TEP opening on 144 MHz band from Japan to Australia - 3rd Apr 2024

In addition to the recent Trans-Equatorial Propagation (TEP) openings at 144 MHz from Namibia to Europe, there have also been similar openings from the far south of Japan to the north of Australia.

The map above shows the paths reported on the PSK Reporter website for the 3rd of April 2024.

In fact, there have been almost daily openings reported from at last the start of March. Here are a few of the spots from the DX-Cluster...

JA6DJS 144460 VK8VTX 11:51 02 Apr 24 FT8 CQ Australia
JA6DJS 144460 VK8AW 12:26 01 Apr 24 FT8 CQ Australia
JA6DJS 144150 VK8ZMX 12:55 31 Mar 24 SSB TNX! Australia
JA6DJS 144460 VK8AW 12:49 22 Mar 24 FT8 -03dB Australia
JA6DJS 144460 VK8VTX 11:39 20 Mar 24 FT8 CQ Australia
JA6DJS 144460 VK8VTX 12:59 19 Mar 24 FT8 CQ Australia
JA6DJS 144460 VK8VTX 1:17 18 Mar 24 FT8 CQ Australia
JA6DJS 144150 VK8AW 12:34 17 Mar 24 SSB Australia
JA6DJS 144150 VK8DNT 13:04 16 Mar 24 SB TNX QSO! Australia
JA6DJS 144460 VK8VTX 12:01 12 Mar 24 FT8 CQ -10dB Australia
JA6DJS 144460 VK8VTX 12:13 11 Mar 24 FT8 CQ Australia
JA6DJS 144460 VK8VTX 12:09 10 Mar 24 FT8 CQ Australia
JA6DJS 144460 VK8AW 11:27 08 Mar 24 FT8 CQ Australia
JA6DJS 144460 VK8NAH 11:27 08 Mar 24 FT8 CQ Australia
JA6DJS 144460 VK8AW 11:41 06 Mar 24 FT8 Australia
JA6DJS 144460 VK8AW 12:04 05 Mar 24 FT8 TNX QSO! Australia
JA6DJS 144460 VK8AW 12:21 04 Mar 24 FT8 TNX QSO! Australia

Most of the signals are FT8 with no mention of the Q65 mode. There have been a few SSB contacts as well.

The distances are in the region of 4,900kms and the southern end of the path seems to be determined by the fact that most radio amateurs in that region are clustered around the city of Darwin.

There seems to be very little activity from Japan despite the sea path to the south with possible tropo extensions. I wonder if VHF stations in Japan are aware of these TEP openings to the south?

Links...

1) See my 144 MHz page for more examples of long distance contacts.

Australian stations heard on 28 MHz WSPR over a 4-week period - Jan & Feb 2024

Conditions on the 28 MHz band have been really good for the last few weeks as can be seen from the map above which shows all of the WSPR stations that I heard from the 23rd of January to the 19th of February 2024.

In total, there are 1334 individual stations which is a lot for a mode like WSPR which after all is just a beacon mode and not designed to make two way contacts. There are a lot of interesting paths in the map but the one I will focus on here are the ones to Australia.

My location in north-west Europe is in the region of 15,000 to 17,500 kms from Australia. While it's not exactly the 'other side of the planet' i.e. 20,000kms, it's still a long way for a 28 MHz signal to travel.

In total, I heard 28 stations from Australia over the 4-week period on 28 MHz. The list is shown below...

local   y-m-d txCall txGrid rxCall rxGrid MHz                 W SNR drift kms
2024-02-15 13:58 VK6TQ OF76of EI7GL IO51tu 28.126101 20 -16 0 15139
2024-02-01 13:22 VK6MJV OF77 EI7GL IO51tu 28.126135 10 -27 0 15028
2024-01-31 12:56 VK6LDL OF77vx EI7GL IO51tu 28.126201 5 -20 1 15047
2024-02-13 12:34 VK6HQ OF87av EI7GL IO51tu 28.126028 0.2 -26 0 15071
2024-02-06 12:26 VK6CRO OG65ud EI7GL IO51tu 28.126137 0.2 -24 -2 14335
2024-02-13 12:22 VK6BMT OF78ve EI7GL IO51tu 28.126038 0.2 -25 0 15031
2024-02-03 07:58 VK5ZBI PF95ga EI7GL IO51tu 28.12613     10 -27 0 16794
2024-02-09 07:54 VK5ADE PF94hj EI7GL IO51tu 28.126084 20 -22 0 16849
2024-02-01 08:54 VK4TMT QG62 EI7GL IO51tu 28.126097 0.1 -18 0 16894
2024-02-01 08:56 VK4SA QG62 EI7GL IO51tu 28.12615     0.2 -26 0 16894
2024-02-19 08:58 VK4PK QG62qi EI7GL IO51tu 28.126134 0.2 -19 0 16923
2024-02-14 08:42 VK4NE QG62nj EI7GL IO51tu 28.126133 0.1 -26 -1 16909
2024-02-19 09:00 VK4LA QG62 EI7GL IO51tu 28.125991 0.2 -26 0 16894
2024-02-01 08:42 VK4JBY QH30jq EI7GL IO51tu 28.126168 0.2 -28 -3 15801
2024-02-19 08:42 VK4EKA QG62ap EI7GL IO51tu 28.126177 1 -7 0 16838
2024-02-19 08:58 VK4BA QG62 EI7GL IO51tu 28.126196 0.2 -20 0 16894
2024-02-03 09:10 VK4AGR QG53wg EI7GL IO51tu 28.126187 0.2 -27 0 16768
2024-02-04 09:18 VK3VJP QF12 EI7GL IO51tu 28.126022 0.2 -20 0 17273
2024-02-16 08:06 VK3KCX/1 QF22qd EI7GL IO51tu 28.12603  5 2 -14 0 17449
2024-02-18 09:46 VK3CWF QF22ke EI7GL IO51tu 28.12606 5 -25 0 17415
2024-02-01 08:18 VK3AMW QF22ir EI7GL IO51tu 28.12607  5 5 -16 0 17362
2024-01-30 08:52 VK2XSM QF56og EI7GL IO51tu 28.12605     1 -19 -1 17419
2024-02-06 08:12 VK2VJ QF57vb EI7GL IO51tu 28.12604     1 -21 1 17373
2024-02-01 08:22 VK2QQ QF55gt EI7GL IO51tu 28.126209 5 -23 -2 17427
2024-02-12 09:20 VK2KYB QF56lf EI7GL IO51tu 28.126085 5 -27 0 17410
2024-02-19 09:52 VK2HL QG56 EI7GL IO51tu 28.126156 0.2 -25 0 16406
2024-02-16 08:06 VK2GDF QF67ch EI7GL IO51tu 28.126142 0.2 -14 4 17369
2024-02-01 07:56 VK1KF QF44mr EI7GL IO51tu 28.126049 5 -22 -3 17445

The ones I find of special interest are the low power stations which are in bold running output powers of 100 to 200 milliwatts. On my side, I'm just using a simple cheap half wave vertical CB type vertical to hear all of these stations.

It's just an example of how good conditions are now on 28 MHz at the peak of the sunspot cycle and is in marked contrast to the minimum a few years ago.

Low VHF Band LIPD Licence in Australia

A lot of countries allow the use of low power transmitters at certain frequencies without the need of a licence. In this post, we'll look at the low VHF frequencies available in Australia with the LIPD (Low Interference Potential Devices) Class Licence.

Why Low VHF? With the annual Summer Sporadic-E season and at the peak of the 11-year sunspot cycle, these very low power transmitters have the potential to be heard over many thousands of kilometres.

Frequency Range - Width of band - Maximum Power - My notes

29.700 to 29.720 MHz - 20 kHz - 100mW or -10dBW EIRP* - This starts just above the 10m amateur radio band

30.000 to 30.0625 MHz - 62.5 kHz - 100mW or -10dBW EIRP* -

30.3125 to 31.000 MHz - 687.5 kHz - 100mW or -10dBW EIRP* -

36.600 to 37.000 MHz - 400 kHz - 100mW or -10dBW EIRP* -

39.000 to 39.7625 MHz - 762.5 kHz - 100mW or -10dBW EIRP* -

40.250 to 40.660 MHz - 410 kHz - 100mW or -10dBW EIRP* -

40.660 to 41.000 MHz - 340 kHz - 1W or 0dBW EIRP* - 1) Note the higher power 2) This overlaps with the ISM (Industrial, Scientific, Medical) band of 40.660 to 40.700 MHz which is implemented in most countries.

54.000 to 56.000 MHz - 2 MHz - 2.5mW  or -26dBW EIRP* - 

70.000 to 70.24375 MHz - 243.75 kHz - 100mW or -10dBW EIRP* - Note that this overlaps with the 4m amateur radio band

77.29375 to 77.49375 MHz - 20 kHz - 100mW or -10dBW EIRP* -

*EIRP - EIRP means equivalent isotropically radiated power. This is the radiated power from a theoretical point source with the radiation pattern shown as a sphere.

A worked example might be as follows...

Example 1: The antenna is a half-wave dipole with a gain of about 2.1dBi. The coax loss is 1dB. The radio transmitter would need to be limited to about 750 milliwatts to comply with the 1-watt EIRP limit. If the limit is 100-milliwatts then the power should be kept at 75-milliwatts.

Example 2: If a long length of coax was used to feed the antenna and the loss was 2.1dB. This would cancel out the antenna gain and the transmitter can be used at 1-watt or 100 milliwatts depending on the frequency.

Restrictions: Other than the EIRP, there are a few restrictions such as avoiding radio astronomy sites. The licence clause also states... "The transmitter, whether on its own or in operation with one or more other transmitters, must not cause interference to the operation of radiocommunications services" and "A receiver tuned to the transmitter will not be afforded protection from interference caused by other radiocommunications devices."

Experiments: In January of 2023, I had a post up about how radio experimenters were using very low power transmitters on the 40 MHz band and how a 5-milliwatt transmitter reached almost 6000kms. See post HERE

Links: 1) There is a small Facebook group called LIPD class licence beacons in Australia if you want to join.... https://www.facebook.com/groups/1269404663238415

2) If I come across any more low band VHF experiments, I'll keep a list of the posts on my 40 MHz page.

Square Kilometre Array Radio Telescope in Australia to cover 50 to 350 MHz

The Square Kilometre Array (SKA) is an international radio astronomy project with the object of scanning the cosmos from 50 Mhz to 15.4 GHz.

This project was originally conceived in 1991. The first 10 years were about developing the concepts and ideas. The second 10 was spent doing the technology development. And then the last decade was about detailed design, securing the sites, getting governments to agree to set up a treaty organisation (SKAO) and provide the funds to start.

There are two key sites. The SKA-mid array in South Africa covers 350 MHz to 15.4 GHz and it uses dish antennas. In this post, I'll focus on the SKA-low array in Western Australia which covers 50 MHz to 350 MHz.

The SKA-low array will be located at a remote site near Murchison in Western Australia. Bulldozers are expected to start working on the site in early 2023, with the completion date estimated as 2028. 

The array is described as follows... "a phased array of simple dipole antennas to cover the frequency range from 50 to 350 MHz. These will be grouped in 40 m diameter stations each containing 256 vertically oriented dual-polarisation dipole elements.". 

"Stations will be arranged with 75% located within a 2 km diameter core and the remaining stations situated on three spiral arms, extending out to a radius of 50 km."

While the array description is of 'simple dipole antennas', the 'Christmas Tree' antenna is actually a log-periodic antenna with two polarisation feeds. There seems to be a metallic grid underneath to maximise the gain upwards.

While the gain of each individual antenna is low... possibly in the region of 6dBd... it's the sheer number of antennas fed in phase with each other that gives the high gain and resolution.

The array will produce up to ~5 Tb/s (or ~ 700 GB/s) of measurement data, which is equivalent to downloading ~200 High-Definition movies in one second. This data will be transported via a dedicated fibre from the Murchison Radio-astronomy Observatory to the SKA-Low science processing centre located in Perth. 

As might be expected, all radio transmitters are banned from the area to maintain a low noise environment. The Murchison site is about 600kms to the north of the city of Perth and is very remote.

Videos... Sirio are probably better known to the radio community as the manufacturer of various types of CB antenna as well as some for the VHF amateur bands. Their antenna plant in Volta Mantovana (Italy) will produce 78,000 'Christmas tree' antennas which will go to Western Australia to form the low-frequency part of the SKA telescope.

1) The video is in Italian but YouTube does a good job of translating it...

2) This second video titled 'Making the SKA telescopes a reality: the next chapter' gives an overview of the SKA project.

It is expected that the Square Kilometre Array project will contribute to many areas of radio astronomy.

These include...
Signals emitted in the first few hundred million years after the Big Bang.
Trace the full history of hydrogen, the most abundant element in the Universe.
Detect hydrogen's presence even before great clouds of it collapsed to form the first stars.
Fast radio bursts which output the equivalent of an entire year's worth of energy from our Sun in just a fraction of a second.

Links...
1) For more information on the SKA project, go to https://www.skao.int/

2700km opening on 144 MHz in Australia - 20th Dec 2021

Monday 20th December 2021: The Great Australian Bight is the area of water just off the south coast of Australia and is well known for producing some fine tropospheric ducts. 

On what was the 21st of December in Australia, 144 MHz WSPR signals were exchanged by VK6NI and VK2KRR on a path that was just under 2700kms.

UTC (y-m-d)         TX         txGrid RX rxGrid         MHz         W SNR drift km
2021-12-20 21:02 VK2KRR QF34mr VK6NI OF85pa 144.490562 20 -18 0 2696
2021-12-20 21:26 VK2KRR QF34mr VK6NI OF85pa 144.490553 20 -22 0 2696
2021-12-20 21:42 VK2KRR QF34mr VK6NI OF85pa 144.490552 20 -25 0 2696
2021-12-20 21:48 VK2KRR QF34mr VK6NI OF85pa 144.490553 20 -19 0 2696
2021-12-20 20:58 VK6NI OF85pa VK2KRR QF34mr 144.490427 10 -18 0 2696
2021-12-20 21:18 VK6NI OF85pa VK2KRR QF34mr 144.490427 10 -20 0 2696
2021-12-20 21:38 VK6NI OF85pa VK2KRR QF34mr 144.490427 10 -7 0 2696
2021-12-20 22:22 VK6NI OF85pa VK2KRR QF34mr 144.490427 10 -24 0 2696

The tropo opening seems to have lasted about an hour.

There was also a 2000km tropo opening on 144 MHz between Australia and New Zealand on the same day.

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

Australian authorities turn down request for 70 MHz allocation

There was a news item on the Internet recently about how the Australian regulator was not considering an allocation at 70 MHz for radio amateurs.

“We note the continued interest in this band from the amateur community. The ACMA will not be further investigating this matter at this time.

The ACMA considers that operating amateur services in this frequency range is not feasible as it would be inconsistent with ITU Radio Regulations and existing services are already operating in the frequency range. 

This frequency range is used by a variety of fixed and land mobile services as supported under the VHF mid band (70–87.5 MHz). Class licensed devices authorised under the LIPD Class Licence operate in the frequency range 70–70.24375 MHz.”

This was the reply to a submission to an earlier submission by the Wireless Institute of Australia (WIA) to the ACMA which essentially consisted of a single sentence... "10. The WIA still has an interest in an allocation at 70 MHz."

ITU Region 3... As can be seen from the map below, Australia is in ITU Region 3 while nearly all of the 70 MHz allocations are in Region 1 countries.

It's a pity that something like a 4m beacon couldn't be established in Australia or even a or a few experimental licences for the band.

It would be interesting to see if say someone in Perth on the west coast (VK6) could investigate if there is a multi-hop Sporadic-E path across the Indian Ocean to South Africa or up to the Middle East.

What would be good is for one of the smaller countries in Region 3 to give a small allocation for the 4m band which would then set a precedent. Even a 200 kHz wide segment of spectrum dedicated to weak signal modes would satisfy most requirements.

Australian 70cms digital record extended to 2,806 kms

Early on the morning of the 5th of December 2019, there was a remarkable tropo contact between Leigh, VK2KRR and Peter, VK6KXW on 70cms across the Australian continent. The distance was 2,806 kms and crossed over the Great Australian Bight, a part of the ocean well noted for tropospheric ducting.

This was a new Australian record for a digital contact on 432 MHz as both stations were using the FT8 mode. The previous record was 2,793 kms which was set back in December of 2016.

VK6KXW was running 75 watts from an IC9700 into a single yagi. VK2KRR was also running 75 watts from an IC9700 but his antenna was a box of four yagis.

VK2KRR's box of four yagis used for the contact. Source: VK2KRR on Facebook

The time of the contact was probably also a factor as tropo ducting is often at its best very early in the morning when the atmosphere has settled down and the sun hasn't risen yet.

The current non-digital record for the 70cms band in Australia is just a bit further at 2,862 kms. This was set between VK6KXW and VK7AC on the 17th of January 2019.

While examining both of these contacts, it can be difficult to relate to the distance of 2,806 kms and just how far it is. It might be useful for stations in Europe to remember that the distance from the west coast of Ireland to Newfoundland in Canada is 3,000kms, just an extra 200 kms.

Leigh VK2KRR has a nice website with plenty of VHF info, visit https://www.vk2krr.com/

Unusual 50 MHz opening from Australia to Europe - Wed 24th July 2019

Over the last few weeks, there have been multiple openings from Europe to Japan at 50 MHz as stations make use of digital modes like FT8 to dig weak signals out of the noise. Most of these contacts are in the region of 9,000 to 10,000 kms which suggest multi-hop Sporadic-E was the likely propagation mode.

On Wednesday the 24th of July 2019, there was a very unusual opening on 50 MHz between Europe and New South Wales in SE Australia.

Here are some of the send/receive reports from PSK Reporter for the Australian stations on the 50 MHz band...

VK3ZL...

A successful FT8 contact was made between VK3ZL and EI3KD in Ireland, a distance of 17,375 kms. This seems to have been the longest contact of the day.

VK3BD...

VK3ANP...

VK3ZYC...

VK3EW...

The opening from Europe to SE Australia seemed to be from about 07:09 UTC to about 08:20 UTC.

The graphic below shows where the sun was shining at 07:30 UTC.

The opening seemed to coincide with sunset in SE Australia.

Some notes....
1) Solar..... The solar flux was way down at 67, the sunspot number was zero and there was no sign of any type of enhancement due to a flare. It's hard to imagine there was any normal type F2 propagation which might be seen around the peak of the sunspot cycle.

2) Japan..... The opening from Europe to Australia seemed to coincide with an opening from Europe to Japan. S57RR in Slovenia was on the send/receive list for five of the six VK3 stations and this is what the 6m map was like for him on the 24th...

3) Multi-hop Sporadic-E ???.... The distances worked from Europe to Australia were in the region of 16,000 to 17,400 kms. If it was simple multi-hop Sporadic E, it would require something like eight to nine hops. What are the chances of this many Sporadic-E hops? I find it hard to believe it's possible.

4) Winter..... It's worth noting that it's winter in Australia and this is not their Sporadic-E season. There seems to be no sign that the VK3 stations were hearing any other stations via Sporadic-E, just the opening to Europe.

Theory?...... Just a thought and I'm putting it out there for others to consider. Is it possible there was TEP (Transequatorial propagation) opening from SE Australia to an area SE of Japan and then became skewed via Sporadic-E? The multi-hop Sporadic-E opening from Europe also got to this region in the Pacific?

It's possible the TEP path may have been a bit more westerly from Australia to an area closer to China.

Perhaps it's grasping at straws for an explanation but I find it just as feasible as expecting 8-9 Sporadic-E hops to line up in a row at 50 MHz for the shorter direct path.

The key difference between the two paths would of course be if the beam headings for all parties were the most direct short path ones or if they were skewed. Unless someone is using a long Yagi, it may not be so obvious at 50 MHz.

All good material for debate of course but probably impossible to prove one way or the other.

Addendum : See message below from Brian, VK3BD (Added 12th Aug 2019)...