and South America but again, it's a case of someone being interested enough to listen.

At the peak of the upcoming sunspot cycle, the 40 MHz beacon may well be heard quite easily on multiple continents including North America.

Even though this beacon has been operational for some time, there have been no reports of it on the DX Cluster outside of South Africa as of February 2021. Hopefully this post might encourage a few more people to have a listen.

***

The ZS6WAB beacon is also operational on 28.205 MHz, 50.025 MHz, 70.025 MHz, 144.400 MHz and 432.446 MHz.

For more information on the 8m band, visit my 40 MHz page... https://ei7gl.blogspot.com/p/40-mhz.html

TEP contact on 144 MHz between 3A2LU and V51E - 1990-1991

At the end of 2020, I had some posts up on the blog about some remarkable 144 MHz contacts between Argentina and the Caribbean via Trans-Equatorial Propagation (TEP). Many of the contacts were in the region of 5000 kms.

The post sparked some discussion and someone mentioned a TEP contact on 144 MHz between 3A2LU in Monaco and V51E in Namibia which had taken place in the early 90's.

The path is shown above and is in the region of 7162 kms, a really impressive distance for 144 MHz.

This contact was made in pre-internet days but from what I can tell from doing a search, 3A2LU in Monaco was running 150 watts into a 15-element Yagi. Amazingly, V51E in Namibia was using an antenna for the 160m band!

The contact which was via CW would have taken place close to the peak of solar cycle 22 so conditions must have been really good.

If anyone has any additional information about this contact then please let me know.

For examples of other long distance contacts on 144 MHz, visit my 144 MHz page.

Special permission for VK6R in Australia to operate on 35 MHz & 41 MHz back around 1989

In this post, we'll go back more than 30 years to the years 1988 to 1990 which was around the time of the peak of solar cycle 22. In an issue of RadCom (journal of the RSGB) back in 1988, it carried this interesting news item...

"Graham Rogers, VK6RO, (Western Australia) has been granted an experimental licence by the Department of Communications to transmit on the spot frequencies 35.810 MHz and 4l.750 MHz for the purpose of propagation checks, particularly to ascertain the MUF (Maximum Usable Frequency) between 30 and 50MHz during the coming peak of Cycle 22. 

FM will be transmitted, probably using a six element log- periodic Yagi covering 30 to 54MHz. with an cirp of about 83waits. Proposed callsign is VK6R. Graham will look on 28885 and 28385kHz for stations to stand by for his spot frequency transmissions. He is currently looking for a suitable transmitter."

It's worth remembering that this was a time when most people didn't have the Internet or even email. To let people know of any upcoming activity or experiments, you had to hope that people actually read about it in some amateur radio magazine.

Results... I asked Graham, VK6RO about this experiment and he said that he had managed to get a loan of a commercial low-band VHF FM radio for the tests. As for the tests, he did manage to get a report from a radio amateur in Japan on 35.810 MHz that was pre-arranged. The distance for the North-South path was in the region of 7000-8000 kms.

Graham reports that the biggest problem was the lack of activity on 28.885 MHz even though it was supposed to have been the 50-MHz liaison and crossband frequency at the time. Again, remember that there were no DX-clusters at this time.

Another problem that Graham notes was that most radios weren't able to receive between 30 MHz and 50 MHz back then.

Comment... While the tests met with limited success, the 35 MHz and 41 MHz signals would most likely have been heard in Europe near  the peak of the sunspot cycle. The problem as already noted was that most radio amateurs probably weren't even aware of the tests at the time.

It's interesting though that the licensing authority in Australia at the time was willing to grant a temporary license for these frequencies. Could it happen again for say 40 MHz? 

Maybe in the 40 MHz ISM band from 40.660 MHz to 40.700 MHz?

Would other licensing authorities around the world be willing to grant similar temporary licenses for the upcoming solar cycle 25?

Link...

1) For more information on the 40 MHz band, see a list of previous posts on this page on the blog... https://ei7gl.blogspot.com/p/40-mhz.html

Video: Yagi Antenna talk by Kent, WA5VJB

Kent, WA5VJB recently gave a talk on Yagi antenna construction and designs for the UK Microwave Society and it is now on their YouTube page.

This talk should be of interest to anyone interested in building their own Yagi antennas for the VHF and UHF bands.

The talk lasts for about 38 minutes with a short 10 minute Q&A session after it.

WA5VJB also has his own website which has antennas and equipment for the microwave bands here... https://www.wa5vjb.com/index.html

2020 Report for the 60-MHz EI1KNH beacon

The EI1KNH beacon on 60.013 MHz is currently the only operational 5-metre beacon in the world and has been on air since December of 2019. In this post, we'll look at how many times it was spotted on the DX Cluster in 2020.

A total of 6 stations spotted the EI1KNH beacon on 60 MHz during 2020 and the number of spots per individual were... EA3ERE (3), EI7BMB (3), F6HTJ (1), GW0GEI (1), NL8992 (2), SP7VVB (1).

As the map shows above, most were in the region of 800 to 1800kms from the beacon which is a typical distance for Sporadic-E signals at 40 MHz during the Summer season.

Note the reception report by GW0GEI in West Wales at a distance of 175 kms by tropo.

DX Cluster... If you do hear the beacon then make sure to report it on dx-clusters like DXSummit or DXMaps as some of the other clusters ignore spots for 60 MHz as they assume they're a mistake.

More information about the EI1KNH beacon can be found here... https://www.qrz.com/db/EI1KNH/

For more information on the 60 MHz band, go to this page... https://ei7gl.blogspot.com/p/60-mhz.html

Update on the new 144 MHz beacon on St Helena Island (ZD7)

A few days ago, I had a post about the new proposed 2m beacon for St Helena Island. Dee, ZR1DEE has very kindly sent on some additional information.

Garry, ZD7GWM is the beacon keeper and recently took delivery of  a Motorola GM340 FM radio, power supply, cables and a Diamond X700H antenna.

As of the 4th of February, the antenna still needs to be installed and then the beacon will be turned on.

More info from Dee.....  

Gary will select the beacon frequency from a list of 4 pre programmed frequencies (Channel 1: 144.475 Channel 2: 144.325 Channel 3: 144.375 Channel 4: 144.385 ) to suit .
 
Now we wait for the Diamond antenna to be erected and BEACON SWITCHED ON

* * *

Update 16th Feb 2021: Photos of the new antenna at the bottom of this post.

* * *
 
The keyer circuit is a 8 pin PIC12F675 chip fed to the input of the Motorola  GM340 FM radio

Additional information about the beacon...
Call sign of the beacon  ZD7GWM
QRG – 144.475 frequency
Grid locator IH74DB
QTH LONGWOOD ISLAND OF ST HELENA
Antenna type DIAMOND X700H
Height above sea level  545M
Height above ground  10M
Antenna direction OMNI-DIRECTIONAL
Horizontal or Vertical  VERTICAL
Power output  20 W
Keying – mode CW
Machine Generated Mode if applicable
GPS coordinated  S 15⁰ 56’ 54.68  W005⁰ 41’ 02.34 (-15.9485  -005.6840 )
Beacon status activated soon
Beacon Keeper GARRY MERCURY ZD7GWM

Analysis... Let's have a look at where St Helena is and who is likely to hear this beacon.

Video: Amateur radio construction with Steve Hartley, G0FUW and Pete Juliano, N6QW

 A video titled 'Amateur radio construction with Steve Hartley, G0FUW and Pete Juliano, N6QW' was recently posted on YouTube by the RSGB as part of their ongoing Today at 8 talk series.

The first part of the talk (1:09 to 35:30) is by Steve, G0FUW as he introduces the subject of making your own radios and circuits. This section is aimed at beginners and is a good place to start.

The second part of the talk from 35:30 to 1:17:00 by Pete, N6QW covers more advanced designs and is aimed at more experienced experimenters.

The Q&A session goes from 1:17:00 to 1:39:23.

Video: Starting out in Microwave Bands with Neil, G4LDR

As part of their Tonight at 8 series, the RSGB had a video presentation recently from Neil, G4LDR about getting started on the amateur radio microwave bands.

The talk itself is about 1h 15m in length and it is followed by a 20-minute Q&A session.

The video covers propagation, antennas and equipment for the amateur bands from 1.3 to 10 GHz.

FT8 signals heard on 144 MHz - Sun 14th Feb 2021

As my 10m antenna is out of action, I spent the weekend listening for FT8 signals on 144 MHz instead.

The VHF conditions weren't great but it always amazes me that I can hear signals from over 500kms away with a simple vertical Slim-Jim antenna inside the attic of my house.

Txmtr Band Mode Distance Time (UTC)

GM0HBK 2m FT8 605 km 15:11:29
M0IOY 2m FT8 556 km 14:29:44
G7LHK 2m FT8 456 km 16:55:44
G0NWX 2m FT8 454 km 14:46:44
G4TRA 2m FT8 431 km 11:58:59
G4RRA 2m FT8 337 km 11:54:35
GW1JFV 2m FT8 229 km 22:45:33
GW4VXE 2m FT8 229 km 13:26:59
EI5IN 2m FT8 197 km 12:25:44

QRT on 28 MHz as antenna cracks...

According to an old saying 'When the wind is in the east, tis neither good for man nor beast'. Or as it turns out, it's not great for antennas either!

After several days of strong easterly winds, my 10m vertical finally snapped! It's no big deal as it was a cheap and cheerful half-wave CB antenna and I had gotten four years out of it already.

The problem was metal fatigue at the top of the bottom aluminum section. The X in the photo above shows where it split... the bottom of the antenna is still there on the mast while the rest of the antenna on the right is sticking out of a hedge.

So no more reports on 28 MHz FT8 for a while. I'll have to wait for a nice dry day and see if I'll repair or replace it.

Video: Amateur Radio in the Falkland Islands

This video about amateur radio in the Falkland Islands was put up on YouTube in January of 2021 and features VP8EME, VP8NE and VP8LP.