Saturday, October 24, 2020

Upcoming ZOOM presentation about the communications system for Ireland's first satellite - EIRSAT-1

 

EIRSAT-1 is due to be released from the International Space Station sometime in 2021 and this will be Ireland's first satellite in space. See previous post.

South Dublin Radio Club are organising a special ZOOM presentation with two of the EIRSAT-1 team members on Tuesday the 27th of October 2020 at 9pm Irish time (21:00 UTC).

During the presentation, they will discuss how they will communicate with the satellite from the ground station at University College Dublin and how others can listen in and contribute as well.

For  access to the ZOOM meeting, South Dublin Radio Club can be contacted here... https://southdublinradioclub.weebly.com/contact.html


Friday, October 23, 2020

Virtual tour of the historic Swedish SAQ transmitter operating at 17.2 kHz

 


South Dublin Radio Club had an interesting Zoom presentation on the 20th of October 2020 about the historic SAQ transmitter in south-west Sweden.

This transmitter operated at the very low frequency of 17.2 kHz and was established in 1924 to send telegrams across the Atlantic to the USA. Not long after its opening, low frequency stations of this type were superseded by those using the more efficient short wave bands.


What makes SAQ unique is that it is the last surviving transmitter of its type in that it generated the radio signal by mechanical means. See the photo below...


The electric motor on the right provides the mechanical force. The gearbox steps up the speed by a factor of three. The RF generator on the left is an alternator operating at 17,200 Hertz or 17.2 kHz.

The transmitted power is then fed to an antenna which is 2.2 kms in length.

The one-hour presentation is now available on YouTube...

Links...

1) Grimeton SAQ website

Wednesday, October 21, 2020

TEP openings on 144 MHz between Brazil and the Caribbean - Oct 2020

 


With Trans-Equatorial Propagation (TEP), zones of high ionization occur either side of the geomagnetic equator in the F layer of the ionosphere. What makes the mode so interesting is that it can allow propagation on the VHF bands from 50 MHz to 144 MHz.

As the zones of ionization is roughly 400kms above ground level, the propagation paths achieved are in the region of 4000 to 5000 kms, much greater than what might be usual with Sporadic-E.

TEP propagation normally peaks around the equinox and there have been some interesting contacts made recently between the south of Brazil and stations in the Caribbean.


One such example was a recent contact on 144 MHz between FG8OJ in Guadeloupe and PY2PAL in Brazil. On the map above, the position of the actual equator is shown in Blue while the Geomagnetic Equator is shown in Red.

You can hear the SSB contact on 144.299 MHz below...

Note the curious warble on the signal. The distance was 4455 kms which is pretty impressive for 2-metres.

Saturday, October 17, 2020

ZOOM presentation about the SAQ LF transmitter in Sweden coming up on Tues 20th Oct 2020


The SAQ station in Sweden is a low frequency radio station that uses a mechanical alternator to transmit on 17.2 kHz. This was established back in 1924 to send telegram traffic across the Atlantic to North America.

It is a listed UNESCO site and it sends out a special transmission on this very low frequency twice a year.

On Tuesday Night 20th October 2020, South Dublin Radio club will be hosting an online meeting on ZOOM at 8pm (19:00 UTC). During it, Ola Hervall from Sweden will give a virtual tour & presentation of the SAQ station.

For  access to the ZOOM meeting, South Dublin Radio Club can be contacted here... https://southdublinradioclub.weebly.com/contact.html

Friday, October 16, 2020

Videos from the 2020 RSGB Convention


Due to the ongoing COVID-19 pandemic, the annual RSGB convention was held online on the 10th of October 2020. They had two video streams going for 8 or so hours which contained talks on a wide number of subjects.

* * * * *

Video stream 1... 
An introduction to... This video stream is aimed at beginners and the timeline for the videos is shown below.


17:30 - Keynote address: Eric Swartz, WA6HHQ - From the K2, and a box of parts, to the technology and key features the K4. A behind-the-scenes look at a 22-year adventure of hard work, luck, technology and excitement at Elecraft. (Interesting look at the history of Elecraft. The main presentation is up to 52:15. Q&A lasts until 1:07:00)
1:14:20 - The small station: Joe Chester, M1MWD.
2:14:00 - Turning amateur radio into an adventure Kevin Richardson, G0PEK and Lauren Richardson, 2E0HLR
3:14:15 - The magic of six metres Chris Deacon, G4IFX
4:14:00 - How to get the most out of your dealer for your part-exchange Martin Lynch, G4HKS
5:14:20 - A pictorial introduction to data modes Mike Richards, G4WNC
6:14:10 - Antenna modelling with MMANA-GAL Steve Nichols, G0KYA
7:14:20 - Why radio and weather go together… Jim Bacon, G3YLA 

* * *

Video Stream 2...
Learn more about …This second video stream is aimed at a more experienced audience.


18:00 - Keynote address: Eric Swartz, WA6HHQ - From the K2, and a box of parts, to the technology and key features the K4. A behind-the-scenes look at a 22-year adventure of hard work, luck, technology and excitement at Elecraft. (Interesting look at the history of Elecraft. The main presentation is up to 52:45. Q&A lasts until 1:07:30)
1:15:30 - QRO Magnetic Loop Antennas Rael Paster, M0RTP
2:15:00 - VHF propagation and weather Jim Bacon, G3YLA
3:15:00 - Having fun with HF contesting Olof Lundberg, G0CKV
4:16:00 - Ionoscatter on 50 and 144Mhz Palle Preben-Hansen, OZ1RH
5:15:00 - VHF/UHF radios for contesting and DX-ing Alwyn Seeds, G8DOH
6:15:00 - DSP: Underlying Concepts William Eustace, M0WJE
7:18:30 - Take your CW to the next level Bruce Pea, N9WKE

Saturday, October 10, 2020

EI DMR registrations at the end of Q3 2020

 

The above chart shows the number of DMR (Digital Mobile Radio) registrations by EI stations for every quarter up to the end of Q3 2020. The first DMR numbers were issued in 2015 and this peaked with a surge of interest in 2017. After that, the number of registrations per year slowed and dropped by about 30% to a lower level.

It now looks as if 2020 has seen a rebound in the registration numbers with the numbers at the end of Q3 2020 already ahead of the total for 2019.

The first quarter of 2020 had 19 new registrations but 10 of these were for club call signs which will probably never be used. The second and third quarters were for individuals and show a renewed growth in interest and numbers. Even if the club calls are removed, it looks likely that 2020 will end up as the second highest year yet in terms of new DMR registrations.

As of the end of Q3 2020, a total of 229 DMR numbers were issued for EI calls. If the club calls and duplicates are removed then 192 individual EI stations have DMR numbers.

Thursday, October 8, 2020

Change of Irish Coast Guard Frequencies

 

This might be of interest to anyone who monitors or listens to traffic on the Marine VHF band.

The channels / frequencies for the Irish Coast Guard in the locations shown above are changing during the period of the 6th of October to the 14th of December 2020.


Video about EIRSAT-1: Ireland’s first satellite (NOT AMATEUR RADIO RELATED)


EIRSAT-1 is Ireland’s first satellite and a team of students in University College Dublin (UCD) are designing, building, testing and will launch this satellite as part of the European Space Agency (ESA) Fly Your Satellite! Programme.

EIRSAT-1 stands for the Educational Irish Research Satellite 1. It is a satellite about the size of a shoe box, called a CubeSat and will be controlled from a ground station on the roof of the UCD School of Physics and collect data from the three science experiments on-board.

The first experiment is a novel gamma-ray detector, GMOD, which is being developed in UCD. GMOD will detect gamma-rays from both cosmic and atmospheric phenomena. 

The second experiment, EMOD, consists of a payload developed with Irish company, ENBIO Ltd., to monitor the in-flight performance of their thermal spacecraft treatments, SolarWhite and SolarBlack. 

The third experiment, Wave Based Control (WBC), is a novel attitude control algorithm, developed in the UCD School of Mechanical and Materials Engineering, which will be tested for the first time in space on EIRSAT-1.

The satellite was due o be delivered to the European Space Agency (ESA) in 2020 but this will probably be delayed due to the COVID-19 pandemic. Once launched, it is expected to last 6 to 12 months.

The video below gives a good overview of the project...


Some RF info...

On-board Communications: The on-board CMC (Common Mode Current) transceiver is the space-qualified CPUT VUTRX transceiver supplied by ClydeSpace. The communications system uses UHF downlink (430-440 MHz) and VHF uplink (140-150 MHz) bands. The transceiver provides 9600 baud downlink and 1200 baud uplink, and implements a GMSK downlink and AFSK uplink configuration. The AX.25 protocol is used for uplink packets, while a CCSDS convolutional encoder may be used for downlink. 

ADM (Antenna Deployment Module): EIRSAT-1 will use a custom ADM designed and built at UCD which will be mounted on the -Z end of the satellite deploys two dipole antennas, one for UHF downlink and one for VHF uplink. Both dipoles are composed of two tape spring antenna elements, deployed from opposite sides of the module, as seen in many previous and COTS antenna designs. The elements are 5 mm wide, made from a Copper Beryllium alloy and attached to spring loaded doors at each side of the module. They are coiled inside the ADM before deployment, within the 7 x 100 x 100 mm overall dimensions of the module. When EIRSAT-1 is clear of the CubeSat deployer the ADM will activate a burn wire release mechanism allowing the module doors to open and the elements to uncoil into their operational positions and stay in that configuration for the remainder of the mission.

Wednesday, October 7, 2020

Radio amateurs in the USA to lose the 3.4 GHz microwave band

 

In a ruling issued on the 2nd of October 2020, the Federal Communications Commission (FCC) in the USA announced that the amateur radio service is going to lose access to the 3.4 GHz microwave band. It is proposed that the spectrum from 3.3 to 3.55 GHz be cleared for 5G networks.

Up to now, radio amateurs in the US had a secondary allocation from 3.3 to 3.5 GHz based on a non-interference basis to primary users. The FCC have now proposed clearing 3.4 to 3.5 GHz in the short term and 3.3 to 3.4 GHz at a later date.

Excerpt from the ruling regarding the amateur allocation...

Tuesday, October 6, 2020

The ADIF format now includes the new 5m & 8m bands

 



Amateur Data Interchange Format (ADIF) is an open standard for the exchange of data between various amateur radio software packages from different vendors. For example, it allows for the import and export of data between various logbook programmes.

In the most recent edition updated on the 2nd of September 2020, the new 5-metre (60 MHz) and 8-metre (40 MHz) bands were added.

I.C. Changes from Previous Version
These changes from the previous version may necessitate application code or data changes:
Addition of the FST4 submode to the MFSK mode in the Mode and Submode Enumerations.
Addition of the 5m and 8m bands to the Band Enumeration.
Addition of ARRL-10-GHZ and WW-DIGI to the Contest-ID Enumeration.
(Released ADIF Version 3.1.1, updated 2020/09/02)

While this in itself is a small step, it is part of the process of having 5m & 8m accepted as new amateur radio bands.

(Thanks to Gintas, LY2YR for the heads up on this)

Link...

Monday, October 5, 2020

EI Digital Repeater Network on 2m & 70cms - Q4 2020

The amateur radio digital network of repeaters on the 2m & 70cms bands in Ireland is gradually changing and evolving and it is sometime hard to keep track of all the changes.

Steve Wright, EI5DD has very kindly put together an 'EI Digital Network Data Card' which makes things easier to follow.


The list of frequencies is shown below...


The one obvious gap in the EI Network is the lack of a digital repeater or gateway covering the Dublin area. It's an odd situation to be in as it might be expected that any new digital network would start in the capital Dublin and then spread out. It seems as if the opposite is happening.

For more information about amateur radio digital networks in Ireland, see this previous post.

Saturday, October 3, 2020

Successful 5.6 GHz ATV test in Cork Harbour

As part of the ongoing Cork VHF Group nets on Tuesday evenings, we hold an experimental night whenever there is a fifth Tuesday in the month. On a previous evening, we experimented with sending and receiving Slow-Scan TV pictures on 2-metres FM using apps on Smartphones. For the fifth Tuesday of September 2020, the group experimented with Amateur TV signals at 5.6 GHz.

For the experiment, Jim, EI8GS went portable to the town of Cobh and set up his ATV gear to point at Don, EI8DJ in Crosshaven. After discovering that there was no reception through a glass patio window, Don took his gear outside and successfully received an ATV signal from Jim at 5.6 GHz. The distance of the path across Cork Harbour was 4.7 kms.


The photo above looks a bit crude but it's a screenshot from my PC from a Zoom meeting of a phone pointing at another screen! What it shows are the lights from the oil refinery at Whitegate in Cork Harbour and the small string of lights to the left is the village of Whitegate itself. The tests were done when it was dark so the picture would be more relevant and clearer if it was in daylight.

The lines in the foreground are in fact superimposed by the camera. The unit is supposed to be used as an aid for vehicles reversing and the lines show the 'safe' distance areas. In this case, it was used for sending an ATV signal across Cork Harbour!


The photo above shows what Jim, EI8GS was using in Cobh. He was located at a well known viewing point high above the town allowing a good line of sight path across to EI8DJ in Crosshaven.

Jim was using 0.6 watts output power into a 40cm dish with a dipole at the feed point. 


Next it was Jim's turn to try and receive an ATV signal from Don. The receiver module is shown above and a photo of the signal received by Jim in Cobh is shown below.

Don sent a number of different test cards and this is another screen shot...


The photo below shows the set-up as used by EI8DJ...


The grey box (top left) contained a Raspberry Pi Zero which generated the sequence of test cards. 

The module in the centre with the display is a portable screen that is used by drone pilots. It has its own 5.6 GHz receiver built in.

The top right box contains the 5.6 GHz transmitter module and the antenna mounted on the outside of the box is a 4 element Bi-Square with a reflective plate behind.


The photo above shows the box containing the transmitter module with a microwave relay on the left for switching from receive to transmit. The PCB in the background with the toroid is a voltage upconverter to generate 28 volts for the coil of the changeover relay.

The FM ATV signal from the transmitter has a measured output of 0.6 watts.

In conclusion... The purpose of this initial experiment was more of a proof of concept than anything else - i.e. could an ATV signal at 5.6 GHz be sent over a line of sight path and over a modest distance of about 5 kms. The answer was a conclusive yes!

The next steps the group are looking at is maybe to look at increasing the distance and exploring more paths.

About 20 years ago, there was a small but active group on 23cms (1.2 GHz) using ATV in the Cork area. Hopefully these new experiments might reignite some interest in the mode.

Wednesday, September 30, 2020

Video: RSGB - My World of VHF with Tim Kirby, GW4VXE

 

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.

Tuesday, September 29, 2020

Update on the 70 MHz Gateway in Galway...


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.

Thursday, September 24, 2020

Digital Radio Operating Manual... by Steve Wright, EI5DD


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.

The online manual can be seen HERE

Thursday, September 17, 2020

Solar Cycle 25 has officially begun


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.

Tuesday, September 15, 2020

Video: VHF Propagation Presentation by Jim Bacon, G3YLA


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.

Video...

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

1:23:30... Q&A

Saturday, September 12, 2020

QSL card from Germany confirming my QSO with a beacon?!?!

 

I recently got a small batch of QSL cards from the bureau and one was from a short wave listener in Germany.


The only problem is that this person claimed that they heard me having a contact on CW with a beacon! I even got a 599 signal report.

A quick look at the DX Cluster shows the source of the 'reception report'. On the 29th of April 2019, I heard the German beacon DL0IGI on 28.205 MHz and I put the spot up on the cluster.

EI7GL 28205 DL0IGI/B 11:29 29 Apr 19 IO51TU ES JN57MT Fed. Rep. of Germany

A short wave listener in Germany was just looking at spots on the DX Cluster instead of listening on the radio. What's the point in sending off cards for something you didn't hear? Why bother?

Sunday, September 6, 2020

Info about EI7FXD - the new DMR repeater in Cork on 70 cms


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.

Some points...

  • 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.

Friday, September 4, 2020

Upgrade to the FM & DMR repeaters in Waterford


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 EI7WCD digital 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.

Links...

1) Southern Ireland Repeater Group