G4WSM Field Day

Browsing the website of the Weston super Mare club (G4WSM), I found the video below. ¬†As its rather fun, I’m posting it here too ūüôā ¬†Whilst we’ve just had our field weekend wouldn’t it have been good to make a video like this? ¬†Unfortunately, the sound is a bit corrupted with funny ‘dit and dah’ noises. ¬†Only kidding ūüėČ

Andrew 
G0RVM

Antenna Maintanance

Yesterday myself, Andrew, Graham, Rex, John and John spent the day at the Chantry renovating the club’s antenna systems.

Our plan for the day was to inspect the existing antenna systems, replace a section of coax between the attic and balun and to install and tune the new 40m dipole.

Condition of existing antenna systems

Existing 40m dipole balun

Existing 40m dipole balun

The overall condition of the existing HF antenna was good, but clearly the self-amalgamating tape has suffered from UV degradation. This doesn’t appear to be a major problem however the antenna has only been up roughly 4 years, so the problem would get worse over time.

A photo of the existing co-linear VHF antenna

Existing VHF Co-linear

While on the roof we also inspected the existing VHF antenna. It is clear that it is not ideally placed, being blocked by the chimney stack as well as the Chantry’s satellite dish.

Replacing the coaxial cable

One of the jobs for the day was to replace the RG-58 coax run between the attic space and the existing balun with some superior Westflex 103. In order to do this, Andrew and myself had to climb into the attic in order to cut the existing cable and solder new UHF connectors onto it. This allowed us to replace the cable between the attic and the antenna. On completion we measured the loss through the cable using a 50ő© dummy load and power meter.

new cable run

New Westflex 103 cable run

We measured the loss at just under 3dB at 7mHz. We measured 60W at the end of the cable with a 100W input. Currently we plan to improve this loss further by replacing the rest of the cable to the shack

Andrew holding a dummy load and power meter

Andrew getting ready to test the loss through the new cable

Installing and tuning the new 40m dipole

With the new coax installed, we now set to work installing the new antenna. Before we could putt the new dipole in place we had to let down the existing antenna. As the two ends were attached to trees, I volunteered to put my tree-climbing skills to use and lower the existing elements

Rex at the foot of a ladder

Rex giving us a hand getting up the trees

With the antenna on the ground we attached the new dipole and hoisted it into the air. Following some tests with Andrew’s MFJ antenna analyser we deduced that the elements were too long. Following several rounds of tuning we reached a state where everyone was happy with the performance of the antenna.

New 40m dipole balun

New balun installed

We sealed the connections with self amalgamating tape and headed to the shack to have a listen to the band.

40m dipole

 

Performance

Frequency (mHz) Resistance (ő©) Reactance¬†(ő©) SWR
7.0 60 8 1.2
7.1 78 0
7.2 112 0 1.5

We also tested the SWR in the shack and measured an SWR of 1.4 at 7.2mHz. A quick sweep of the band picked up some loud and clear Morse, although this may be due to a contest that was running at the time.

Conclusion

We hope that the new 40m dipole continues to deliver excellent results. There are still improvements that need to be made to the club’s antenna systems, including:

  • Adding the two other elements (30m and 20m) to the fan dipole array
  • Replacing the coax run between the attic and the shack with lower loss cable
  • Deciding on an effective way to relocate and improve the VHF antenna system.

I’d like to thank Andrew G0RVM, Graham, Rex G4RAE, John M3EQQ and John M0HFH for giving up their time yesterday to help the club. I had a great day and learned a lot throughout the process.

Peter Barnes
2E0UAR

Electromagnetic Field 2016

As some of you may be aware, last weekend I went to Guildford to attend this year’s EMF camp. Electromagnetic Field is a camping festival geared towards hackers and makers. The weekend is filled with interesting talks, demonstrations and crazy projects.EMF Sign

Arriving on Camp

Car

My idea of a camping trip!

I arrived on site with a reasonable idea of what to expect, but this was reinforced when someone whizzed past me in a Sinclair C5. This turned out to be only a taster of what was to come.

I was to be joining a group of amateur radio enthusiasts who were running the EMF hams village. There were 16 of us and we had all come with a variety of equipment. Using the special event callsign GB4EMF, we operated using the following stations:

  • HF Station – Yaesu FT-1000, Mosley Mini-33-aw beam,¬†SCAM-12 mast
  • VHF/UHF Station –¬†Icom 706,¬†2/70 Beam, telescopic mast
  • Satellite Station –¬†Yaesu FT-847,¬†2 & 70 ZL Specials on G-5500 Az/El rotator, tripod
  • Local Comms – Crossband repeater, Yaesu¬†FT8900, X-50, 5.4m Clansman mast

EMFhams Setup

This was all made easier by the network of datenklos (data-toilets). These were power and networks hubs being kept dry using porta-loos. Over the weekend we maxed out at over 100kW pulled off two generators, 66  Wi-Fi access points, 4500 networked devices and 3.5TB of data going between our network and the internet.

 

Things to see

There was a lot of ‘stuff’ at EMF this year. A few honourable mentions go to the high altitude ballooning village, fire pong, just add sharks laser cutters, blacksmithing tent, lockpicking tent¬†giant guitar hero, the music powered quadruple flamethrower,¬†retro arcade tent¬†and the amateur radio village of course.

JustAddSharks Laser Cutter

HABville's weather balloon tracking station

HABville’s weather balloon tracking station

Pub sign!

Pub sign!

Overall EMF camp this year was a fantastic event, full of technology and ideas. The talks I attended were very interesting, and all available of the EMF Youtube¬†account. I’m definitely signing up for the event when it next runs in 2018. For more info see emfcamp.org, wiki.emfcamp.org, and for more photos see¬†https://www.flickr.com/groups/emfcamp/pool/.

View of site

PS: I’ve got my new callsign,¬†2E0UAR

 

-Peter Barnes (M6KVA, 2E0UAR)

Field weekend

Derek, Mark, Andy and Rob fitting the hexbeam to the towerFriday 29th April saw the start of the TSGARC big Field Weekend. OK, not quite the same as its¬†BBC Radio 1 namesake but just as much fun ūüôā ¬†Setup took place¬†on the Friday and was finished by late afternoon – much quicker and more smoothly than last year. ¬†The event ran over the following Saturday, Sunday and everything was dismantled and removed by mid-Monday afternoon.

So a big thanks to those that came and who helped setup and/or remove everything. ¬†An event like this was¬†only possible thanks to some accommodating¬†friends of John, M6EQQ who allowed us to use their field. ¬†As a thank you the club bought them a bouquet of flowers and some beer. ¬†I will let you work out who received what! ¬†Like preceding days, the Monday was a relaxed start and the dismantle job only started late morning. ¬†Unfortunately, as some people know only too well it started raining just after lunch which incentivised speedy work. ¬†But some of us got a little damp – Rex ūüėČ

FT-897, TSGARC field weekend 2016Over the whole weekend there where two radio tents, the first used the FT-897 loaned to the club by Derek.  This allowed HF and VHF (6m) operation using a G3TXQ Hexbeam from MW0JZE (top image).  VHF (2m) operation was possible using a 9-element Yagi from Tonna.  The FT-897 PA provided 100w on HF and 50w on 2m.  The highlight of the first day was a solid 17m contact into Japan by Derek using SSB.  But there where also lots of other contacts across the European and American continents.  The hexbeam was observed to have useful directivity mounted at 12m atop the trailer tower.

John, M0HFH working Morse code on 14MHzThe second tent used a home-brew HF (20m) Bobtail Рorientated to provide East/West lobes Рand a 3-element Yagi for 2m, both courtesy of John M0HFH.    This tent used the clubs FT-450 both for SSB and CW plus an FT-857 and FT-817 provided by John and Rex.  The tent also showed rebellious tendencies, opting at times, to use some rather exotic batteries which no-one wanted to be anywhere near!!  Thanks John!

There, was of course, another tent, a very important tent and one where people congregated. ¬†The ‘brew tent’ was where we had the stove, tea, coffee and what seemed like an endless supply of bacon – thanks Jane – plus copious amounts of biscuits ūüôā ¬†The weather was mostly dry but a little on the chilly side so this was indeed a popular tent.

In total we had two big (6m x 4m) tents, the rebellious tent (2.5m sq) plus a small day tent to keep the generator dry.  These provided ample space and shelter for the weekend.  The final accommodation to mention was the chemical toilet, arguably the most important item to making the field weekend possible.

TSGARC Members at work!Everyone who went had a good time and all the equipment worked well. ¬†Simultaneous operation of two HF stations was not really possible, or expected, due to the proximity of the antenna’s so perhaps a project for next time¬†is to make band-pass filters. ¬†It was a surprise to find¬†¬†that even HF low power transmissions broke through on the other tents VHF (2m) activity.

With only two radio’s in operation at any time it was common to find people in the ‘Brew tent’ or contributing to activities in the field. ¬†In the above image John, M0HFH is being helped¬†to connect an ATU to the feed point of the HF (20m) Bobtail.

Mark helping John fit an aluminium section to the top of a fibreglass mast.There was also some genuine help.  Many hands made light work of jobs including raising the tents and preparing the operating positions.  Unpacking, assembling and raising the hex beam was made easy with great support.  Thanks also to Ron, who stuck it out in the rain on Monday to methodically dismantle the hextbeam such that it can be easily reassembled next time.

Personally, I’m already looking forward to another event next year. ¬†But we may move the date back to the late May Bank holiday weekend as the weather should be a little warmer ūüôā

Andrew
G0RVM

Propagation forecast tools

Many thanks to Peter (and his able assistants) for the¬†informative presentation¬†on ‘Propagation Forecasts’ this past Wednesday, I found it fascinating and very useful.

On a related note I happened to stumble across the following news on the RSGB website:

The RSGB Propagation Studies Committee has begun work on a new web HF propagation prediction service. It will feature both area coverage predictions as well as point-to-point on-demand predictions. Presently, only area coverage has been completed and this can be seen at www.predtest.uk. This will soon be followed by the P2P predictions. It is planned that following these trials the RSGB website will host the predictions. Comments and suggestions are invited by Gwyn Williams, G4FKH via email to g4fkh@sky.com.

The site itself (screenshot at the top of this post) also mentions that the Python source code behind the new tool is open source and available on GitHub.

Please share your own¬†propagation tools with us¬†in the comments below ūüôā

Museums on the Air

Over the last two weeks the TSGARC has provided Equipment and personnel to put the Thornbury and District Museum on the Air.

The event was widely supported by Members, the Museum and even the Press.

The Log Sheets can be viewed by clicking Here.

Two main stations were used both using the Callsign GB4TDM. The majority of contacts were made using VHF 2M with a number of CW and a single SSB contact being made with HF.

Field weekend (3)

TSGARC Field WeekendThis is the third post in a three part series regarding the late May field weekend of the Thornbury and South Gloucestershire Amateur Radio Club (TSGARC).

So Tuesday arrived.  Four days on site had passed very quickly.  The final day was set aside for taking everything down, packing it away, clearing the site and getting home.  No radio operation was planned. This proved a good choice as it was mid-afternoon when John finally left.

Just like the setup day, we had a good attendance and it didn’t take long for the tents to come down and packing to start. ¬†What took time was all the little things like tables, chairs, food etc not to mention the coax, antenna masts and guys… ¬†Anyway, by mid-afternoon everything was packed and the only evidence we had been there was the trampled grass. ūüôā

TSGARC Radio TentThe objective of the weekend was not just to setup a station and make contacts but to try things that we could not try at home where space or equipment are constraining factors and to facilitate the exchange of skills and knowledge between club members.  Measured against these objectives, the weekend was a great success.  Everyone who attended had a good time and the English bank holiday weather was kind to us.

The club was active on 2m, 6m, 12m, 15m, 17m, 20m and 80m making contacts around the world. ¬†In total we spoke to 19 countries excluding the UK. ¬†We did not generally participate in ‘rubber stamp’ contacts, most lasted several minutes, some significantly longer. ¬†The countries worked were:

  • America
  • Argentina
  • Aruba
  • Austria
  • Bulgaria
  • Canada
  • Israel
  • Japan
  • Kenya
  • Kuwait
  • Russia
  • Spain
  • St. Helena Is
  • Svalbard
  • Sweden
  • Turkey (maritime mobile)
  • Ukraine
  • United Arab Emirates
  • Uzbekistan

The event had 2 x 2kW and 2 x 1kW petrol generators.  The intention was to operate 1 or 2 of the 2kW units and the others would be used in case of failure.  As it turned out one of the 2kW units failed but the other worked flawlessly so no others were needed.  But just having one of the primary generators fail proved how important it was to have backups.  The amount of petrol consumed was surprisingly low (approx. 40 litres) considering almost full day/evening use.

Almost everything went well but things of special note are:

  • site access incl parking
  • the site location was close to home
  • excellent member turnout, especially on setup and tear-down days
  • the chemical toilet
  • separating the radio tent and social/domestic tent
  • trailer tower
  • G-600RC rotator.

TSGARC Catering/Domestic TentOf course there were some things that didn’t go to plan or that could be done better¬†next time:

  • catering – bring your own food & drink failed
  • conversations still occurred in the radio tent and were hard to limit
  • disappointingly low¬†use of VHF despite having some excellent antennas
  • failure of a primary¬†generator.

As organiser of this event I would like to express my special thanks to the following:

  • John’s friends for the use of their field (We have bought them a bottle of Pernot and some flowers)
  • John Laney for the tents and cooking
  • Graham Clark for petrol
  • Rob Dodson for his TS-2000
  • Shirley for the wood burning stove.

Final thoughts

The message from those who attended was that this sort of event is something the club should do again before the year is out.  We will have a rethink about catering and try something different next time.  Possible options have already been identified, discussed and sound promising.

When we do this next? ¬†Well almost anytime is possible, but there is the RSGB VHF Field Day on the 4th and 5th of July and the RSGB SSB Field day on 5th and 6th September. ¬†We should also not forget the ARRL Field Day on June 27th and 28th….

Andrew
G0RVM

Successful JOTA

This year’s Jamboree on the Air at both Conygres and Woodhouse Park was another resounding success. In addition to members of the club we were also assisted by members of the Gloucester Amateur Radio and Electronics Society (GARES) and Woodhouse Park amateur Radio Club.

Paul, John, James and Garry at JOTA 2014

Paul, John, James and Garry at JOTA 2014

A successful two and a half days saw three stations (HF, VHF and UHF) assembled with CW practice and Flight Radar. A number of contacts were made to UK, European and two American stations. During the weekend a number of Beavers, Cubs, Brownies, Guides and Scouts practiced their Morse and spoke on the radio.

The operating conditions at Conygres having been improved over those last year with a new roof being installed. The catering once again was excellent with 6 Gourmet meals being consumed.

The three stations consisted of two FT-857s connected to a log periodic 70cm antenna and a crossed 5 element Yagi with the HF station being fed into a G5RV. The CW practice station utilised two oscillators and a decoding laptop. The Flight radar station was projected showing the location of aircraft as far afield as Heathrow.

I would personally like to thank all members who attended at both Conygres and Woodhouse Park for their assistance and planning.

Paul
M0ZMB