Author Archives: gdars

Arthur Morris – GM1RKI SK

One of the earliest members of the club, Arthur Morris, sadly died on 17th September 2024, aged 88.

Some members of the club will be attending his funeral at Melrose Crematorium at 1300 on Friday 4th October.

Our thoughts are with his family.

73’s Arthur

Railways On The Air 2024 – Sat 28th/Sun 29th September 2024 – GB0WRH

Again some of our club members will be taking part in the Railways On The Air event.

The station will be set up in the carpark of the Whitrope Heritage Centre near Hawick on Saturday 28th September and will be operating until the afternoon of Sunday 29th September. The two Daves GM0KCN and MM0HTL will be there on Saturday with Dave HTL staying the night in the caravan and operating on Sunday.

The callsign used will be GB0WRH (Waverley Route Heritage) operating on HF bands on both days. All club members and visitors are welcome to come along and see the radio station and have a go at operating or just come along to chat.

The Whitrope Heritage Centre is run by the Waverley Route Heritage Association who have restored a length of track and sidings on the old Waverley line (1849-1969) between Hawick and Carlisle. Further details here: https://wrha.org.uk/about/

Location:
Whitrope Heritage Centre, Whitrope, Hawick, Roxburghshire TD9 9TY
Location: 11 miles south of Hawick on B6399 (Hawick to Newcastleton road).

Locator and directions:

Maidenhead Locator: IO85PH 00co
55.294320, -2.748944 (55°17’39.6″N 2°44’56.2″W) 1034ft (315m) asl
NGR: NT 52540 00279
WAB Square: NT50
Google: 9C7V77V2+MC
W3W:///jousting.windmills.wire
https://wrha.org.uk/the-association/find-us/

Satellite image showing location of Whitrope Heritage Centre carpark

https://rota.barac.org.uk/
https://wrha.org.uk/the-association/whitrope-heritage-centre/

2024 Rally and Open Day – Sunday 27th October 2024

This year’s Galashiels Rally and Open Day will take place on Sunday 27th October 2024.

This is the last weekend of October so the morning of the clocks changing back an hour.

Venue as usual is the Volunteer Hall, St John Street, Galashiels TD1 3JX.

Traders booked so far (as of 10th September 2024):
RSGB (Books, Memberships etc)
GQRP Club
Alan Clegg (Valves etc)
Mirfield Electronics (Martin Stokes)
Canny Components
Mick Hunter (Batteries etc)
Tony Kruszelnicki (TK Electronics)
Perth Repeater Group
Peter Bates GM4BYF
Ken Elliott GM4NTX
Dave Bagshaw
Bob McClements GM4CID (Used radios, antennas, hand-built equipment)
Nick Trollope G4FAT (Expert-Audio – Radio leads, electronics, components, tools, used ham radio gear etc)
Andy Robson GM8YIK (SK sale for SBRG funds from GM8IIO and GM8BDX)
John 2M0YTN
Martin 2M0KAU

Bring & Buy Stall
Catering with hot and cold refreshments

Admission: £3.00 (up slightly on previous years due to increased hall rent costs etc).
Free entry for under 16s accompanied by an adult.
CASH ONLY at the door. Change will be given but we appreciate correct change for faster entry.
Some commercial traders may have card machines but most may only take cash.

Doors open at 08:00 for booked table traders to set up.
Early entry for disabled visitors and early Bring & Buy booking at 10:45.
General admission doors open at 11:00. (All times are GMT – remember to put your clocks back!)
Note that Practical Wireless magazine wrongly states the times in BST.

Location:
The Volunteer Hall
St John Street
Galashiels
Scottish Borders
TD1 3JX
(Google Plus Code 9C7VJ57R+WV )
(What3Words///practical.diner.voltage)

Access to Galashiels by road from A7, A72 or A68 (via A6091), by bus (bordersbuses.co.uk) or by train (scotrail.co.uk).

New email for traders queries including table bookings: rallytraders @ galaradioclub.co.uk
(The address rallytables was mistakenly given out but will also redirect automatically to rallytraders.)
General enquiries about the rally (not traders) to rallyqueries @ galaradioclub.co.uk
Email is preferred as website comments may not trigger a notification with us.

Be aware most tables are now booked/reserved so any more requests will be added to the reserve list in case of any cancellations. Otherwise you are welcome to enter items to the Bring & Buy stall on the day.

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PW 144MHz QRP Contest 2024 – Sunday 9th June 2024

Again members of the club will be going up the hill to operate a portable station for the Practical Wireless 144MHz QRP contest on Sunday 9th June 2024. We will be using the callsign GM4YEQ/P.

The contest runs between 0900-1500 UTC (1000-1600 Local/BST). We’ll likely be on-site by 0915 (local) if not earlier for setting up.

We’ll be at the usual “Middle Swire” location between the Yarrow and Ettrick valleys 6 miles west of Selkirk.

All club members are welcome to come and visit and catch up for a few hours, assist with setting up or operating, or operate your own sets on HF away from urban QRM.

Or if not able to come to the site, please give us a shout on 2m simplex FM or SSB if you hear us (144.150-144.397MHz is the SSB range). Someone will likely be scanning simplex channels 145.200-575MHz through the day. The more contacts we get (even local ones) the more points we get multiplied by the number of locator squares. Calling CQ on 145.500 isn’t allowed so don’t just listen for us there (nor on the repeaters)! Individual members may be monitoring repeaters and calling channels though if you want to make contact with someone in the group.

Exchange will be signal report, serial number (if you’re not participating then give 001 for your first contact) and your Maidenhead grid reference (or approximate location if you don’t know it as it still counts as a contact just not a new grid square).

Visitors should bring their own food and drink if they’re staying all day. Bring suitable clothing in case it’s windy or wet and footwear suitable for a grass field (with sheep droppings!). Dogs under strict control.

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Moonbounce – A Science for Everyone

4 yagi antennas pointing at the sky

By John Berry GM8JBJ

On 12th May I bounced signals off the Moon.

OK, I’d been bouncing signals off the Moon ever since I put up the antenna system a fortnight before. Just that I didn’t know there was anyone on the other end to decode my 13-character message. Until, that is, on the 12th Mr Potts, callsign NC1I, replied from Massachusetts, USA.

Successful QSO between GM8JBJ and NC1I shown on WSJT-X screen.

Moonbounce (or Earth-Moon-Earth, EME) communication is a very cool thing to do. Just imagine the cred you’d get when next in a bar and you throw that out there when things go quiet.

And importantly, anyone can do it.

Background

The Moon is about 400,000km away (less at perigee, more at apogee). Hence, the flight time for a signal from Earth to Moon and back is about 2.7 seconds. The corresponding round-trip free-space path loss for a signal is a huge 400dBi – no way anyone can bridge that gap. But whilst the Moon is a poor point reflector with a reflection coefficient of 6.5%, it’s also a 3,500km diameter billboard that reflects from all points across its area. The result is a real total path loss of around 250dBi and that’s (just) low enough for radio amateurs to exploit our natural satellite to communicate almost globally.

Basic Kit

Today, almost everyone uses Joe Taylor (K1JT)’s ultra-narrow-band algorithms to code and send a very short message. The message is pared to the bone – it’s even skinnier than FT8. And using his software, WSJT-X, this is sent repeatedly. So, you need a computer, a sound card, and the application. The setup is the same as for FT8, but you’ll configure to use Q65B with a 60-second period.

Video of a transmission via the Moon using Q65B (specks on waterfall and tones in noise) on 432.093MHz at https://hamradio.engineering/moonbounce-eme/

The transmission modulates the audio of a rig and uses upper sideband (USB). The simplest bands for moonbounce are 144MHz and 432MHz. 1296MHz is another option, but above 432MHz you’ll need a high stability reference to hold the frequency steady and 23cm kit gets expensive. Of course, you could do it at any GHz frequency amateur band, but I’m assuming no-one starts at 10GHz or the like. So, you need a VHF/UHF SSB rig.

And then there’s the antenna.

Antenna

There are three options when it comes to antennas: huge, big, and modest. Huge VHF/UHF antennas are for Americans and others with acres of land. They are typically 48 or more stacked and bayed Yagis. Since you must point at the Moon, you can imagine the mechanics and electronics to automatically rotate and elevate 48 Yagis. Radio amateurs with huge antennas are the heavy lifters of the moonbounce world. Without them, novices wouldn’t get off the ground.

The 432MHz array – Frank Potts, NC1I. At https://www.qrz.com/db/NC1I

Then there’s big. ‘Big’ describes folk like me who put up four or more Yagis. That’s easily done. It’s all standard kit. My antennas are on a five-metre scaffold pole. Yaesu and others make az/el rotators, and at VHF/UHF the feeder doesn’t cost a mortgage. Automatic Moon tracking can be done on an Arduino or the like. And many folk in this bracket run 500W.

4-Yagi array at GM8JBJ at https://www.qrz.com/db/GM8JBJ

Finally, there’s modest. There’s a whole movement of folk who use single Yagis and a barefoot rig. And many of those use a lightweight long Yagi mounted on a homebrew tripod. The advantage of this is that you can also avoid spending on a rotator, or on a low noise pre-amp (since you’ll be close to the Yagi feed point). These simple systems are often used /P from some piece of open high ground.

Single antenna portable EME operation at https://www.hamradio.me/operating-tips/eme-on-a-budget-part-2.html

Personal Qualities

There are two. Belief (that you can do it). And patience.

It also helps if you do a lot of research to optimise your kit.

Results

The software does everything for you. But you must do the research to know when is best to try.

Conclusion

The truth is that Moonbounce is not that easy. There are several propagation mechanisms that will thwart your attempts.

First, there’s Faraday rotation. The polarisation of the transmitted wave is sometimes distorted along the path. And there’s nothing you can do about it – save use rotatable antennas, and that’s hugely complex.

Then there’s libration fading. The Moon wobbles. And sometimes the reflected waves received back on Earth create an interference pattern in time with deep fades. There’s nothing you can do but wait till the effect stops.

And of course, it’s stupid to try when the Moon and Sun are both within your antenna’s beam. The Sun adds noise to a sensitive system. But you can just wait till the Moon is on its own.

And then there’s the little issue of few folk listening at any point in time. But you can always arrange a sked on a chat room.

None of these issues diminish its street cred. They even enhance it because they make it complicated.

But here’s the secret. Given the simplicity of the kit, anyone can do it.

Links

More detail from John Berry GM8JBJ https://hamradio.engineering/moonbounce-eme/
John Berry QRZ page https://www.qrz.com/db/GM8JBJ
NC1I QRZ page https://www.qrz.com/db/NC1I
HamRadio.me EME on a Budget https://www.hamradio.me/operating-tips/eme-on-a-budget-part-2.html
WSJT-X Digimode Software https://wsjt.sourceforge.io/