Saturday, April 8, 2023

ZS6WAB 40 MHz beacon heard in Western Australia - 5th April 2023

Over the last few months, there have been plenty of long distance propagation paths reported on the 40 MHz band but nearly all involve at least one station in the northern hemisphere. In this post, we'll look at a recent East-West path in the southern hemisphere.

5th April 2023: Short wave listener Tony Mann in Perth, Australia reported reception of the ZS6WAB beacon in South Africa on 40.675 MHz. The distance was about 8320kms.

Tony Mann writes... "To my surprise the South African 8m beacon on 40.675 MHz, ZS6WAB, made an appearance here for over 2 hours after 0615 UTC. I am amazed it was detectable, and for so long here.

The receiver is an Icom IC-R75 with audio via usb mode. The beacon was first heard around 0615 UTC on a north facing 6m broadband dipole at 5m agl. When I rotated the dipole around to face east-west the signal was much stronger.  

The signal was audible for over an hour, peaked again 0645-0655 UTC and was visible on Spectrum Lab past 0800 UTC. The decoded morse revealed the callsign ZS6WAB and grid locator KG46RB. The great circle distance is 8320 km (5200 miles)."

Tony posted this video on his YouTube channel...

In response to this reception report, Willem ZS6WAB reports... "All my beacons from 40.675mhz /50.025mhz /70.025mhz /144.400mhz is beaming to Australia for the last month now. Ure report is the very first report since my antenna are turned to VK land."

I think there was a report of a VK8 station in the north of Australia hearing this beacon in the last 12-months but it wasn't really documented or reported on.

Analysis... While this opening was ongoing, Tony Mann took a screenshot from the Australian Bureau of Meteorology website which shows the predicted F2 layer critical frequency. This is the frequency that is returned from the F2 layer in the ionosphere when a signal is sent straight up.

The actual maximum usable frequency (MUF) is roughly three times the critical frequency i.e. a signal at perhaps an elevation of about 5 degrees above the horizon. The map suggests a MUF of maybe 3 x 11 MHz / 12 MHz = 33-36 MHz. It's not exact but it suggests that a path in the low VHF spectrum (30-40 MHz) might be possible.

The second thing to note from the graphic above is that conditions in the ionosphere are now better in the southern hemisphere now that we have passed the equinox. 

If we consider how many good east-west paths there were in the northern hemisphere in January to March then there should be similar east-west paths on the 40 MHz over the next few months from South Africa to Australia and South America and from Australia to South America.

It really is just a case of getting more people transmitting and listening.

Link... For more information on the 8m band, see my 40 MHz page.

Tuesday, April 4, 2023

Results of the Low-Band VHF Propagation tests by EI9KP - 1st & 2nd April 2023

In a previous post, I outlined how Phil, EI9KP was carrying out propagation tests on 32 MHz to 36 MHz on the 1st & 2nd of April 2023.

Phil, EI9KP send on the following report... "I ran the time slot beacon test 32...36 MHz over the weekend of 1-2 April 2023, unfortunately few reports.  

F2 propagation favoured a north/south path, mainly a zone across north Africa (simulation).  SFI (Solar Flux Index) was in a trough at 125 and MUF over Ireland was very low at 25MHz, touching 28MHz by late afternoon.

I have N3IZN in California and K9MY in Illinois reporting they were listening but nothing heard. 

Michael EI3GYB reported on your blog that he could receive the beacon on all frequencies, from his QTH it would have been a diffracted ground wave.

The beacon software, hardware, dipole and band pass filter all performed without any problem.

I am planning a repeat test in about 4 to 6 weeks, hoping for higher SFE and perhaps sporadic-E."


Michael, EI3GYB is located about 30kms to the south-east of EI9KP and sends on the following report... "I monitored the beacon on both days during several hours of the days at my QTH in locator io53ot.

I used two transceivers- an ICOM IC-7200 and a YAESU FT857D. Both TRX had Windom antennas for reception.

I copied the signals on all 5 frequencies with both TRX. The signals on the Yaesu were a bit weaker than on the ICOM. The signal meter showed no bar on the Yaesu- while on the ICOM I had at least one bar, sometimes two.

33,34,35 and 36 MHz all had the same signal strengths- I'll give it a 51 on the Yaesu and a 52 on the ICOM. The signal on 32 MHz was weaker- on both TRX. I'll give it a 31 on the Yaesu and a 41 on the ICOM.

There was a noticeable fading on all 5 frequencies. Slow QSB, not too deep though."

Larry, VO1FOG in Newfoundland reports listening on both days on CW and hearing nothing. Over the last few days, I have heard the WSPR signal on 28 MHz from VE1VDM in Nova Scotia many times but this was often after 19:00 UTC. Perhaps the test beacon at 32-36 MHz was turned off a little early for the path to North America?

Paul, MI3LDO in the north-west of Ireland reports that the last decent trans-Atlantic opening at 34 MHz in his location was back on the 21st of March so perhaps the test was a little too late in the season for good east-west F2 layer propagation.

Analysis... As we're now in April, F2 layer propagation in the northern hemisphere is getting noticeably worse as we head towards the Summer. While there was plenty of propagation on 28 MHz over the weekend, it did seem to struggle to get up into the low band VHF region especially on east-west paths.

It seems like the test period was a bit late for F2 propagation and too early for the summer Sporadic-E season. Hopefully that will have changed for the next test in May when there should be plenty of Sporadic-E to Europe.

It was interesting to note that EI3GYB was getting slow fading over a short 30km path.

Sunday, April 2, 2023

Opening on the 50 MHz band from Europe to Fiji - Short path or Long Path?

Andreas, SV2JAO in Greece sent on a report of his JT65 signal being heard by 3D2AG in Fiji in the Pacific on 50 MHz (6m) band on the 31st of March 2023. This then raises the question... Was it short path or long path?

The screenshot above was taken by Andreas from the PSK Reporter website just after the signal was heard. That site will always by default show the shortest path but it doesn't mean that it's correct.

3D2AG to Europe... First of all, I checked the PSK Reporter website myself and I had a look at the paths from Fiji to Europe.

As you can see from the map above, there were three stations in Europe. These were the reports in the last 24 hours...

31st March 2023...
Txmtr Rcvr Band Mode Distance Time (UTC) SNR
IZ8FWN 3D2AG 6m JT65 17124 km 22:02:50 -21
SV2JAO 3D2AG 6m JT65 16634 km 22:02:50 -23

1st April 2023...
3D2AG SV9CVY 6m FT8 16801 km 07:39:44 -19

Long path or Short path??? ...If it's on the higher HF bands or 50 MHz then the guide is to follow the sun. The JT65 signals from IZ8FWN in Italy and SV2JAO in Greece were heard in Fiji at 22:02 UTC UTC, the sun is now somewhere over the Pacific and the short path over Asia has been in darkness for quite a few hours. Conclusion, it's most likely long path.

The other path was from SV9CVY on Crete to Fiji at 07:39 UTC which is about 10 hours after the other reports. Now, the Pacific path is in darkness and the path over Asia is in sunlight. Conclusion, it's most likely short path.

This doesn't rule out that the path may have been skewed somewhat but we can't come to any conclusion about that with some information about the various beam headings from the respective stations.

In conclusion... I know the above will sound obvious to a lot of experienced radio amateurs but I do think there is a tendency for newer operators to just look at a map, see the line presented and take it as fact.

The reality is that PSK Reporter 'suggests' the most likely path, you have to use your own experience and knowledge to decide if it's correct. A good guide is to follow the sun and then decide if it's long path or short path.

1) Other examples of long distance paths on the 6m band can be found on my 50 MHz page.