As part of their ongoing lecture series during the COVID-19 pandemic, the RSGB had a presentation on Monday the 28th of September 2020 from Tim Kirby, GW4VXE titled 'My World of VHF'. Tim writes a popular VHF column in the Practical Wireless magazine as well as writing for other radio related publications.
In the presentation, Tim gives an overview of amateur radio operation on the various VHF and UHF bands and is a good introduction for anyone who is not aware of what these bands have to offer. The first 9-minutes of the video concern the upcoming online RSGB convention and Tim's presentation starts after that.
The IRTS recently had a news item about a 4-metre gateway in Galway in the west of Ireland.
Galway Analogue 4 Metre Gateway - Following the competition of phase one of the Galway Digital Repeater programme, attention now turns to analogue. The EI4GCG Analogue 4 metre Gateway operating on 70.425MHz, with CTCSS tones of 77Hz to access, is scheduled for bench testing in the next 2 weeks. The Echolink node number for this Gateway is 5422 and the Call sign is EI4GCG-L. The gateway will also be running Allstar and the Allstar node number is 52469. This project was sadly neglected over the years due to lack of interest. It is hoped that this might just put some activity on a band that sees little interest in the Galway area. This will not be linked into any digital system - analogue stays analogue and digital remains digital.
As the topographic map above shows, the city of Galway is screened to the south and south-west by various mountains. It's likely that coverage of the new 4-metre gateway will be mainly to Galway city and perhaps in as far as the midlands.
Steve Wright, EI5DD has now compiled a comprehensive manual for anyone in Ireland with an interest in the DMR, C4FM and D-Star digital modes. The 44-page document should be of interest to anyone starting off and even to established users who want to get a better understanding of the various digital systems.
While the guide is primarily aimed at radio amateurs in Ireland, a lot of the material covered should be of interest to interested parties in other countries as well.
At a press conference on Tuesday the 15th of September 2020, scientists from NASA and the National Oceanic and Atmospheric Administration (NOAA) announced that Solar Cycle 25 has officially begun and the actual sunspot minimum between cycles 24 and 25 had occurred in December of 2019. In a previous press release in December of 2019, the panel of scientists had predicted that the minimum would occur during a period stretching from October 2019 to October 2020 i.e. April 2020 +/- 6 months.
As with all sunspot cycles, it's only several months after the minimum that scientists can look back and be sure of when it occurred. There was however some signs that we had passed the peak as there was an increase in the number of sunspots which had spotted recently with the correct polarity for cycle 25.
Ultra-violet image of the sun at the sunspot minimum
The next sunspot maximum is predicted to occur in the middle of 2025 and the peak is expected to be the same in intensity as Cycle 24.
What does all this mean??? ... In the short term, not a lot will change. For stations in northern latitudes, the upper HF bands of 15m, 12m and 10m will struggle to open and when they do, it will tend to be over North-South paths.
In the second half of 2021, things should start improving and by 2022, we should start seeing more openings on East-West paths.
By 2025, we should see worldwide openings on 28 MHz but the 50 MHz band is unlikely to be as spectacular as say Cycles 22 and 23 back in 1989 and 2001. At the sunspot peak, there will probably be plenty of North-South openings on the 6 metre band but the multi-hop openings East-West may be more of an issue.
Digital Modes ... It's very likely that Sunspot Cycle 25 will be the first one where digital modes like FT8 will dominate. This may well allow some propagation paths to appear that may not have been so obvious on SSB or CW. Interesting times ahead.
During the current COVID-19 pandemic, the Mid-Ulster Amateur Radio Club are continuing with their successful Tuesday night lecture series. Recently, they had an interesting talk on VHF Propagation from meteorologist Jim Bacon, G3YLA.
The video above can be broken down as follows...
00:00 to 07:00... Introduction
07:00 to 10:25... GB2RS VHF Propagation Report - A brief outline of how the weekly bulletin is put together for the RSGB news.
10:25 to 28:30... Tropospheric Propagation - In this section, Jim covers elevated and surface ducts as well as the best time to watch any high pressure weather systems.
28:30 to 1:12:30... Sporadic-E - This section covers meteors which are the fuel for Sporadic-E and the various trigger mechanisms like atmospheric gravity waves due to mountains, thunderstorms and changes in the Jet Stream.
1:12:30 to 1:13:50... Rainscatter - This mode of propagation at microwave frequencies is briefly covered.
1:13:50 to 1:21:20... Propquest - Sporadic-E prediction website
1:21:20 to 1:23:30... Pulling it all together - GB2RS VHF Propagation Report
As outlined in a previous post, a new DMR repeater on 70 cms should be on air near Cork City in the next few week. It will be co-sited with the existing EI7FXR analogue FM repeater at Farmers Cross near Cork Airport.
COMREG has issued a licence call EI7FXD for the new DMR repeater with an output frequency on 430.250 MHz The input is 9 MHz higher on 439.250 MHz. This configuration is usually designated as DVU-R20.
The colour code will be 1.
The Brandmeister ID of the repeater will be 272015 should anyone wish to monitor the Brandmeister dashboard and hoseline, when it becomes active.
EI7FXD Coverage... The map below shows the approximate coverage out to about 60 kms.
A lot of the more distant coverage in Green is just the tops of hills so it's probably more appropriate to look at the close in coverage.
The Farmers Cross site overlooks Cork City so there should be saturation coverage there. Anyone with a DMR handheld should be able to access it.
Anywhere in the shadow of hills is likely to have problems on 70cms. e.g Blarney, Inishannon, Bandon, Mallow, Fermoy, Glanmire & Passage West.
The coverage on the N25 to the east should be good as far as the Youghal by-pass. After that, there is coverage from the Clashmore repeater EI7CDD.
Coverage on the M8 motorway to Dublin is good until Watergrasshill. Once you crest the hill, coverage may be a problem.
The same applies on the N20 north to Mallow. Coverage ends just north of Rathduff.
On the N22 to the west, there should be good coverage until Lissarda. After that, screening from hills will be an issue.
It is expected that the new repeater will be on air before the end of 2020.
Bit by bit, the DMR amateur radio digital network around Ireland is gradually improving. The digital EI7WCD repeater in the east of Waterford county started off in Tramore on the coast, then moved into Waterford city and was recently moved to a high site in the city.
The coverage of the digital repeater should now be similar to the FM repeater EI7WCD which is shown above. The improved coverage should fill in the gaps between Mt.Leinster to the north and Clashmore to the west and provide saturation coverage of Waterford city.
Report below from the Southern Ireland Repeater Group....
Major upgrade work was carried out to the Southern Ireland Repeater Group's 70cm repeater EI7WDR on 433.275 MHz at Carrickphierish in Waterford city on Saturday August 29th. All equipment including antennas and cables were replaced. The Motorola MC Compact repeater which had been in service on the site since 2004 was replaced with a Motorola MTR2000 which has a higher power output than the previous unit.
The antennas were replaced with two Diamond SE-50s and the feeder cable upgraded to Andrews Heliax LDF4-50. A Sinclair Q3220E duplexer replaced the old one which allowed the repeater use one antenna for TX and RX freeing up the second antenna for use with the EI7WCDdigital repeater which was also installed on the site as part of the upgrade work.
On site were Francis EI9KT, Gareth EI7FZB, Nicky EI3JB, Neil EI3JE and John EI8JA.
The work carried out should greatly improve the repeater's coverage and users should note that the EI7WDR repeater on 433.275 MHz now requires a CTCSS tone of 103.5 Hz to access it.
Signal reports would be appreciated and can be emailed to: sirnrepeaters AT gmail DOT com.
In a previous post, I reported on the first ever trans-Atlantic contact between the Canary Islands and the Caribbean on 144 MHz. As with many other posts, this generated some discussion online and I was interested to read that the first 144 MHz trans-Atlantic report to the Caribbean was back in 2015 by PJ4VHF.
To be honest, I can't remember seeing this before and it's possible that I did read it but forgot about it. As I keep a record of the 2m trans-Atlantic openings on my 144 MHz page, I thought it only right that I should do up a post about it and have a record of it here on the site.
Dave Pederson, N7BHC operated from the island of Bonaire in the Caribbean as PJ4VHF from February 2012 to June 2019. While there, he operated on the 50 MHz, 144 MHz and 432 MHz bands.
The above photo shows the antennas used by PJ4VHF at about 12 metres above ground level...a 5 element Yagi on 50 MHz (M2 6M5X), a pair of stacked 13-element Yagis on 144 MHz (Cushcraft 13B2) and a 43 element Yagi on 432 MHz (M2 43-9WL).
On the evening of the 6th of May 2015, PJ4VHF heard the Cape Verde D4C beacon on CW on 144.436 MHz for about 90 minutes (01:00 to 02:30 UTC). The distance across the Atlantic was 4,694 kms (2,917 miles).
The D4C beacon was running 20 watts into a 5-element Yagi and the CW signal was reported as being 10dB out of the noise.
The video above shows the reception of the D4C beacon on the 6th of May 2015. The morse code message reads... D4C/B HK76MV DE D4C/B HK76MV
The reception report was subsequently confirmed by QSL card...
From the ARRL News..... Pedersen, PJ4VHF/N7BHC, on Bonaire copied a 2 meter CW signal from the D4C/B beacon on 144.436 MHz at Cape Verde via tropospheric ducting on May 6 (0100-0230 UTC). Bonaire is in the Caribbean just north of Venezuela, while Cape Verde is off the coast of Africa, west of Senegal — a distance of nearly 3000 miles.
The D4C beacon runs 20 W and is about 750 meters above sea level. Pederson was able to confirm the transmission with the beacon operator, HB9DUR. He was using a Kenwood TS-2000 and two 13 element Yagis.
“I had parked my VHF array pointing west for minimum wind resistance,” Pederson told ARRL Propagation Contributing Editor Tad Cook, K7RA. “Tuesday evening [May 5] I was doing some paperwork in the shack and rotated the beams back east at 0100 UTC to prepare for listening all night. To my amazement, I started copying CW while the beam was still 30° off the D4C bearing.”
D4C contest site on top of a mountain on the Cape Verde Islands
Later in June of 2015, NP2X received signals from a German ham visiting Cape Verde one night, and a couple of nights later he was heard by the German visitor on D4, but unfortunately no two-way contact was made.
At the time in 2015, the D4C contest site was unmanned for most of the time but in later years remote operation become possible. The reception report by PJ4VHF showed that a trans-Atlantic sea path by tropo on 144 MHz was possible and this encouraged others to make the effort.