Blackpool Rally 2011A line up of most of the club stewards who spent a busy day in Blackpool on 10th

April 2011. Several absentees from the photo (Keith G8MKO, Brian HelsdonG6XRE for example) were otherwise engaged on duties elsewhere.

Once again the club played a major role in the organising and running of thebiggest one day rally outside London. Members carried out ticketing, door

duties, steward control and radio talk in. We were blessed with decent weatherconditions and a good time was had by all.

www.warc.org.uk

JOURNAL AUGUST 2011 ISSUE 75

WARRINGTON AMATEUR RADIO CLUB

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One major plus for us this year was the attendance of club member Nick GilesG7GPL who brought his professional photography skills and equipment to bear onthe photographic records of the event. The quality was so high that I had todowngrade them somewhat to send a couple to the RSGB for possible inclusion inthe next yearbook!

Club member Samer Tufail won the Nov-ice Trophy in the Construction Competi-tion with a neatly constructed superhetreceiver and a photo of the presentationshows RSGB President Dave WilsonM0OBW handing over the cup.This magazine was awarded the best clubmagazine shield but truthfully many clubsdon’t have a publication so we usually haveonly to score over the Royal Air ForceAmateur Radio Society’s journal QRV.However as RAFARS is a national clubtheir magazine QRV provides a high stand-ard to compete against.

A beautifully constructed and in-novative loop antenna designedby Dr John Seager G0UCP camefirst in the Construction Competi-tion and attracted so much atten-tion that he was persuaded to givea talk and demonstration of hisloops to the club in late May.We were disappointed at not win-ning the Club Stand Trophywhich went to Fleetwood ARS.Some cynics thought that ourfailure to return the trophy in time

for it to be awarded at the rally counted against us.The Norbreck Hotel has received a makeover and is a little less down at heel thesedays but really does need to get the bacon rolls available earlier in the day for theworkers who start early on that Sunday morning and need the calories.

Ron G0WJX

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Club ContactsChairman Alan Vaughan G8WQE alan-vaughano2.co.ukSecretary Paul Carter G7ODJ paulg7odj@btinternet.comPresident Mike Isherwood G4VSS g4vss@btinternet.comMembership fees toTreasurer Bill Rabbitt G0PZP william.rabbitt@sky.com

ContentsPage Title Author Call Sign1 Blackpool Rally 2011 Ron G0WJX

4 Titan DX Antenna - A Review George G3OGQ

6 Bat Detector Review Chris G7GZB

8 Club BBQ 12th July Ron G0WJX

10 Mediumwave Loop Revival Dave G7RKK

11 Practical Wireless Low Power Contest 2011 Dave G7SKR

13 40 Metre Mini Dipole Jim G3NFB

15 Museums On The Air Ron G0WJX

Anyone wishing to contribute to the magazine should send or give their copy to theeditor Ron, G0WJX preferably in MS Word, .txt format or e-mail.

Club ProgrammeDate Title SpeakerAug 9 Undersea Communications Tom M0MYNAug 16, 23 & 30 to be arranged. Ideas to Steve Myall M1DOT!!Sep 6 Sensor Bouys Vincent M0LCRSep 13 CW Filter, Paul M0XPDSep 20 Software Defined Radio with the

Winradio ExcaliburIan M0BXR

Offers or ideas for talks to the programme coordinator Steve Myall M1DOT

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Titan DX Antenna - A ReviewFor some years now I have had a SteppIR BigIR antenna in my downsized back

garden. It has proved extremely good on 30 to 10 metres (I have never tried iton 6 metres although it is capable). It should be good, its a full quarter wave onevery frequency with no compromises. It does however, in common with ALLvertical antennae (my classical education prevents me from calling the plural ofantenna antennas) need radials and these should be at least 0.1 wavelength long ifthe antenna is ground mounted and 0.25 wavelength long if mounted above ground.Unfortunately my garden is not big enough to cope with radials for 40 metres nomatter how hard I try to fit them in and I have had to resort to an ATU in order tooperate on 40m metres. People who know me well will know that I consider it ameasure of failure that in a permanent location any Ham worth his salt cannot feed50 Ohm antennae into the shack.I therefore decided reluctantly to replacethe SteppIR with an antenna which doesnot require radials. This would seem tocut out any vertical antenna since theymust all work against ground. The ad-verts for the Titan DX caught my eyeand I did a bit of investigating. A longconversation with the manufacturerconvinced me that this antenna does notindeed need radials BUT not because ofsome magic in the design but because itis literally a vertical dipole! It is there-fore fed in the middle.Martin Lynch & Sons are the agents forGAP Antennas (ugh) who manufacturethe Titan DX and the only thing to be-ware of is the cost of carriage whichturns out to be considerably more thanadvertised. They do not update the costin subsequent advertisements so do tryto pin them down! – or they will keepgetting away with it. The problem is the length of the box which is about 10 feetlong. The contents are well packed and complete with quite good erecting and mountinginstructions although the lengthy safety and warning notices which precede theassembly instructions fairly put me in mind of the ‘Elf and safety’ nonsense . Allitems are bolted together with one size of self tapping screws with hexagon headsand there is an excellent nut driver tool provided in the kit. They recommend thatthe antenna is put together on a flat surface at least 30 feet long which I founddifficult to find. Eventually I assembled the antenna in two halves which I then

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joined together. There are no problems in assembling the whole antenna providedthe instructions are followed to the letter. Any problems I encountered were due tomy own ‘big head’ in thinking I knew better than GAP. I did like the provision ofextra screws because (and I quote) “we know how lawns like to eat screws”. Alsothe holes for the screws are in the main duplicated in case (it says) “should youaccidentally strip a hole by over tightening”At the base of the antenna is a counterpoise made up of four 80” aluminium rodswith 16 SWG wire running round the ends, the length of which can be varied toachieve resonance on 40 metres. This is actually the only adjustment that can bemade to the frequency of operation. No adjustment can be made to any other band.I am pleased to report that low SWR can be found on every band without anyadjustment when the antenna is assembled as per the instructions. However, thecounterpoise must be fixed after the antenna is mounted in position otherwise it iscertainly in the way.The assembled antenna is quite heavy and it is recommended that two men areneeded to do this considering that the base must be insulated from the ground post.Lacking an extra man I called in my big strong xyl who did the job in no time! Aftermounting, the coax cable (prefixed at the centre by the manufacturer thank good-ness) is pulled through the side of the bottom tube and connected eventually to thetransceiver.Before use, it is good practice to check the SWR on each band and I noticed that theinstructions mention a fact that I think escapes many amateurs when taking suchmeasurements. That is that the power must be kept low so that usually an in-builtSWR meter will not show and an external one should be used. This is because mostJap transceivers have harmonics and other unwanted signals when powered upwhich tend to disappear on low power. To conform to FCC and other regs, they areat least 33 dB down but this is still about S3 on an S9 signal.GAP says that the use of an antenna tuner is not required. Tuners will not improvethe performance of the antenna, however they permit a solid state transmitter to putout increased power. Operation of an antenna tuner when the SWR is 2:1 or less ispermitted. High power operation outside the specified bands using a tuner candamage the antenna. This was all music to my ears and is borne out by my ownobservations.My measurements showed a bandwidth on 80 metres of 100 kHz at less than 2:1On all other bands the highest SWR anywhere was 1.7:1 except on 14MHz whereit was 2:1 at the bottom end. It can operate efficiently on 8 bands at 1500 Watts soit is loafing along at our maximum power.In use I have found it as good as the SteppIR (at about 2/3 the price) and thesacrifice of no longer having full HF coverage as opposed to the amateur bands isof no consequence to me. It is not as inconspicuous as the SteppIR but my longsuffering xyl does not seem to mind and the neighbours think its a sculpture! Thephotograph I hope gives some idea of its effect on the landscape.In short, I’m glad I got it!

George G3OGQ

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Bat Detector Review

Inspired by Jim Leviston’s recent purchase of a bat detector I decided to check outthe internet for available products. Jim’s detector was a heterodyne based design,

from Magenta Electronics. Until recently these were very expensive, his purchasewas reasonably priced and the unit he showed us was very neatly made. It hassockets for a headphone and a socket for taking recordings from the unit. The LEDindicator light is placed to illuminate the control knob so that the user can see whatfrequency the device is tuned to. Bat spotting being a nocturnal occupation, Magen-ta has added a bright LED for use as a torch. I was very interested.

A brief internet search for Magenta and Bat Detectors pointed me to their website.The site is very clear and I was soon searching for a prospective purchase. I thenspotted the kit version available for home construction. This brought the price downfurther, and the instructions I down loaded described a construction process I wassure I could manage. I had soon entered my credit card number and details to ordera kit and waited for delivery.The Magenta MKII kit arrived with every part required including a pre drilled case,knobs and even a foil to apply to the enclosure, to give the product a factory finishlook. I methodically sorted and checked the components, surprising myself with myknowledge of the resistor colour code, but also checking with a meter and labellingthem to help later. At this point I should have started taking pictures for a prospec-tive QSX article but my enthusiasm put this from my mind until nearly completed!

The circuit board was easy to populate and I followed the instructions closelystarting with the resistors, working through IC sockets, capacitors, transistors andthen wiring up the transducer on its own little board. I should have fixed thetransducer board to the case before attaching its coax lead to the main board, butwas too keen to get it working before closing the case! The only hairy moment wasattaching the speaker to the case with glue. This has to be done right first time and

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without contaminating the cone itself. Unlike Jim’s version, the kit has provisionfor a headphone socket (supplied) but the case is not drilled for this. I decided toleave this option until I had tested the unit.Once the board was completed I tried to follow the testing procedure given in theinstructions. This involves powering up the device without the ICs in place and

monitoring the current consumption. This failed miserably and theLED would not even light up! I thought there must

be a big error. Taking the meter out I tested thecircuit again and got a lit LED and no smoke!Switching on with the amplifier IC insertedbrought the speaker to life, and still no smoke. Themixer IC increased the background noise at thespeaker. Adding the oscillator IC completes thecircuit so that ultra sonic sound produces audiblesound at the speaker, cue a lot of key shaking andhand rubbing! It worked first time and with all thesmoke contained!The front panel cover is self adhesive. I carefullyremoved the cut outs for the controls and thenapplied the foil to the case. This went very welland gives a pleasing finish. Mounting the board inthe case requires patience as spacers have to bebalanced on screws and offered up while takingcare not to over tighten them and break the mount-ing posts. All this while the speaker and micro-phone wires are getting in the way! The controlknob spindles needed to be cut to length and once

the knobs were fitted the job was a good one.I decided that the socket for headphones should switch the speaker off, the designhad a socket in parallel with the speaker. I carefully wired up the socket and drilleda hole, only to find the case too thick to allow the retaining nut to fit. This wassolved by gluing the socket to the case and has the benefit that it is nearly flush,better than having the nut visible.In use the unit has an LED to show it is on, but this does not light the control knobup. I have heard bats on a couple of occasions but their visits have been short! Thereis always a background of white noise but as soon as a bat is within range thetranslated sound is clearly audible above the background as a series of pulses andtones. I really need to get on to a bat walk with an expert now to start to understandhow to use the device and research the internet for methods and tips! I enjoyedbuilding the unit and I’m sure I will get a lot out of using it!

Chris G7GZB

Club Barbeque 12th July

We were lucky to enjoy better weather than the forecast for our annual BBQand Paul G1DVA assisted by Karina M6KDM produced an attractive

selection of well cooked offerings. There was a very good attendance by membersand families as can be seen in the selection of photographs.

Ron G0WJX

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Medium Wave Loop Revival

With the closure of the BBC World Service earlier this year my attention wasdrawn back to the MW broadcast band. I'm a regular listener of the strong

local 'golden oldies' stations but I was drawn to some of the fringe stations playinga similar genre.

Taking a look at frequency listings I noted plenty of low power am stations, LPAMas they're titled, plus a host of Community and Christian stations. All ideal forenhancement using a loop and listening too on a small domestic radio.

So the aim was to receive frequencies to the top half ofthe MW band, 1200 - 1600KHz on a decent sized loopof more than a metre square. After receiving a heavyduty 4 x 200pf variable capacitor, thanks to AlbertG3ZHE, I built a frame, 2M tall by 1.5M wide, solidenough to match the variable capacitor build !Then I ran 5 turns of 16/0.2 wire around the frame atapproximately 10mm spacing.The result was a loop that tuned between 1116 to wellover 1602KHz and with a cheap portable with it's inter-nal ferrite rod it was time to test reception.First I tried Radio Hope, 1 watt LPAM from HopeUniversity on 1350. It's a poor daytime signal here inGreat Sankey, speech is difficult to follow on the stand-ard radio, SIO122 at best. Bringing the loop to resonanceat this frequency and it becomes a reasonable station,SIO434. I've marked it as a 3 on interference, because

the loop brings up the background band noise plus any household electrical inter-ference is amplified too. I've not heard Knutsford AM on 1350 which can be heardin South Warrington / Lymm, or Range Radio 1350 from Whalley Range Manches-ter but there's time to DX.The next test frequency was 1530, Pulse 2 plays oldies from it's Huddersfield 700watt transmitter, usually a weak signal. Swinging the loop to the east, tune tomaximum gain, and the signal strength then rose to 'local' strength. As the daylightfaded I swung the loop to North / South staying on 1530 and there was VaticanRadio, one of their main MW frequencies. It's not easy to judge loop results fromskywaves due to the unpredictable propagation and cyclic fading associated withthe MW but I was happy with the result.Finally I moved to 1566, two stations of less than 1kw on the frequency are, CountySound Radio, Surrey and BBC Somerset & Bristol. County Sound was an immedi-

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ate catch, a usable signal rather than a DX log. The null on the BBC signal was goodand made all the difference.So what's the future for the loop?For the summer and autumn I will continue enhancing the ground waves of theweak stations. I noted that the Medium Wave Circle group have received permis-sion for 2.5 kw on MW 1512 kHz from Kvarnberget (Stockholm) so when thistransmitter is back on it will certainly be checked out.Then there's the winter MW DX season to look forward to and those transatlanticstations to listen for !

Dave Hackwell G7RKK(Dave sometimes joins the WARC VHF net sessions also known as the CoronationStreet Escape Committee))

Practical Wireless Low Power Con-test 2011

The forecast admittedly wasn’tgood but promised no rain early

on and we intended to erect the an-tenna and gazebos before it started.The forecasters promise was brokenand we started the day wet and gotwetter by the hour. I’ve been wet andcold before but I can’t ever remem-ber being so wet and cold for so long.How the operators managed to keepgoing with others of us holding thecanvas down in the high wind I don’tknow so all credit to them.

Here is a report of the day’s actionfrom Dave G7SKR:-

I've just done a log analysis summary and it is as follows:We worked 136 with one dupe. There were a couple of unknown locator squareswhich we had to deduce post-contest from their Post Code. A total of 22 multipliers(squares) were worked.

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Post-contest log checking seemedto indicate a higher number ofQSOs that needed fixing com-pared to the previous year. We arestill suffering from inaccurate log-ging and typos which really hurtsour score. Maybe this year'sweather had its part to play in thelower overall QSO count com-pared to last year.Country breakdown was: 11GW 6 GM 3 GD 1 GI1 F 2 ONThe rest were GNon-UK stations were TM7T,ON8DM and best overall DX was

ON4POO in JO20dp (approx 14 miles South of Brussels)Best UK DX was GM4JOJ in IO97an (near Peterhead, approx 30 miles North ofAberdeen)

Dave G7SKR

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40m Mini Dipole

The attached photo is of a dipole I constructed recently for 40m using two 40mmobile whip antennas .

Prior to installation each whip was adjusted to 7.03 MHz on a magmount bystanding it on a small metal tea tray and looking for minimum SWR using my MFJantenna analyser.The two whips were then joined together back-to-back, Buddipole style using aT-coupler. The assembly was laid across a plastic chair in my garage, and checkedagain for resonance which was found to be 7.035Mhz.

Still in the garage, Iconnected my FT817rig using a short lengthof coax - not expectingto hear very much withsuch a small, low, in-door antenna. Indeedthere was not much, butI did hear GB2AIR onCW calling CQ. On theprinciple that it is al-ways worth a try, Icalled him with tonguein cheek and he camestraight back to me, giv-ing me an RST559 re-port. Not a bad start for5 watts, into Doncasterusing a small indoor an-tenna only a couple offeet off the ground.

I wondered if it would work as a doublet on any higher bands by feeding it withopen wire feeder. Using an ATU I was able to achieve a low SWR on all bands upto 10 metres but I could receive no signals or even noise.The next step was to erect the antenna outside so I dug out my trusty fibreglassfishing pole that I use for portable working, removed the top two sections which aretoo flimsy to support anything but a wire antenna, and mounted the new antenna toit using two plastic tiewraps. The whole combination was then fixed to my gardenshed using more tiewraps and the antenna hoisted to a height of about 15 feet.

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A quick tune around 40m indicated that the antenna was working and first indica-tions comparing it with my Hustler vertical were that it was giving comparableresults, taking into account the differences between the vertical and horizontalpolarisations. Indeed, in some cases the dipole was better as the vertical was muchnoisier. After listening around for a while I called DK0DW/P (German Navy ClubStation) who I was receiving at RST569. He came back to me with RST339. I alsoworked an SM station who gave me RST 559. It pleased me that I could work intoEurope with such a small antenna and QRP.My next test that day was to have been to replace the coax with open wire feeder totry again with the doublet configuration but the skies darkened and I could hearlightening crashes in the RX so activities were postponed to another day.The following day was fine to start with so I experimented with the open wirefeeder and proved to my (dis)satisfaction that the antenna would not work on anyother band. It started to rain after the completion of the tests so I went indoors andhad a listen on 40m using the openwire feeder. Skip was short - mostly G stationswith QSB and a few weak PAs popping up from time to time from. However, I wasable to determine that my new antenna was far superior to the vertical for short skip.This was not surprising as the dipole was at a low height and hence quite good forNVIR.The whips I used are spirally wound antennas about 4ft long with an adjustablestainless steel whip, of similar length, for tuning. About one third of the way alongthe wound portion the coils are tightly wound to form a loading coil. It is my beliefthat this coil is acting as a choke on frequencies higher than the design frequencyand for this reason the dipole, which is approximately 16 ft long, is not able to workas a doublet over its whole length at the higher frequencies - the outer portionsbeing choked off. This leaves only a dipole with effective length of about 4 ft eachside at its feedpoint with heavy end capacitance loading. Whilst my autotuner willtune this length in conjunction with the openwire feeder, the effective capture areaof the antenna at the higher frequencies must be very small as received signals wereseveral S-points down on what was to be expected. Between making measurementsand dodging rain showers I forgot to record the resonant frequency of the centresection but this can be measured next time I give the antenna an outing.My conclusion is that I have a very useful portable 40m antenna which can bedeployed quickly in limited space. The fact that it will not work on other bands doesnot matter as I have other portable antennas for these bands, including a 40m wiredoublet which I have used successfully over the whole HF range with an ATU.

Jim G3NFB

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Museums on the AirMuseums on the Air on 18th and 19th June provided the opportunity to use ourGB0BAB callsign to promote Burtonwood Air Base on behalf of Gulliver’s WorldTheme Park.Gulliver’s World has taken over the museum and some money and expertise havebeen invested in it with quite dramatic results. The whole exhibition area has beensmartened up and the area is supervised. Entry is via the Theme Park for most ofthe day and provides a steady stream of visitors. The authorities are also apprecia-tive of the publicity we provide and for our part we felt better able to sing thepraises of the exhibits. The car park area near the museum building provides anideal location for a large HF antenna and M0TUB Dave’s ex military pump up mastwas a joy to use. It supported a beam and the VHF antenna.With such a high location for the VHF antennasystem the results were not as good as weexpected but maybe conditions were against us.

On HF the beam and dipole were effective and resulted in 160 contacts over the twodays of operation. There were 60 contacts on the 18th, 29 on 40 metres and 31 on20 metres. On 19th after 1 QSO on 80 metres the remaining 99 were on 7MHz.

Ron G0WJX