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BARSCOMDUNMOW

STEBBING

NOTLEY

RAYNE HALSTEAD

WITHAM

COLCHESTER

COGGESHALL

Monthly Communication of theBraintree and District Amateur Radio Society

GX3XG

G3XG G6BRH

BRAINTREE

G3MMA’sLoopyAntenna

Meeting ournew RegionalManager

December2016

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November 2016

UPDATE !

Chairman’s ChatJohn, M5AJB

Geoff, G1WRH

Well where did all those surplusitems come from at the club sale?I think it goes to show we all keeptoo many items “ that will comein handy one day”

Well they did for the club, we willbe hiring a table at the CanveyRally again next year.

Our Christmas social is on the 5th

December, so come along andenjoy a good evening.

I would like to take the opportunityto thank all members who havehelped out at club events andspecial events this year, anothersuccessful year.

Lastly I wish all members andfamily’s a very Happy Christmas,and a prosperous New Year.

That’s all for this month

Best 73’s John M5AJB.

Meeting ReportsGeoff, G1WRH

The first meeting in November sawthe annual Surplus equipment sale.Items generously donated forauction were wide ranging andnotably included;

● Vintage Cossor and Marconibroadcast radiosAn Eddystone amateur receiver

● Avometers and other testequipment

● Goody bags of components andmultiple other small items

● Garden and DIY tools.

Cont.d on p4

Contents Chairman’s Chat …………… 2 Meeting Reports ..…..………. 2 Derek Loops The Loop .….. 6 Rallies ……………………… 9 Club Meetings and Nets ….… 10 Contests …………………….. 10 Committee Info ……..…… .... 10 Club Info …………………… 11

. . . . . 6

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November 2016Melvin was the auctioneer, Nevillewas the accountant, Edwin was therunner, and Dave was the porter,here seen displaying a doubleencased serial klystron (tripleinsulated, dual yoke), better knownas a DESK TIDY.

Items not having reached areasonable reserve will be taken tothe Canvey Rally, where a table hasalready been booked, (in the smallroom at the back which is better soit is said), and Howard hasvolunteered to sell a few items oneBay where it is anticipated that abetter price might be realised. At thesecond meeting of the monthNeville announced that £139 hadbeen raised to date with monies stillcoming in.

On the second meeting of the monthwe were visited by our RSGB AreaRegional Manager (ARM) KeithHaynes, and his deputy Peter Onion.

Keith gave us twoinformative talks andtook time in betweenand afterwards toanswer questions andgather feedback for theRSGB board via theRegional Council.

The first illustrated talk was apresentation of RADCOM editorand RSGB archivist ElaineRichards’ library of historical facts,documents, pictures and anecdotes.We were informed that the RSGBwas created on 5th July 1913 whenthe London Wireless Club becamethe RSGB. Keith was passionateabout the comradeship (and in mostcases), gentlemanly conductbetween amateurs. One example hegave was during WW2 when theARRL sent food parcels to the UK

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November 2016through the RSGB. When theMinistry of Food passed anedict that the parcels were toobig and contained too muchsugar, the ARRL modified theweight and content of theparcels to get around the issue.

An anecdote was related wherean applicant to the RSGB wassure he could transmit dreamsand smells by radio – afterconsideration he was notrecommended for membership!Keith, licensed since 1967, colouredhis talk with his personal reflectionson field days, and his membershipof Havering and Harlow clubs, andspoke about having to take theMorse test as a matter ofrequirement at a Postmaster Generalapproved testing centre.

He then touched on the formationof the IARU in 1925, theintroduction of the RSGB Code ofPractice, and the evolution of RSGBbadges across the years and hispersonal favourite. Elaine is alwayson the lookout for anything radio orRSGB related of historical interestfor her the RSGB library.

During the tea break Keith chattedinformally to club members, whilstother others discussed his precedingtalk.

Keith then gave his second talk onthe RSGB as it stands and functionstoday. He gave details of the RSGBstructure, and told us about theduties of the ARM, and how allamateurs but members in particularare supported and kept informed ofnew developments in the RSGB. Inthe other direction he advised ushow member feedback is passedfrom him back to the board by aprogramme of monthly contacts.

Keith then listed the twenty or sofunctions carried out by thesurprisingly few 15 permanent staffat HQ. As well as these staff, thereare 1000 volunteers, serving the21,000 RSGB members out of the60,000 licensed amateurs in the UK.

In conclusion the topics of Radcom,Radcom Plus, Radcom Basics, andthe National Radio Centre were alsocovered.

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November 2016

Our annual constructioncompetition produces many newideas and assembly methods whichcall for high professional standardsof construction. One original entryby Derek G3MMA, which he calledthe ‘LOOPY’ was for a folded loopconstructed without the use of anymechanical fixing, and cut foroperation on 20 metres.

Derek’s design was an adaption ofa loop aerial designed by BrianCake KF2YN in Augustine, Florida,USA. The modifications made byDerek combined a matching choke-balun and enabled the loop to beeasily transported and erected inminutes on a sectional mast of 15feet, or suspended from a suitabletree branch.

During his presentation, Derek laidgreat emphasis on the virtues of theloop expounding its ease ofconstruction and deployment atonly 15 feet high, 24 inches fromthe ground and its ability to producereally outstanding results for itssize. Because of the intensive build-up that he gave, he felt duty-boundto ‘put-his-money-where-his-

mouth- was’ and it became logicalto erect the loop at the ‘BankHoliday’ field-week-end-camp’held at the QTH of John ButtonM5AJB

Derek went prepared with tools andall the necessary artefacts to erectthe aerial, but several willing handssimply took the aerial from him..Within minutes, and without anytools John M5AJB, Eddie GØLPO,and Jim GØDCR had put up an 18foot sectional fibre-glass mast, andhoisted the loop aerial weighing 8lbs to its operating height of 15 feetwith the bottom leg just 24 inchesfrom the ground, necessary toobtain the 50 ohm matchingimpedance of the co-axial feeder.

Dave GØDEC then produced aprofessional antenna analyser, andto Derek’s amazement confirmedthat ‘LOOPY’ was on ‘centre’frequency for 20 metres. A quickcheck at the Icom 746 also showedthat the TX/RX had ‘tuned the loopshowing a SWL of 1.5:1.

Operational Notes

The Input Impedance of the loopcan be changed together withachieving the low 1.5:1: SWR bythe simple adjustment of two 10-cmstubs. The aerial cannot be

Derek Loops The LoopDerek, G3MMA

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November 2016connected directly to a co-axial linebecause it will change the frequencycharacteristics. In addition itexhibits a very high common-modepotential at the feed-point of severalhundred volts. It can be fed with acurrent balun or a choke balun. Achoke balun is preferred because theferrite cores of current baluns aresubject to heating and distortion athigh voltages and can result in aserious power-loss. Conversely, achoke-balun does not suffer fromthe same disadvantages.Construction of the loop should bemade using the thickest wirepossible to achieve low loss. It isimportant to arrange the bottom‘leg’ of the loop to be at a nominal24 inches from the ground toachieve a perfect 50 Ohm match.Working to professional standardsthe loop-aerial can be constructedin less than 2 hours

The Loop In Practice

Derek’s comments about the actualperformance of the loop are partscientific, part user-observation andRST reports made through contactswith amateur-stations.

He says that the loop emits a lowangle lobe, and performs well inworking stations that are 2000 miledistance. When the bands are open

it compares very favourably withlong-wires, the G5RV, resonantdipoles, verticals and conventionalloops which often encompassgreater areas and heights, to saynothing about their cost andcomplexity.

When KF2YN Brian Cake theoriginal designer loaded hisexperimental ‘C-Pole’ for the firsttime – using an FT817 with an inputof 100 watts from his QTH inFlorida America,, he contactedES1AX Israel, DB4 Cape Verdi,9Y4ZC Trinidad, F6JXR Crete,DF1UX Germany, 7X3VRKAlgeria, 4XOT Israel, and 9H3YMMalta.

When Derek constructed his firstversion in Thailand as HSØZJH, hecontacted many stations in Europe(5,000 miles) Russia, Asia,Australia, India, and Africa.

When he first loaded the loop at ourAugust Bank Holiday Camp, on the29th of August the first contact wasZ37ØRSM in Macedonia,SV8PDØAR1 in Lescos Greece,LZ2JA Bulgaria, and ZA/IZ7GXBin Albania. Indeed, Edwin GØLPOinformed me that in the receivemode using the Icom 746 the‘LOOPY’ showed an increase of 4points on the ‘S’ meter compared to

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November 2016both the ‘Wyndham’ and the‘Trapped Dipole’ that was 10metres aloft. After 60 years ofAmateur Radio in 1956 I wish I hadthis design from the start, believeme, if you have limited funds,and/or limited space - this‘LOOPY’ is the answer to all yourprayers.

The Concept And Salient Pointsof ‘LOOPY’

● Basic Construction Ability OfThe User

● Easily Obtained Materials

● Simple and Very Low Cost

● Small Vertical Folded-Dipole

● Lightweight – Easily Carriedand Portable

● Maximun Height 15 feet –Suitable For Portable

● 50 Ohm Feed-point NoCounterpoise Needed

● Excellent Performance –Comparable To The G5RV

● Low Angle Radiation At HalfThe Height Of Other Aerials

● Tuning And SWR SettingsEasily Achieved by 10 cmmatching stubs

● Vertical Polarity – FrequencyCan Be Scaled Up or Down

● Independent of Ground – Willoperate very well as a ‘sloper.’

● No Metal Fixings Required

● Easy to Erect With Light-Weight Supports And ‘Guys’

LOOP’S POEM

And still I gazed and still my wonder grewThat this small loop, up at only fifteen feetCould send our lobe far-far into the blue,And so easy to make and it looks so neat

It matched all others, so high, and bought so dearSo small, and rigged so near the ground

But still encompassed the world our words to hear

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November 2016

3 DECEMBERSOUTH LANCS WINTER RALLYDetails from Jason, GØIZR on01942 735 828. [www.slarc.co.uk/rally].

4 DECEMBERBISHOP AUCKLAND RACRALLYMore details from John, G4LRG on01388 606 396 or Brian, G7OCK01388 762 678.

201715 JANUARY 2017

RED ROSE WINTER RALLY,Further details from John, on 07870161953.http://wmrc.org.uk/lowton_winter.htm.

5 FEBRUARY 201732nd CANVEY RADIO ANDELECTRONICS RALLYThe Paddocks Community Centre,Long Road, Canvey Island, SS8 0JA.

Doors open at 8.30am for traders and10.30am for the public. There is freeparking and the venue has disabledfacilities including space outsidemain doors for disabled visitors.There will be trade stands, specialinterest groups and an RSGBbookstall. Refreshments, includingMark’s famous bacon baguettes onsite. Details from Vic Rogers,G6BHE, 0795 746 1694 or DaveSpeechley, G4UVJ, 01268 697 978,g4uvj@btinternet.com.

19 FEBRUARY 2017RADIOACTIVE FAIR ATNANTWICHDetails by email fromstuart@multimediacontrols.com.

26 FEBRUARY 2017CENTRAL COAST AMATEURRADIO CLUB RALLYWyong Racecourse, AustraliaMore information atwww.ccarc.org.au

Rallies

Club Equipment

You can borrow the club’s Aerial Analyser for only £1/day and the MorseTutor (Less Battery) for 50p/2-week session.Ask one of the Committee for information

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CommitteeChairman: John, M5AJB 01787 460947 1 Ross Cottage, Southey Green

Secretary/Membership Secretary: Edwin, GØLPO 01376 324031 42 Panfield Lane, Braintree,

Treasurer: Neville, G8CDG

Ordinary Members: Geoff, G1WRH 01376 323223 07745 569564 Melvin, GØEMK

Club Net - 08.00 pm local time2 Meters (S15) (145.375 MHz)

Club Meetings, Activities and Nets

Dec5 Christmas social.12 Club 2m Net19 Natter evening.26 Club 2m Net

Talks by members on almostany subject are welcome.Please contact the Secretaryto arrange a date.

VHF

Dec4 1000-1600 144MHz AFS AFS Super League26-29 1400-1600 50/70/ 144/ 432MHz Christmas Cumulatives Contest

Contests

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Braintree and District Amateur Radio SocietyThe club meets every 1st and 3rd

Monday of the month at BraintreeHockey Club, Church Street,Bocking. Doors open at 7.30 pm,meetings run from 8 pm to 10 pm.

Membership is £16 annually;Senior members (State Retirementage) and Junior members, under18, pay £10. A door fee of £1 isalso payable at each meeting bymembers and visitors.

BARSCOM is sent to members bye-mail on the first of the month;paper copies are available at thefirst meeting of the month (pluspostage if appropriate).

Members may sell or exchangeequipment etc. before the start ofeach meeting, during the tea/coffeebreak and may advertise inBARSCOM free of charge.

Some members have had problemswith UHF and BZ access, and as aresult the Club Net will nowoperate on 2  metres only. Thisshould make it easier for allmembers to remember thefrequency, and for non-membersto find the net. The net will useV30 (S15) 145.375 MHz, starting20.00 hrs local time on the 2nd, 4th,and 5th Mondays of each month.

Please send articles for publication to i.wager@kaladel.net.

The deadline for submissions for the next edition is 25th of the month. Items will be published in the first

available edition subject to space availability.

For more information and pictures of events and projects seeour Web Site at www.badars.co.uk

Please contact our Chairman for details about commercialadverts.

BARSCOM Editor (Ian, G8MKN) © BADARS 2016 - E.& O.E.

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