Showing posts with label radio experiments. Show all posts
Showing posts with label radio experiments. Show all posts

Thursday, March 14, 2024

Low band VHF tests by Tony Mann in Western Australia - 2023


 In a previous post, I looked at the Low Interference Potential Devices (LIPD) Class Licence in Australia and how it allowed individuals to transmit with very low power in parts of the low-band VHF spectrum.

Tony Mann is a radio experimenter in Perth, Western Australia and has over the last 12-months been operating four beacons in the low-VHF bands with each one running 100 milliwatts.

The frequencies were 30.8761 MHz , 36.6073 MHz, 39.1467 MHz and 40.6864 MHz.

In 2023, several stations heard the beacons and there are shown on the map above.

Short wave listener Hugh Cocks (HC02) is in the south of Portugal. Phil, EI9KP is located in the west of Ireland. Paul, G7PUV is located in the SE of England. All three are in the region of 15,000 kms.

Otto, VK4OTZ in Queensland, Australia is about 3,700kms to the east which is pretty much ideal for one F2 layer hop.

Tony informs me that he initially made a single frequency “beacon” on 36.860 MHz for the southern hemisphere F2 season in March-May 2023. It was simple crystal oscillator modulated by a PIN diode.

By July 2023, he had a second beacon on 30.876 MHz which was still heard in Sydney via F2 up until September 2023. By that time, Hugh Cocks in Portugal was interested in trying, so he ran 30 MHz after late Sept 2023, quickly added 36 MHz, then 39 MHz by 10 Oct and finally by 29 Oct had a 4th, 40 MHz beacon running.  

The 36.860 MHz frequency was changed to 36.607 to avoid DX radar interference in Europe. The 40 MHz beacon was never received as by mid-Nov 2023 conditions had deteriorated. 

Tony's antenna is shown below...


Tony uses two vertical dipoles: On the left is a single dipole for 30.9 MHz and on the right is a folded dipole for 36-41 MHz (which works adequately on 30.9 MHz).

The beacon signal is alternately switched on for 0.5 seconds, then off for 1.5 seconds. The cycle repeats every two seconds. There is a  0.5 second gap where no power is going out.


The screen grab above from Hugh, HC02 in Portugal shows what the 39.1467 MHz signal looked like on the 11th of March 2024.

Videos... This clip from Paul, G7PUV shows reception of the 30.876 MHz signal...  



The video clip below shows reception of the 36.860 MHz signal by VK4ATZ...


Current Status - March 2024: Tony is currently carrying out propagation tests as we're close to the equinox.

Tony writes... "I am ready to resume the 07-11 UTC tests for Europe in March 2024 and I anticipate adding 00-04 UTC for the autumn F2 season in Australia."

It would be interesting to see more reports of people hearing Tony Mann's beacons. Perth to North America? Perth to South America?

If you hear anything then you can leave a comment here.

Tuesday, January 24, 2023

Results of the 34 MHz Propagation Tests - Sat 21st & Sun 22nd Jan 2023


On Saturday the 21st and Sunday the 22nd of January 2023, Phil EI9KP conducted some propagation tests on the 9m band in the low-VHF part of the spectrum. He operated a supervised beacon on 34.013 MHz for most of the daylight hours running 1-watt into a horizontal dipole with capacitive loading.

This is a report on who heard his signal over the two days.

Phil, EI9KP writes... "This 34MHz beacon experiment got people interested in listening and I am pleased to have received the reception reports below.  Also I'd like to express my thanks to Paul Logan in Co Fermanagh for twittering his followers.

Two reception reports from EI, two from Europe and to my delight a few from the USA. 

YO9FTR in Romania at 2795km received the signals on both days.  He suggested that start earlier on Day 2, in fact propagation was waiting when I switched on and he decoded the first 15 seconds of the beacon's FT8 sequence.

N2OTO in Florida is near enough twice the distance than VO1FOG in Newfoundland, on the same great circle line.

 K5YT at 6864km / 4265 miles was the greatest distance. Edward, K5YT in Texas was using a Hygain TH2-MK3 tribander @ 30m (100’) as a receive antenna.

FT8 signal received by K5YT in Texas

The USA reports suggest F2 propagation, but how many hops to FL or TX?  What about the one from CT?

YO9FTR made a long observation of the signal/SNR. This wasn't pre-arranged, however, I am thankful for the data and realised there was some pattern in it.  The resulting graph shows signal/SNR over several hours, really a nice observation of propagation.


So, I enjoyed the experiment, there's always something new to learn.

 73, Phil EI9KP"

 ~~

The map at the top of the post shows the stations in the USA that heard EI9KP on the 9m band. The map below shows the stations in Europe.


EI9KP's report... Information about reception reports collated from email, 8m Groups.io, VHFSKIP groups.io, Ei7GL blog.

21.01.2023

Beacon 34.013MHz 1W Dipole active from 10:05 till 17:15 UTC

Reception reports:

YO9FTR in the east of Romania, locator KN35XG, from 10:51 till 10:57 UTC, SNR -15 to +14 dB

N2OTO in locator EL96WI, Florida, from 13:12 till 13:19 UTC, SNR -16 to -13 dB

W1IG in locator FN31LN, Connecticut in the USA at 16:08 UTC

N4EF in locator EL98HP, Florida in the USA at 16:10 UTC using an ICOM IC-7610 with a dipole in the attic.

HB9TMC in Switzerland in locator JN46LJ, from 16:53 till 17:01 UTC

EI3GYB in locator IO53OT, over several hours during the afternoon 

Spots from PSK Reporter...
21st Jan
Txmtr Rcvr Band Mode Distance Time (UTC)
EI9KP N4EF 9m FT8 6350 km 16:10:14
EI9KP W1IG 9m FT8 4805 km 16:08:14
EI9KP HB9TMC 9m FT8 1526 km 16:53:26
EI9KP N2OTO 9m FT8 6457 km 13:12:15

22.01.2023

Beacon 34.013MHz 1W Dipole active from 08:43 till 17:15 UTC

Reception reports:

YO9FTR in the east of Romania, locator KN35XG, from 08:43 till 11:42 UTC, SNR -21 to +14 dB

K5YT in locator EM22NV, Texas, from 15:03  till 15:11 UTC, SNR from -18 to -7 dB.

N4EF in locator EL98HP, Florida in the USA using an ICOM IC-7610 with a dipole in the attic. FT8 reports from 14:48 to 15:13 UTC and also reports hearing the CW a few times at strength 329.


EI5IN in locator IO63HM, at 15:01 UTC, SNR -21 dB

Spots from PSK Reporter...
22nd Jan 
Txmtr Rcvr Band Mode Distance Time (UTC)
EI9KP EI5IN 9m FT8 120 km 15:04:29
EI9KP K5YT 9m FT8 6855 km 15:49:14

If I missed any reports then let me know.

Analysis... It should be noted that the reports above are from a beacon running just 1-watt which is pretty amazing. It just goes to show how far a signal can travel via F2 layer propagation with relatively low attenuation.

Let's have a look at a propagation map.


The map above shows the predicted coverage for a 1-watt operating at 30 MHz. It's not quite 34 MHz but it's close. The solar flux was just around 200-210 for the test.

YO9FTR... For most of the daylight hours, Romania is in the ideal spot for F2 layer propagation and reception of the beacon. The reception chart from YO9FTR further up this post shows reception of the 34 MHz signal from 08:43 to 11:41 UTC.

In the 'old days' when listening just by ear, it would have appeared that the signal was in and out, missing for long periods and then strong for a while. With a weak signal mode like FT8, we can see that the signal was actually there all of the time for three hours. The software was able to decode the FT8  signal when it was buried in the noise.

HB9TMC... It's hard to know for sure what propagation mode was responsible for the reception of the beacon signal in Switzerland. It's seems a bit too close for F2 layer. Was it Sporadic-E? Backscatter? Paul, MI3LDO heard French roads control traffic on 35/36 MHz on Saturday afternoon and thinks it was almost certainly Sporadic-E.

USA... Florida seems to be in the perfect spot for reception. It's the most southerly path and it's in the right area for the second F2 hop. Texas would seem to be at the edge of the footprint.

Overall an interesting test and a very successful one considering the relatively small number of people that would have known about the transmissions. It's also worth noting that very few people have antennas for 34 MHz and most are listening on antennas tuned for other bands.

Ireland is the only country in the world as far as I know where radio amateurs can transmit at 34 MHz (9m band). It lies pretty much half way between the 10m band (28 MHz) and the experimental 8m band at 40 MHz.

For more information about other 34 MHz tests, I'll keep the posts on my 40 MHz page HERE

Saturday, April 16, 2022

Trans-Continental opening on the 40 MHz band in the USA - 14th Apr 2022


On the 14th of April 2022, there was an interesting Transcontinental opening on the 40 MHz band in the USA.

There are currently seven US radio amateurs using experimental callsigns and licenses for the 40 MHz band. Three of these... WM2XCC in California, WM2XCW in Washington State and WM2XAN in Michigan are using the WSPR digital mode and their signals were heard by W4WLO in Alabama and N2OTO in Florida.

The WSPR reports for each of the three stations are shown below...

 Local   (y-m-d) TX txGrid RX rxGrid MHz W SNR drift km
2022-04-14 21:52 WM2XAN EN74oh WLO/O5 EM50vo 40.6636 100 -26 -4 1553

2022-04-14 22:14 WM2XCC DM13ji N2OTO EL96wi 40.663493 2 -9 0 3640
2022-04-14 22:02 WM2XCC DM13ji N2OTO EL96wi 40.663492 2 -14 0 3640
2022-04-14 21:52 WM2XCC DM13ji N2OTO EL96wi 40.663493 2 -20 0 3640
2022-04-14 21:44 WM2XCC DM13ji N2OTO EL96wi 40.663493 2 -16 1 3640
2022-04-14 21:34 WM2XCC DM13ji N2OTO EL96wi 40.663493 2 -24 0 3640
2022-04-14 21:34 WM2XCC DM13ji W4WLO/S32 EM50vo 40.663489 2 -11 0 2743
2022-04-14 21:24 WM2XCC DM13ji N2OTO EL96wi 40.663495 2 -24 0 3640
2022-04-14 21:24 WM2XCC DM13ji W4WLO/S11 EM50vo 40.663449 2 -8 0 2743
2022-04-14 21:16 WM2XCC DM13ji N2OTO EL96wi 40.663493 2 -23 1 3640
2022-04-14 21:16 WM2XCC DM13ji W4WLO/S11 EM50vo 40.663449 2 -3 0 2743
2022-04-14 21:08 WM2XCC DM13ji N2OTO EL96wi 40.663493 2 -11 0 3640
2022-04-14 20:58 WM2XCC DM13ji N2OTO EL96wi 40.663492 2 -8 0 3640
2022-04-14 20:48 WM2XCC DM13ji N2OTO EL96wi 40.663492 2 -9 0 3640
2022-04-14 20:38 WM2XCC DM13ji N2OTO EL96wi 40.663491 2 -9 0 3640
2022-04-14 20:28 WM2XCC DM13ji N2OTO EL96wi 40.663492 2 -12 0 3640
2022-04-14 20:20 WM2XCC DM13ji N2OTO EL96wi 40.663493 2 -7 0 3640
2022-04-14 20:12 WM2XCC DM13ji N2OTO EL96wi 40.663494 2 -1 0 3640

2022-04-14 21:16 WM2XCW CN88lx WLO/O5 EM50vo 40.663601 10 -20 0 3561
2022-04-14 21:16 WM2XCW CN88lx W4WLO/S32 EM50vo 40.663538 10 -27 0 3561
2022-04-14 21:06 WM2XCW CN88lx W4WLO/S32 EM50vo 40.66354 10 -17 0 3561

Some observations...

1) WM2XAN to WLO/05 (W4WLO) at 1553kms is normal enough. Some weak Sporadic-E could account for this reception report.

2) WM2XCC in California to W4WLO in Alabama and N2OTO in Florida is 2743kms and 3640kms respectively. These were the most numerous reports and are well beyond the normal 2300km limit or so for single hop Sporadic-E. In that respect, it's a very unusual opening.

3) WM2XCC in Washington state to W4LO in Alabama is 3561kms and is again an unusually long distance path.

Analysis... What caused the opening and what was the propagation mode? 

First of all, let's look at the times. The opening was at roughly 21:00 UTC which was roughly 3pm local time in the centre of the United States.

Theory 1: Double hop / Chordal hop Sporadic-E - It's possible that Sporadic-E with more than 1 hop was involved which extended the range beyond the normal 2300kms or so. Even though the Summer Sporadic-E season has started, it's still only the 14th of April. It's possible it was double hop but I think it's unlikely.

Theory 2: F2 layer propagation - The solar flux on the day was at 103 but note how the opening happened just before a major aurora.


It is often observed that there is an improvement in the upper HF bands like 28 MHz as an aurora is commencing or about to start.

At the moment, East-West paths across the USA have a maximum usable frequency (MUF) in the low VHF spectrum just above 30 MHz. I suspect the onset of the aurora caused to MUF to jump upwards and propagation via the F2 layer at 40 MHz was possible.

While we can never be 100% certain what the reason was, I think the fact the 40 MHz opening happened at the start of an aurora is significant.

In conclusion... Over the next few weeks, the Sporadic-E season will really begin to get going and I suspect there will be plenty of double hop Sp-E openings in May and June.

As the sunspot numbers improve, F2 layer openings like this will be become a lot more common and I think 40 MHz WSPR reports will be of particular value to those operating on the 50 MHz band waiting for an trans-continental opening in the United States.