RSGB May 144MHz Contest.

Once again the nomadic Invicta Contest group was very kindly hosted by the Bredhurst Amateur Radio Transmitting Society (BRATS). The BRATS are very fortunate to have a compact but very well-appointed clubhouse & shack with a large field at the rear of a pub high above Medway just off the M2. Thank you, BRATS.

The Invicta Contest Group (ICG) is a loose affiliation of Kent (& out of county amateurs) who wish to participate in VHF & up contesting. We tend to participate in the larger weekend contests. Ian Hope, M5IJH provides high power, legal limit, kit along with various arrays & the means of putting them high in the air. Stuff which most of us could not install or use in our average gardens surrounded by neighbours.

The ICG is a group in addition to & not instead of local clubs, many of whom do not or cannot support VHF contesting. ICG works with local clubs (like BRATS), has supported them with kit at their events or to demo the QRO kit. Whilst we are a contest group & want to do as well as we can in each contest we are not ‘rabid’ in our approach. We are very content to introduce the novice into operating & don’t mind sacrificing the contact rate to give a newcomer of the returning ham the experience of working a contest. Obviously, we have to work within with licencing conditions as well as contest rules, but they are our only hard limits on who operates.

The May 144MHz contest is one of the first ‘big’ weekend contests & with the weather starting to warm up is usually well supported. This year the ICG decided to run a ‘proper’ weekend event. That means the trailer tent to provide the shack, kitchen & sleeping accommodation along with two arrays.

The arrays chosen this time were as below to give us best coverage but manageable with the limited manpower to build & hoist them.

The first array is a pair of 9ele LFA Yagi vertically stacked, put up on a SCAM pump up 12m mast. This array is used as the DX hunter & is fitted above a rotator. This array allows us to focus in on weak signal stations not resolved by or covered the parts of the compass by array two.

The second array is four 3ele LFA Yagi, also vertically stacked, again on a SCAM 12m mast. This array is the ‘UK workhorse’ fixed roughly NW to point up the spine of the country with enough beamwidth to reach out to as low as South Wales across to Essex & with enough gain to hear most of the stations in the southern part of Scotland. The Isle of Man & Ireland are often worked on this array & most stations in the Southeast can usually be worked ‘off the back of the beam’.

Both arrays have a mast head box that contains a relay that switches between the RX & TX feeders. A low noise preamp along with a chosen attenuator to control the amount of gain & bandpass filter are in the RX line.

The station this time consisted of an Icom 7400 on 14MHz driving a Q5 transverter with split RX TX outputs. The TX output is then amplified by a valve amplifier that is adjusted to deliver up to legal limit power at each array via a splitter. Both arrays are driven at the same time. The RX side is chosen via a switch at the operating position. Logging is on a laptop using Minos with a combined database of previous contest contacts to provide an immediate lookup table when data is entered into the log. An entered callsign immediately shows previous locators & bearings from our position, greatly assisting in pointing the beams. If a locator is entered, it shows previous callsigns logged from that square helpfully assisting identifying a potential contact this time. Obviously, these are only an aid & should not be relied on as confirmation of required exchange information. ICG is a prime example, we operate from different sites & so don’t use the same locator each contest, also depending upon the contest we may use a different callsign from a previous contest at the same site.

Saturday morning was thankfully warm & dry which allowed for a quick deployment of the trailer tent, the shelter which permits everything else to happen. Whilst I left Ian & the BRATS members to place out & put up the very heavy SCAM masts, I concentrated on building the 9ele array aided by Paul, G0ILO, running out the two feeders & control cable ready for checking then putting it the mast. This is where we hit our first problem of the weekend. Once all was assembled on the SCAM we attempted to pump up the mast, the mast hardly budged & checks revealed an air leak in the top section. This is often caused by a dry seal, so a very light smear of silicon grease was applied & the section manually lifted & dropped to lubricate the section. Sadly, all to no avail, so the mast sections were manually pushed up & locked off. Hard & slow work for Ian.

This time-consuming process absorbed nearly all the time left before the start of the contest at 1400UTC, so I left the rest to complete the build of the second array whilst I prepared the operating position & started the contest.

The start of the contest was a steady affair calling CQ getting a trickle of contacts rarely getting a run of more than two at a time, that said many of those were very satisfying working a good number of Scottish stations & more Irish stations than usual. As the first hour concluded a very brief interlude was taken as Ian plumbed in the second array & we were fully operational. I hogged the mic for the best part of the next hour to allow the labourers to rest, make a brew & gratefully cook the first bacon bap of the weekend. Fortified I passed the mic on to Paul, G0ILO & later Ian, M5IJH. The three of us then taking about an hour or so in the chair in rotation.

Fairly quickly I noticed that the usual roar of European stations wasn’t present & even when pointing East, we weren’t picking off the usual string of German stations along with the ever-present Dutch & Belgians. When I commented, Ian reminded me that the European contest was no longer coordinated with this one but with the VHF & UHF one earlier in the month. This certainly had an impact upon my operating tactics, spending more time with the 2×9 array pointing SW or N rather than sweeping across Europe. The lack of EU Stations certainly affected our contact rate & it will be interesting to see how well supported the contest was by UK Stations compared to past years. The lack of runs of contacts responding to our CQ calls led to more sessions of ‘search & pounce’ but again in these sessions most stations heard were already in the log. It was certainly one of the hardest contests I can recall gaining contacts for the efforts made.

Saturday petered out at about midnight local time after getting only a couple of contacts over the last hour. All the BRATS members had retreated home hours before & Paul who had pitched his own tent to camp overnight had decided to return home for a warmer bed. The benefit of a nice settled high pressure zone giving a clear, bright, dry & warm day led to a noticeable drop in temperature once the sun had set, resulting in a chilly evening & night. I had packed a buffalo shirt as a just in case but was pleased I did as it kept me operating in comfort. I was also pleased I had grabbed my four-season sleeping bag rather than the summer job, so had a warm comfortable night’s sleep, well until 5am local. My alarm clock was my little Jack Russel dog, Maddie who was in her portable kennel under my sleep pod in the trailer tent. I thought it was the call of nature causing her whine, but I soon realised as I released her it had been the local rabbit population who had started to graze adjacent to the tent. A flurry of cotton tails exploded in all directions towards the hedges as we emerged.

So being up & awake it was back to the operating chair, an initial tune high to low & back again resulted in only hearing one QSO in progress, both stations previously worked. So, with the amplifier fully powered after being left on idle to keep the damp off the tubes the keyer was again fired up. It took nearly an hour before the first contacts started to trickle in. But fortified by first, second (Third?) breakfast bacon baps & my two-pint insulated tea mug the log was steadily filled with contacts, but not at the rate we would really like! The mix of contesters & the Sunday morning casuals who had fired up the rig to find the band full (!) of signals & joining in to give a point away is always enjoyable. We even got a few more EU stations coming on to liven the mix.

We were looking forward to the Backpackers coming on air at 1100UTC to add a fresh source of contacts. Either the hills were sparsely occupied this time or we were unlucky in attracting responses as the contact rate remained fairly slow when calling & it was hard to find new ‘stroke P’ stations when we went search & pounce.

At the contest end we agreed we had enjoyed ourselves; the kit had worked (well the defects hadn’t stopped us!), the lack of EU station was disappointing & something to be considered in our planning for next time & the weather had been kind. A good contest. Now to dismantle.

The beams were rotated to the right direction to lower them & then power cut to the station. The first array to be dismantled was the 2×9, the mast lowered with ease. But then came a realisation that we were short of help, we were just the three (two able & me semi-capable) & lacked the BRATS who had helped with muscle to lift the heavy SCAM with the array from its rest to vertical. A quick brainstorm between the three of us formed a plan of action. Ian& Paul successfully removed the stub mast out of the top of the SCAM & lowered the array to the ground without dropping it or spearing me below in the process. It was then that we noticed what had been a potentially serious problem. The lower rotator clamp to the stub mast had cracked, surely if the wind had blown any harder over the past 24 hours it would have toppled. Luck had been with us this time.

The same process was successfully applied to the second array without incident. It was then just a steady process of dismantling & packing all the kit down under Ian’s supervision into & on the trailer tent as well as his car which does a fantastic impression of ‘the Tardis’ as it swallows kit that it couldn’t possibly fit.

I quick walk of the area of the field to check for litter or other small dropped items was the final task after locking up the BRATS shack & driving home.

Later in the evening Ian messaged the map of our submitted log as well as a photo of the fault on the SCAM, a spacer collar had cracked & as a result of its failure it had shredded the seal. Annoying but readily repairable. The cracked rotator clamp will be replaced, but discussion on merits of this lightweight but vulnerable solution over a safer but heavier rotator cage will be rehashed. We are already discussing nested arrays on the same mast to have fixed but switchable coverage over our main target directions & possibly a lighter rotatable array. All stuff to keep the conversation going between contests.

Again, thanks to BRATS for being such good hosts, to the amateurs who visited the station. Especial thanks to Ian, M5IJH who provides & builds the kit, operates, as well as cooks the necessary bacon baps which fuel this operator. Finally, Paul, G0ILO who provided great company, conversation & most importantly a share of the operating.

ICG https://invictacg.weebly.com/

BRATS https://brats-qth.org

MINOS https://minos.sourceforge.net

73,

Ian, G0PDZ – AG5XD