The LSWC 2018 Construction Contest

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Dec 042018

Wednesday 21st saw the LSWC hold their annual Construction Contest for the Joe Rose Memorial Trophy. Last year saw us two different versions of ATV transmitter. One being for home use including a partly assembled water cooled power amplifier (For an update see below) built by Adrian M0NWK. The second, and also the winner for last year, being a fully portable transceiver in a case built by Jason G7KWP.

Adrian M0NWK

This year Started off with a similar theme. Adrian M0NWK, started off by showing us his Arduino powered controller for a comtech 23cm ATV transmitter.

This was achieved by removing the dip switches from the transmitter and replacing them with a SSR (Solid State Relay) board. These relays are then controlled by the Arduino which also shows the selected frequency on the front LCD.

Adrian also showed us the completed Water Cooled Power Amplifier which was shown the previous year. Also shown was an Arduino controlled Temperature monitor.

Andy G0FVI

Next up was Andy G0FVI. Who has constructed an 80m CW receiver which will eventually become a transceiver in time. By choosing an IF of around 10.695 this allowed him to use bits from numerous scrap 11m radios he had laying around.

The bandpass filter was fabricated from two Toko type ferrite core coils.
The first mixer is based around an SA612 chip and also provides amplification. In retrospect this may have been a bad idea as the chip does produce a few ‘birdies’ although they are well below main signal level.
The VFO is an Alan Lake design for 80m with the L/C of the tuned circuit changed to give an output of 7.2-7.1 MHz. Output is buffered in the VFO enclosure and this is fed to the 1^st mixer.
Output of the 1^st mixer is fed to a 10.7 MHz XTAL filter with a bandwidth of about 15-20KHz.
The IF amp is based around an MC1350 IC. Negative DC feedback from following stages provide AGC action (fast/slow).
Demodualtion to provide audio out is achieved using a diode ring mixer. Such a mixer provides a nice clean output with little spurious signals. A 10.695 MHz signal is fed into the ring mixer (together with IF).
Demodulated audio is fed to a 2 transistor pre-amp which also provides DC feedback for AGC. Audio is sampled at this stage and fed to another transistor amp to drive the signal meter (taken from an 11m walkie talkie!).
The audio stage is based on a rather ancient LM380N!

All stages were built and tested using a sig gen/scope etc. before being connected. Great care was taken with the construction of the VFO, whose spectral purity I was finally able to look at using an SDRplay RSP1A and a beta release spectrum analyser app.

Controls are IF (RF) gain, volume, RIT, AGC fast/slow and VFO.

When I complete this I will add a prefabricated board for PA and some TX/RX switching (should just about fit). I will sample VFO and mix with TX XTAL oscillator, add some filtering and off to PA. Might be an idea to have a go at matching XTAL filter in the receiver too.

David G6MAF

Next up was David G6MAF. Who had constructed a RF tap, or signal monitor which covered 2-30MHz. A device like this is very useful for monitoring your own transmissions by connecting straight into the feed line. With 50 ohms through to the antenna from the transmitter, a second output is taken and attenuated for feeding into a device such as a spectrum analyser etc…

Bob G4PDF

For the final item we made full circle as Bob, G4PDF, showed off his portable 5GHz ATV Transceiver. The equipment was all installed in a box which was mounted to the back of the dish which was then fixed to a tri-pod. The transceiver included a screen overlay showing his Callsign and also converted a received GPS signal into a locator which is also displayed.

The Winner

It was at this point after all had builds had been shown that contestants left the room for the remaining to vote on who’s they thought was the best. After discussions about complexity, imagination, modules or scratch built & uniqueness, the vote was in.

The contestants were called back in and the Winner was…… Bob G4PDF, with his 5GHz ATV.

The trophy will be awarded at the clubs AGM.

VHF National Field Day

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Jul 142018

Last weekend, 7th-8th July, the club put on a station for VHF National Field Day.

The intention of this weekend was to have a social weekend for all members and to allow those who have not participated in a contest, me being one of them, to try things out in a relaxed and chilled manor.

Setting up G5FZ/P

After Preparing equipment on the Wednesday before, Les G1LQB, Stephen 2E0SSM, Alistair M0TEF & Steve M5ZZZ were down early on the Saturday morning to load up the equipment.

Once ready, the team headed up to the old RAF Scampton bomb dump where most of them would be stationed for the remainder of the weekend.

Fitting Antennas to the mast

On Arrival we were soon joined by Fred G4HNQ & Peter 2E0FGA. The first task was to get the antennas mounted on the mast and the mast winched up into position. One thing that should’ve been done before raising the mast would have been to test the rotator. Unfortunately we all forgot until the station was set up, only to find the controller we brought didn’t work. Fortunately, with the shack only being a few minutes away, Stephen rushed back to search for another one. Returning a few minutes later with a replacement and the station was ready for TX testing. It was found that the log-periodic that was brought gave a high SWR on all bands and it was suspected the Coax to be at fault as it had not been used for a while. The 2/70 beam however worked perfectly.

Les Setting up the Camp

The Portable station for the weekend

The setup team, minus me behind the camera

Time for Operating

After a few QSO’s were made to test the setup all was ready for the Contest to start.

The contest soon got underway with various people taking the hot seat in front of the radio.

As the day progressed the contacts started to come in and as the conditions improved one contact was made with a distance of 700km on 2m. Who says the 2m band is for local contacts only?

As the sun set the radio was kept in use until late into the evening. It was at this time that Stephen & Peter had to head home leaving Alistair and Les to man the night shift.

After some sleep in cars and tents Pam G4STO stopped by to provide breakfast. before heading off. Switching on the radio Alistair heard a station calling DA0FF. After checking the logging software to find we hadn’t had them before he started calling back. After battling the conditions the QSO was completed at a grand total of 786km. During the morning Fred G4HNQ returned and helped pack away.

Throughout the weekend there was a constant battle against the flies and bugs especially while we packed up on the Sunday.

After getting the equipment back to the shack everyone headed home worn out and sleepy from the enjoyable weekend.

The Grand Total at the end of the weekend was:

2m, 62 Contacts with a total of 21,675 points.

70cm, 15 Contacts with a total of 4,408 point.

The log submission deadline is in a few days so we will have to wait and see where we end up in the tables.

2m QSO Map

70cm QSO Map

With Such a successful weekend the club intends to put on more events like this in the future so keep your eyes pealed.

RDXC 2013…..

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Mar 222013

Saturday 15th March brought about one of my personal favourites in the contest calendar ,this along with ARRL DX are in my opinion more fun…As we will see things nearly went to plan apart from the huge CME that was as the contest started hurtling its way towards good old planet earth… ‘thanks for that Sol’!!

Well, things started off great with the blocking of the frequency we intended to use at start of the contest . I started calling a general CQ at 11:00z beaming Russia 50 degrees ish and this is where the fun began. First caller in the bag a YV (Venezuala) on the back of beam, glowing report recieved I reversed the beam to beam him +30-40 over was reply ‘good’ I thought ‘bands in cracking shape’. Next caller in was a nice gentleman driving the length of Florida going home for the weekend as I rotated to him my report from him was I was endstopping him, he was +30 to G5FZ so far so good. Steve took over to continue blocking as the clock was ticking nosebag to be had and tea to be made before kick off …….now in my humble opinion just before a CME lands the bands seem to become ‘wide open’ whether i will be stood corrected I don’t know but every time a coronal mass ejection is 12hrs or so out good dx is to be had for hardly any effort or RF output and please don’t ask why this is just my experience as a humble op lol !!

In RDXC the rules are simple work everyone but the more Oblasts (postcodes) you work of Russia the bigger the mult. Working Russia gives 10pts +any oblast mult,a qso with your own country 2pts,a qso with a different country but on your continent 3pts and a qso with another continent (ie Stateside) 5pts….And the contest lasts 24 hrs no long haul this time !

We kicked off at 12:00z with myself on the mic, and as some of you know, if its slow i get bored and fed up quickly so Steve(M5ZZZ) took over and was more relaxed than I’d ever seen on a mic !! With a nice and steady start I made the decision to move band to 15m as qso rate was good but not excellent which we did with some good results , peaking in the first hour with 117qso which cant be sniffed at.Mark (M0ZLE)arrived at just before 14:00z with Steve leaving as himself and I where going to be pulling a late one ….Staying on 15m was producing results as you can see. While working an OH(Finnish) station the whole band blacked out +30-40 of noise he kindly waited to finish exchange but it was an ominous reminder of what was on its way !!

RDXC2013 ………. Notice How Flat Sunday Is !!!

We remained on 15m until it was felt we had wrung the band dry at roughly 17:00z we moved on to 40m which some might say suicidal , thats too early i hear you scream in droves, maybe, but this is where the fun begins. Russia is 3hrs ahead and already in darkness working JA, VK, etc the move payed off ,then Mark left as Steve had duly arrived for our late shift ! . I left Steve to nip to local kebab emporium for a tasty snack to bring back to Aisthorpe…

When I arrived back we had a visit from Pam (G4STO) who sat with us for a bit and watched me demolish said mixed kebab ! Around this time 40m was starting to get overfull with people setting up on us and calling which is normal for a contest but really peeves me off !The decision was made to now jump up to 20m as we was entering grey line and I felt we could run a bunch of stateside for an hour or two…

The move payed off for the first hour but the band was dying earlier than of late and we moved reluctantly back to 40m about 22:30z but finding a ‘home’ was difficult, and the run rate was very poor ,plus the qrm was appalling +20 with all the bells and whistles on !! Stateside had at this time just, just, just started to open working my friend Walt K1QS. A special mention for Walt K1QuiteSexy as he managed to work us on every band we run on and as always a cracking signal !! Appreciated, thanks buddy !! We surrendered at 23.20z as Steve was having to go and I knew that I wouldn’t last all night, so we left with a heavy heart knowing full well that the bands would be poor the following day….

I arrived at shack at 6:00z on the Sunday and firstly checked progress of CME which landed at 06:01 that morning and I hesitantly turned on my trusty steed , cursing myself for going home to my warm bed . My curses increased as I monitored 20m and normally strong stations where very weak and the band reports where far from rosy !!

A quick cup of tea and biscuits later and off we went for a second day which was that slow I had to fight myself nodding off , luckily Steve turned up at 8:00z and we started swapping knowing full well we had to run 20m and 10m to collect the mults. We continued to soldier on and at 11:00z dropped onto 10m to see if there was life and much to my amazement there was but working them was hard labour best dx on 10m was HS0ZIN who said he would be thankful when 12:00z came!! He was our second to last caller as sitting and cq’ing was getting nowhere and we had searched and pounced all we could pulling the plug at 11:46z .

Overall a good result working 978 stations 140 Oblast and 128 Dxc for an overall score of 1,598,084 operating for a total of just over 16hrs a good effort overall we bettered our score from last year which was 443 qso for 362,780 , if before the contest knowing the cme was on its way and you had asked me what I would be happy with I would of answered 1,000 qso. I wasn’t far wrong and yes I am still cursing our luck.!! !

Thanks to my operators Steve and Mark for your time !

Footnote: Walt K1QS will be operating in CQWPX 30&31 March , so keep your ears out for him on 15m !!

Best 73’s Sy M0SIY

ARRL DX PHONE CONTEST 2013……

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Mar 192013

2nd and 3rd of March 2013 saw the annual ARRL DX 48hr Contest. This contest is maybe one of the easier contests in respect that we can only work Stateside/Canadian stations. Basically point beam to 300 degrees and call !!

ARRL DX 2013 Final Score !!

I decided due to lack of operators to limit our involvement much the same as last year trying to optimise running time during daylight instead of cramming onto 40m in the night with most stations working splits ie. listening above 7.200 and operating below as you know states have a higher 40m band plan, it is allowed to receive on lets say 7.210 and call on 7.180.

Anyways back to the crux of the matter, so i tried to run much the same as last year when we ran with just myself and Jeremie which was productive always busy running when we was operating, culminating in 1st in UK, 16th in Europe and 29th in world for 16 hours operating!!

We kicked off on Saturday about 10:30z starting on 20m as you can see from picture things were steady most of States still in bed hi hi !!, and propagation a bit flat .Also we had our friend Murphy in shack as pc kept muting the auto voice keyer!! Mark (m0zle) and I managed to sort it while I was doing cartwheels around shack…Steve (m5zzz) took over but had to leave as did Mark at just before 13:00z . At this time i switched to 15m for a marathon run which would last for nearly 5 hours at mic, during first hour I worked 122 stations the pile up was nice and steady ebbing and flowing, if at peak of flow it had carried on during 13-14:00z I peaked at 260 qso an hour average on run rate but unfortunately it didn’t continue hence 122 qso much to Sys’ disappointment!!

Steve then took the reigns at just after 17:00z for his ‘Jedi’ training with me resting voice and a much-needed comfort stop !! Dropping back down to 20m to try to achieve some more multipliers (each state/province is a mult) saw rate drop but not to unacceptable levels so we carried on until about 20:00z then switched to 40m due to a technical hitch which was out of our hands ……We stopped not long after just as 40m started to open but problems persisted so we sacked it feeling very frustrated !

On the Sunday I started about 09:45z on 20m and we stayed on 20m all day to pick up more mults and hopefully to get a nice run rate as we had worked a lot of stations on 15m the previous day…Run rate was steady to say the least with Steve arriving to help at 12:00z after his news-reading.Steve unfortunately had to go again so it was up to myself to perform …Our second biggest peak run occurred at 15-16:00z with 110 being worked in the hour then things started to slow up just a bit but was ready to work into the night with the dreaded drop down to 40m !! Unfortunately this was not to be as problems out of my control scuppered this and had to surrender my pile up at 17:30z ….Hopefully since, this the problem will not occur again !

Overall a very productive weekend taking into account limited running time hopefully it will be enough to successfully defend our 1st in U.K. place from last year. We worked more stations than last year 1062 last year 1200 qso this…378,777 points last year 406,461 this…. 12hrs 47m operating last year compared to 17 hrs 7m this !!!

My thanks go to Steve for giving me quite a bit of time and patiently listening to my advice I gave resulting in a more relaxed operator in chair and a higher run rate for himself !! Well done mate, you are truly on your way to becoming a Jedi master !!

I hope you enjoyed my first attempt at being an author any comments are welcomed !!

Best 73 de Sy M0SIY