3 news - world radio history

2 D-I-Y RADIO September-October 1996

3 NEWS

5 CONSTRUCTIONBUILDING BLOCKSUsing the building block ap-proach can simplify the con-struction of more complexpieces of radio equipment.

7 HAMCLUB NEWSKey items of RSGB Newsfor HamClub members.

8 CONSTRUCTIONA NOVICE ASTUWhen used with a receiveran Antenna System TuningUnit can dramatically im-prove the signal-to-noiseratio. By K Ruiz, G4SGF/ZB2MD.

10 CONTEST FEATURECONTESTS FORNOVICESOnly very few Novices takepart in contests. However,several RSGB contests areespecially suitable for Nov-ices, and help to improveoperating skills. Plus the fullrules of the Poole RadioSociety National NoviceContest.

12 POSTERAMATEUR RADIOBROADCASTSThe RSGB has two broad-casts for all listeners andradio amateurs. Our pull-outposter tells you more aboutthe GB2RS and GB2CWbroadcasts.

Managing Editor: Mike Dennison; Production Editor: Jennifer Preston; News Ed: Steve Lowe; Tech Ed: Peter Dodd; Illustrator: Bob Ryan; Prod Asst: Wai-Yee Man; Secretary: Samantha RalphD-i-Y RADIO is published six times a year by the Radio Society of Great Britain, Lambda House, Cranborne Road, Potters Bar, Herts. Filmset by JJ Typographics Ltd. Printed by Southernprint(Web Offset) Ltd. © Radio Society of Great Britain, 1996. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means,electronic, mechanical, photocopying, recording or otherwise, without the prior written permission of the RSGB. All reasonable precautions are taken by the Radio Society to ensure that the adviceand data given to our readers are reliable. We cannot however, guarantee it and we cannot accept legal responsibility for it. Prices quoted are those current as we go to press. ISSN No: 0959-843X.

14 ON THE AIR2’S COMPANY, THELOG BOOK, BANDBY BANDOur regular columns for theNovice licensee and shortwave listeners. Plus every-thing you need to knowabout the popular 2 metre(144 - 146MHz) band.

16 THE WHATS, WHYSAND WHEREFORESUSING TESTEQUIPMENTUnderstanding how testequipment works is impor-tant when making electronicmeasurements. Here wedescribe how volts, ampsand ohms can be measured.

18 CONSTRUCTIONAN ABSORPTIONWAVEMETERThis absorption wavemeter,by Ed Chicken, G3BIK, isused for checking transmit-ters and oscillators. It canalso be used as a relativefield-strength indicator.

COVER PICTURE:A suspect resistor is checked using amultimeter. The use of test equipmentis described on page 16.

commentAMATEUR RADIO usuallyinvolves direct person-to-person communication. Butthere are cases when infor-mation can be broadcast toradio amateurs in generalor, indeed, those outside ourhobby.

This month’s poster onpages 12 and 13 shows twoways in which the RSGBruns broadcast networks tohelp all amateurs and listen-ers. Firstly, there is theGB2RS News Service whichgives up to date news aboutour hobby each week - in-cluding details of local clubmeetings. Secondly, theGB2CW Morse PracticeService which is provided togive useful on-the-air codepractice for those studingfor their 5 or 12 words-per-minute tests.

The main part of theGB2RS News script is alsoavailable over the telephoneon 0336 407394 (calls cost39p per minute cheap rate,49p per minute at othertimes). The entire script isnow published on theRSGB’s World Wide Webpages (see opposite) sev-eral days before it is avail-able off-air, so if you wantreally up-to-date amateurradio news, check us out.

Mike Dennison, G3XDV

Editor

21 REVIEWTHE AMATEURRADIO OPERATINGMANUALOne of the RSGB’s mostpopular publications, theAmateur Radio OperatingManual provides essentialadvice on how to be a goodoperator on HF, VHF / UHFor microwaves.

22 DIARYDetails of rallies and con-tests taking place duringSeptember and October.

23 PUZZLE PAGEYou could win a copy of theAmateur Radio OperatingManual, worth over £12, inthis edition’s competition.

At the Royal Tournament, ATC Cadet Oliver Waits (right) chats to a BritishMidland pilot at 35,000ft on HF SSB. He is supervised by Pilot Officer Mike Mulroy(left). See news story on page 3.

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3D-I-Y RADIO September-October 1996

NewsRSGB

Laurence of Uganda

Laurence Howell, GM4DMA, operating as 5X1LH from Kampala, Uganda.

L A U R E N C EH O W E L L ,GM4DMA, flewto Uganda in

June, just three days afterRSGB HQ received anurgent request for help fromthe youth developmentcharity Raleigh International.

Raleigh International haveeight remote field sites inUganda, at which a team of130 young venturers workon scientific, community andconservation projects. HFradio links are their onlymeans of keeping in contactwith HQ in the capital,Kampala. But Raleighneeded someone to set upthe communications networkand train the venturers inhow to the use theequipment. The RSGBcontacted Laurencebecause of his knownexperience with expeditionsand, fortunately, he was ableto arrange one month’s paidleave from his job withPhillips Petroleum at the veryshort notice required.

Despite power shortagesand his heavy workload,Laurence also found time tooperate on the amateurbands as 5X1LH during hisAfrican adventure.

Raleigh Internationalneeds morecommunications officers forfuture expeditions toUganda, Belize, Chile,Eastern Malaysia andNamibia. Assignments arenormally for 10 weeks andvolunteers are responsiblefor paying their own air fareand subsistence costs. Forfurther details, contact theStaff Recruitment Office,Raleigh International, 27Parsons Green Lane,London SW6 4HZ, tel: 0171371 8585, fax: 0171 3715116.

RSGB ON THE WEBTHE RSGB LAUNCHED its Internet World Wide WebHome Pages on 1 July. Radio amateurs can browse thelatest GB2RS news script (including the regional newsbulletins) and examine our on-line book catalogue.Information about what’s in the current RadCom and D-i-YRadio also appears, so that non-RSGB members can seewhat they are missing! For non-radio amateur users of theInternet, the pages will provide a way for them to find outmore about our hobby.

New pages will be added regularly, so it will pay to visitthe site frequently. And of course we will be able to publish‘hot’ news stories on the Internet first.

The URL is http://www.rsgb.org

ATC AT ROYALTOURNAMENTSPECIAL EVENT STATIONGB4ATC was on the air fromthe Royal Tournament atEarl’s Court from 9 to 20July. It was operated by fulland Novice licensedvolunteers of the ATC,including Ray Degg, G0JOD;Flt Lt Malcolm Wood,G7VRT; Flt Lt David Horsley,2E1DQQ; Flt Sgt GarethHorsley, 2E1DQK;. JohnMaunder, G0PKU; andDawn Read, G0OIF.

In addition to amateurstations on HF, 2m and 70cmusing equipment loaned byIcom (UK), communicationswere also established on HFand VHF using the ATC’sown specially-allocatedfrequencies. Pilot OfficerMichael Mulroy had madearrangements with pilots ofBritish Midland, Britannia,and Virgin Atlantic airlinersto call the Royal Tournamentstation on an ATC HF SSBfrequency. Air Cadets wereable to exchange greetingsmessages with the pilotsusing a Racal BCC39Btactical HF SSB transceiverloaned by Racal Ltd.

COLLOQUIUM ASUCCESSALMOST 100 delegatesfrom 17 countries attendedthe AMSAT-UK Colloquiumat the University of Surreyin July. The AMSAT-UKPhase 3D Fund received aboost in the form of an RSGBcheque for £11,000. It waspresented to AMSAT-UK’sRon Broadbent MBE,G3AAJ, by RSGBPresident-Elect Ian Kyle,GI8AYZ, and is in additionto the £25,000 donationmade to the fund by theRSGB last year.

BADGER BOARDS,manufacturer of the Piccolotransceiver kit, have movedto new premises. Their newaddress is: 87 BlackberryLane, Four Oaks, SuttonColdfield B74 4JF, tel: 0956374918, fax: 0121 3539326.

THE POOLE RADIOSociety is organising thesecond National NoviceContest. It is on Sunday 22September from 1400 to1600UTC and full details canbe found in our Contestingfor Novices feature on pages10 and 11.


NewsRSGB

BLIND RADIO AMATEURTerry Robinson, G3WUX, isone member of a team offour able-bodied anddisabled adventurerscrossing the Greenlandicecap from east to west.The aim of the expedition isto raise the profile ofexpeditions utilising the skillsof disabled people: Terry isan electronics graduate andthe expedition is making fulluse of his communicationsand DIY skills. A secondteam member, CarlWilkinson, is a qualified skiinstructor and traumaparamedic who lost the sightin one eye during a RoyalArtillery exercise.

Terry is operating as OX/G3WUX during theexpedition using an 5W QRP

TRANS-GREENLAND EXPEDITIONtransceiver and otherequipment loaned by anumber of UK firms. His isthe first amateur radiooperation from that part ofGreenland and he is alsothe first blind person toattempt to cross theGreenland icecap.Trans-Greenland Expedition

ALINCO WINNERIAN WADE, G3NRW, wasthe lucky winner of an AlincoDX-70 HF / VHF transceiverworth nearly £1000 in acompetition in our sistermagazine, RadCom. Thedraw for the prize, donatedby Waters & StantonElectronics, took place at theLongleat Amateur Radio andElectronics Fair on 30 June.

PITCAIRNISLANDSSTAMPSPITCAIRN ISLAND in thePacific, famous as the finalrefuge of the mutineers fromthe Bounty, issues fouramateur radio stamps on 4September.

They are at 20c (listingthe callsigns of this year’smembers of Pitcairn’samateur radio club), two at$1.50 (showing VR6IMrequesting and receivingmedical assistance) and oneat $2.50 (showing AndrewYoung, VR6AY, Pitcairn’sfirst amateur in 1938).Pitcairn has the largestpopulation of amateurs perhead of population ofanywhere in the world:almost one in four.

SCHOOL RADIOCLUB APPEALJOHN ALLSOPP, G4YDM,is organising a radio andelectronics club at his localschool.

Lack of funds means thatthe school is unable topurchase any equipment,so John is appealing for thedonation of old receivers,converters or even simpleVHF / UHF transmitters. AsJohn says: “Anything isacceptable, when you havenothing”. So if you havesomething to offer, pleasecall John on 0191 4162606,or on his mobile: 0378386843.

RSGB ON LINE

http://www.rsgb.org.uk

RSGB ON LINERSGB ON LINE

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Construction FeatureRSGB

Building BlocksTHE THOUGHT ofconstructing aradio receiver isoften regarded as

a rather daunting task. However,there are very good reasons forbuilding your own radioequipment:l It is an ideal form of ‘hands-on’ learning; you learn far morefrom constructing a radio thanjust reading about it.l The cost is far lower thanbuying a commercial receiver.l You can maintain or modifyhome-made equipment;modern commercial equipmentis difficult to repair if it goeswrong.l The sense of achievementwhen you make a radio contact,using a radio that you haveconstructed yourself, is very real- why not try it. The best methodis to use the ‘building block’approach.

All radios require a front panelon which to fix the operationcontrols, such as the volumeand the tuning controls. A radioalso needs a speaker or a pairof headphones and an antennaso you have to giveconsideration to this whenbuilding equipment. It is alwaysa good idea to use a larger boxthan you think that you mightneed so that you have moreroom to add extra circuits if you

want to improve the originaldesign.

All radios require an audioamplifier to increase the level ofthe signals from the previousstages to a level that can beheard on the loudspeaker orheadphones. In this D-i-Y Radiowe will find out how to make theaudio amplifier; the other stageswill be described in later issues.

Building the radio from thelast stage instead of the first hasone outstanding advantage; youcan use the amplifier as a testcircuit for the other circuits.

THE AUDIOAMPLIFIERHERE ARE MANY audioamplifier ICs and modules onthe market which can be usedto simplify the construction. Ifyou completed a Novice Licencecourse, and you built theamplifier described on pages55 to 59 of the Novice LicenceNotebook, then you alreadyhave this stage built and youcan use it without anymodification in your receiverdesign.

THE TBA 820M ICIF YOU HAVE to build an audioamplifier the design using anintegrated circuit, in Fig 1 is

simpler thanbuilding it fromd i s c r e t etransistors. Youcan buy all thecomponents andfix them to aboard, as shownin Fig 2 , and wirethem up asshown in thecircuit. If you feelthat this is a bittoo complicated,a printed circuit

board is available, see the noteat the end of the article.

It is a good idea to use avolume control with a switch, asis used with many radios. ThePC board external wiring isshown in Fig 3.

The audio input is fed to theinput of the TBA820M IC via C5,a 0.1µF coupling capacitor. Theoutput of the IC is fed to thespeaker via another 220µFelectrolytic. These capacitorsallow the audio signal to be inputor output to the IC but block any

Fig 1: Audio amplifier, circuit diagram.

Fig 2: Audio amplifier, component layout.

COMPONENTS LISTResistorsR1 10kR2 1 20RR3 1RR4 56RRV1 50k log potentiometer

with switch

CapacitorsC1, C2 100C3 220C4 47C5, C6 01l1C7 680pC8, C9 11l

SemiconductorsIC1 TBA820IC2 1 2V regulator type 7812

Additional ItemsSpeaker 8ΩPhono socket

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DC component that may upsetthe working of the IC.

All audio ICs have very highgains and wide bandwidths invery small packages. It isreasonable to expect that if careis not taken they will burst intooscillation at odd frequencies.In many cases we do not realisethat this is happening until wefind that they are drawingunusually high currents or aregetting rather hot for no apparentreason.

Some of the resistors andcapacitors in the circuit, shownin Fig 1, are to control the gainand bandwidth and to ensurethat the IC does not becomeunstable and oscillate.

When the amplifier is built ithas many useful functions inaddition to being the last stageof the receiver project. Forexample it can be used fortracing audio signals in amplifier

Fig 3: Twelve volt regulator interconnections.

circuits or for testing that suspectmicrophone insert. It can alsobe used for amplifying a Morsepractice oscillator for groupMorse practice sessions.

A kit of parts for this amplifiercan be obtained, price £8.95 +£1 P&P from JAB Electronic

Components, 1180 AldridgeRoad, Great Barr, BirminghamB44 8PB, tel: 0121 366 6928,fax: 0121 366 6237.

The Students HandbookNovice Amplifier Kit is alsoavailable from JAB ElectronicComponents at £6.95 + £1 P&P.

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HamClub NewsRSGB

Key items of RSGBNews for HamClubMembers THE AMATEUR RADIOInsurance Servicesscheme (available only toRSGB members) isupgraded from 1 Septemberto include breakdown coveron most types of equipmentat no extra charge. For fulldetails on ARIS, write to themat Shepheards Hurst, GreenLane, Outwood, Surrey RH15QS, tel: 01342 844000 orfax: 01342 844554.

A FREE ‘JOTA PACK’will be sent to all groupsapplying for a GB specialevent callsign for JamboreeOn The Air (19 / 20 October).The pack includes lists ofJOTA stations and countriespermitting third-partygreetings messages plus anewsletter from the ScoutsAssociation. Groupsintending to operate duringJOTA using GX, GS etc clubcallsigns should inform EvaTelenius-Lowe at RSGB HQby 4 October if they alsowish to receive a free JOTAPack.

AMATEUR RADIO carboot sales will take placeat RSGB HQ in Potters Barfrom 10.00am to 4.00pm on21 September and 19

October. The RSGB HQbuilding will also be open,with the bookshop, GB3RSshack, National AmateurRadio Museum and Libraryavailable to visitors. Morsetests are available ondemand between 11.00 amand 12.30 pm. For furtherdetails contact MarciaBrimson, 2E1DAY, on 01707659015.

THE RA HAS agreed to arise in the fees for Morsecode tests. From 1September the new rates willbe £15 for the Novice 5WPMtest and £20 for the fulllicence 12WPM Morse codetest.

THE NEW Chairman ofthe RSGB ExecutiveCommittee is HilaryClaytonsmith, G4JKS.

AT ITS MEETING on13 July, the Council of theRSGB elected Ian Kyle,GI8AYZ, as the Society’sPresident for 1997. Heis currently ZonalC o u n c i lMember forN o r t h e r nIreland.

THERE ARE TWOOrdinary Member va-cancies on RSGB Councilfor the term 1996 - 97 causedby the resignation of DavidEvans, G3OUF, and NigelRoberts, G4IJF. Ian Kyle’s,GI8AYZ, election as 1997President has also createda vacancy as Zonal Councilmember for NorthernIreland. Further details fromFay Huxley, 2E1EUA, atRSGB HQ.

THE RSGB WAS atEurope’s largest amateurradio exhibition, HamRadio,in Friedrichshafen, Ger-many, in June. RSGBMarketing Manager MarciaBrimson, 2E1DAY, reportedthat the sale of RSGB bookswas brisk, with the RSGBIOTA Directory and RadioCommunication Handbookbeing the two best sellers.

REPORTS ON THE May1996 Radio AmateursExamination and the June

1996 Novice RadioA m a t e u r s

Examinationhave been

received from City & Guilds.Anyone wishing to receive acopy should send a 1st or2nd class SAE to LynnetteRanger, 2E1EKT, at RSGBHQ, specifying which reportis required.

ADMINISTRATION ofthe RSGB Audio VisualLibrary (AVL), previouslyrun on a volunteer basis,has now been taken over byRSGB headquarters. Thenew contact for enquiriesabout the AVL is JohnDavies, G3KZE, tel: 01707659015.

THE RSGB WILL have abookstall and membershipinformation stand at thefollowing rallies and events:1 Sept Telford Radio Rally,Shropshire; 21 Sept ScottishAmateur Radio Convention,Glasgow; 4 - 6 Oct RSGBInternational HF and IOTAConvention, Old Windsor; 18- 19 Oct Leicester AmateurRadio Show.

THE CHAIRMAN OF theVHF Contests Committee,Steve Thompson, G8GSQ(formerly GW8GSQ), hasrecently changed addressand phone number. He cannow be contacted at PO Box2399, Reading, Berks RG74FB; tel / fax: 0118 982 0848(phone evenings / weekendsonly); or e-mail:[email protected]

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A Novice ASTUBy K Ruiz,G4SGF/ZB2MD

IF YOU ARE Ashort wave listeneror a licensed radioamateur an ASTU

(Antenna System Tuning Unit)is very useful. The purpose ofan ASTU is to adjust the antennafeed impedance so that it is veryclose to the 50Ω impedance ofthe antenna of the receiver ortransmitter, a process knownas matching. When used with areceiver an ASTU candramatically improve the signal-to-noise ratio of the receivedsignal. On transmit it is essential

COMPONENTS LISTCapacitorsC1, C2 350pF

InductorsL2 27µH coilL3 10µH coilL4 2.2,µH coilL5 1µH coilL6 65µH coil

Other items2 SO239 sockets (in and out)1 2P6W switch S1Box - Any small plastic or metal boxcan be used.2 Plastic knobs for capacitors

4 Stick-on feetMounting screws for the capacitorsspecified are M2.5.Screws, nuts and washers requiredare also to mount the input andoutput sockets.

Fig 1: Basic circuit of the ASTU.

Fig 2: Coils added for other bands.

that the antenna is matched tothe transmitter so that the poweramplifier operates efficiently.

The ASTU described here isbased on a design by DougDeMaw, W1FB. The compo-nents used are readily available(see note at the end of the article)and the unit will handletransmitting powers up toaround 5W. It matches over thefrequency range of 1.8 to 30MHzwithout difficulty.

CIRCUITTHE BASIC CIRCUIT is shownin Fig 1 . On transmit, the signalpresented at L1 is coupled intoL2, which forms a resonantcircuit with C1. The RF energyfrom L1/C1 is coupled to theantenna via C2.

Unwanted components of thetransmitter waveform, such asharmonics, are rejectedbecause they are not on theresonant frequency of C1 andL2.

On receive only the signals inthe resonant pass-band of C1/L2 are coupled to the input ofthe receiver via L1.

In this design C1 and L2 areinitially chosen to be resonantin the 80m band. In order tomake the ASTU operate onother bands we need to changethe value of either L2 or C1. It iseasy to change the value of L2by a simple modification usingswitched inductors as shown in

Fig 2 . S1 in position 1 leavesthe circuit as in Fig 1. In positions2, 3 and 4 it brings L3, 4 or 5 intocircuit in turn. The new coils areplaced in parallel with L2changing the inductance of thetuned circuit so that C1 nowtunes other frequencies. Bychoosing appropriate valuescontinuous coverage from 10 to80m is obtained. Inductances inparallel behave as resistors inparallel:

[1/Ltot

= 1/La+ 1/L

b]

In order to tune 160m weneed an extra coil as shown inFig 3 . When S2 is in position 1the circuit is exactly as in Fig 2.

With S2 inposition 2, L6 isplaced in serieswith L2, and thetotal inductanceis the sum of L2and L6. C1 cannow tune 1 60m.The functions ofS1 and S2 can becombined in asingle switch, asin Fig 4 .Fig 3: L6 added for 160m. Fig 4: Two-pole switch for all bands.

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NOTEALL PARTS canbe obtained fromJAB ElectronicC o m p o n e n t s ,1180 AldridgeRoad, Great Barr,Birmingham B448PB. A completekit, included apunched box, isavailable from thesame source at£24.95.

Fig 6: Coils are mounted on the switchassembly.

CONSTRUCTIONL1 IS FORMED BY winding fourturns of 22SWG enamelledcopper wire over L2, as in Fig 5 .One end of L1 is connected tothe end of L2, and where theseare joined is a common earthconnection. The transceiverinput is connected to the otherend of L1.

All components except thecapacitors are assembled onthe switch, see Fig 6 .

Note from the circuit diagramthat the rotor of C1 is earthed,whereas no part of C2 is atearth potential. In order to avoidseverely detuning the ATU whenmaking adjustments to C2, aplastic control knob should beused for C2. If a metal box isused, ensure that no part of theshaft touces the box.

The capacitors are mountedusing M2.5 screws. Take carethat these do not foul the vanesof the capacitors, which is easilydone. An appropriate numberof washers between the box

Internal view of the ASTU. A small plastic or metal box makes a suitable housing.

and the capacitors will preventthis happening.

OPERATIONThe best indication of optimummatching on transmit can beachieved using an SWR bridge;the ASTU is tuned for minimumSWR. If the ASTU is used forreceive only the best antenna-to-receiver match can beachieved by listening for max-imum signal while adjusting theASTU.Fig 5: L1is wound over L2 as shown.

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Contest FeatureRSGB

NOVICES ANDcontests do notusually go togetherin the same

sentence. After all, don’t youneed high power and bigantennas to take part incontests? In fact, the answer is‘no’, you don’t, at least not in allcontests. The organisers ofseveral contests have realisedthere is a need to cater forNovices and have introducedspecial rules for them to putthem on a more equal footing.

The Poole Radio Society haseven organised a contestspecially for Novices. It has beendesigned to give Novices theirfirst taste of contests, with rulesspecifically designed to besimple and easy to comply with,encouraging the greatestpossible participation. ThePoole Radio Society’s NationalNovice Contest takes place onSunday 22 September, and thefull rules are given opposite.

RSGB CONTESTSSEVERAL RSGB contests arealso particularly suitable forNovices, although all RSGBmembers can take part,regardless of their licence class.Here are some RSGB contestsin which Novices may like tohave a dabble:

The Slow Speed CumulativeContests encourage part-icipation by those whose Morseis perhaps a little rusty. This isbecause the maximum speed isset at 12WPM - and never fasterthan the other station is sending- so even if you can only manage5WPM you can still take part.These contests are on now:Monday 2 Sep, Tuesday10 Sep, Wednesday 18 Sep,Thursday 26 Sep and Friday4 Oct, from 1900 to 2030UTC,between 3540 and 3580kHz onCW. Send an RST report plusyour first name. Contacts withNovices count 20 points (andonly 5 points between full licenceholders), so Novices are muchsought-after by all taking part.There is another session of SlowSpeed Cumulative Contests inApril.

The RSGB 21 / 28MHzContests, o n SSB on6 October an d CW o n20 October, each have QRPsections which allow a maximumof 10W output power, soNovices are competing onlyagainst others using low power.In these contests, you shouldsend an RS(T) report and serialnumber, starting at 001, as wellas your county. The idea is tocontact as many differentcountries as possible on each

of the two bands. In the SSBcontest Novices can, of course,only participate on 28MHz.

For Class A Novices, the ‘LF’Cumulative Contests, whichtake place in January, will alsobe of interest. Three short (two-hour) mid-week eveningsessions take place on both 160and 80 metres CW. A ‘speedlimit’ of 12WPM is enforced from1950 - 1960kHz and 3560 -3580kHz, so even those whoare not yet completely proficientin Morse code should have nofears. Entrants receive 3 pointsper QSO, except for QSOs withNovices, which count 20 points,so Novices are again alwaysvery much in demand!

Both Class A and B Noviceswill find the two 50MHzBackpackers Contests in Juneand July great fun. A 3W outputsection means that Novices arecompeting on equal terms withfull licensees. The idea is tooperate from a good VHFlocation by literally ‘back-packing’ your complete stationto the transmitting site. You areallowed to use a car battery, butyou’re not allowed to charge thebattery by running the carengine!

For Class B Novices whooperate only on 70cm, the432MHz FM Contest, also inJune, will be of particularinterest. The single band andmode means that Novices oftenhave all the necessaryequipment already available.You can operate from home ortry to improve your score byoperating portable from a localhigh spot, and in this contestyou are allowed to keep yourcar battery fully charged!

Contests for Novices

PHOTOGRAPH: STUART MCKINNON, G0TBI

Club contest operations provide anexcellent opportunity for Novices to learnfrom more experienced amateurs. This isa typical club contest operation: membersof the Stourbridge and District AmateurRadio Society at their HF SSB Field Daysite in September last year.


Contest FeatureRSGB

THE EXCHANGEOF COURSE, these aren’t theonly contests in which Novicescan take part. Most weekendsthere are international HFcontests on SSB or CW (orsometimes both) on at least oneor two bands. And there aremany more RSGB VHF / UHFcontests in which Novices can‘have a go’.

Always listen first to makesure you know what ‘exchange’(information) is expected of you.Almost all contests require anRS or RST report (59 or 599 isusually sent), plus some otherdata. In some contests this is a‘serial number’ (001 for the firstcontact, then 002, 003 etc), but

FULL RULES FOR THE SECOND POOLE RADIOSOCIETY NATIONAL NOVICE CONTEST

1. Date and Time: The contest takes place on Sunday 22September from 1400UTC (3pm local clock time) to1600UTC (5pm local clock time). NB: times one hour laterthis year!

2. Bands / Power: Contestants can use the 50MHz (6m)and 430MHz (70cm) bands, using only those sections ofthe bands, modes and powers permitted by the Novicelicence, and in accordance with published band plans.Stations working Novices using CW are particularly askedto ensure that they send no faster than the Novice station.

3. Sections: There will be a single section for all Novices.The station should be operated by the Novice licence-holder throughout the contest in accordance with theNovice licence. Help and encouragement in setting upstations and logging etc is welcomed, subject to licenceconditions. The same basic callsign must be usedthroughout the contest (eg 2E1JHG and 2W1JHG/M arethe same station).

4. Locations: Stations may operate from up to twolocations during the contest. Stations entering may switchbetween the two locations as they wish. A location is anyarea of land within a circle of 10 metres diameter.

5. Exchange: Each station may only be contacted forpoints once on each band. Usual reports should beexchanged for the mode being used (eg 57 on phone, 579on CW). In addition some indication of location (such aslocator, county, town, village) must be exchanged. Serialnumbers are not essential for this contest, but pleasemake sure you log the time of each QSO accurately. Atypical exchange might by “2W1GHF this is 2E1JHG, youare 5 and 4 in Poole, Dorset”.

6. Scoring: Scoring is very simple. Novices score 3 pointsper QSO. No points will be available for duplicate contacts,even after a change of location. No points will be availablefor QSOs through repeaters etc. There are no multipliers.

7. Logs: Logs should be sent to Colin Redwood, G6MXL,45A Lulworth Avenue, Poole, Dorset BH15 4DH to arrivein time for adjudication over the first weekend of October.Any recognisable paper log sheet will be accepted, providedit contains for each QSO, the time, band used, callsign ofstation worked, reports exchanged and location of stationworked and points claimed. RSGB HF or VHF log sheetscan be photocopied from a recent RSGB Call Book, andwill make the adjudicators’ job a lot easier. Separate logsheets for each band should be used.

Make sure that you include you own callsign, name andaddress, and details of the location(s) used for the contests.Please add up your score for each band and in total andwrite is somewhere clearly on the log sheet.

Checklogs from all listeners and transmitting stationswill be very welcome.

8. Winners: The winning station on each band and overallwill each receive a small cup to retain. All entrants willreceive an A4 certificate for entering and a summary of theresults, providing a large enough stamped envelope isenclosed with the entry. Certificates and results summarieswill also be available to anyone sending in a checklog onthe same basis. Please indicate the names of each operator,if more than one operator requires a certificate. A specialcertificate will be awarded to the Novice station presentingthe neatest hand-written log.

others require a zone, IARULocator, County, IOTAReference or WAB Square etc.A few minutes spent listeningwill enable you to discover justwhat is required.

Contests are one of the bestways for all operators (not justNovices) to improve theiroperating skills, but - perhapsjust as importantly - they aregreat fun. Contests are alsogood club activities, and onceyou have developed yourcontest operating skills a littleyou will find that your club will becalling on your skills to helpthem in the next club contesteffort. Join in and have somefun!

Paul Dennison, 2E1DBI/P, on Dunstable Downs during the RSGB 432MHz FM Contest inJune. His antenna is a 9-element Yagi, with a cunning mechanical (hinge and string!)arrangement to provide horizontal / vertical polarisation switching.

Amateur Radio BroadcastsAmateur Radio Broadcasts

RSGB, Lambda House, Cranborne Road, Potters Bar, Herts EN6 3JERSGB

GB2RS NEWS BROADCAST SCHEDULE (SUNDAYS)Band & mode Frequency MHz Local time80m SSB 3.640, 3.650 or 3.660 0900, 0930, 1000, 1030, 1100, 1130 or 180040m AM 7.0475 09006m FM 51.530 0930, 1030, 1100, 1130 or 1200.2m FM 145.525 (S21) 0900, 0930, 1000, 1030, 1100, 1200, 1800, 1900 or 2100.70cm FM 433.525 (SU21) 0930, 1000, 1030, 1200, 1900, 1930, 2000 or 2100.

Broadcasting is not permitted by the ordinary Amateur Radio Licence, but the Radio Society of Great Britain has special permission to provide two broadcasts intended for all radio amateursand listeners. The first is a weekly news bulletin, broadcast every Sunday under the callsign GB2RS. It is transmitted from a large number of stations throughout the country and on severalfrequency bands. The GB2RS bulletin consists of national amateur radio news, followed by details of club meetings in the listener’s local area during the coming week.

The other broadcast is the RSGB Morse practice service, GB2CW. It is intended to assist those preparing for the RSGB 5WPM and 12WPM Morse code tests which are necessary for aNovice or Full Class A amateur radio licence. There are GB2CW broadcasts every day of the week. Some cover a wide area, whilst others have more local coverage.

There are nearly 100 transmissions from both GB2RS and GB2CW throughout the country each week - far too many to list in detail here. The full schedules of both GB2RS and GB2CWcan be found in the RSGB Amateur Radio Call Book or are available free of charge from the address below.

GB2CW MORSE PRACTICE SERVICE SCHEDULEBand & mode Frequency MHz Day and local time160m SSB / CW 1.850 Sun 2015160m SSB / CW 1.976 Mon 2030, Thu 193080m SSB / CW 3.550 Wed 1930, Fri 1830, Sat 1930, Sun 193080m SSB / CW 3.600 Sun 1100, Wed 200080m SSB / CW 3.640 Sun 09452m FM 145.250 or 145.275 Most days at 1830, 1900, 1930, 2000, 2030 or 2100.

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On The AirRSGB

THE LOG BOOKJULY WAS OFFICIALLY declaredto be ‘solar minimum’ month bythe Space Environment Centrein Boulder, Colorado. This meansthat, slowly, HF propagationconditions should now begin toimprove as solar activity increases.As this happens, the maximumusable frequency will rise, toreward radio amateurs with longdistance contacts on the HF bandsand, eventually, 6 metres. Even inJuly, 28MHz provided strongsignals from southern Europe,thanks to Sporadic E propagation.

2’s CompanyNews and Reports from Novice Licensees

EVEN NOW, at thesolar minimum, it isstill possible forNovices to contact

many different countries onthe 28MHz band (10m).D Shallcross, 2E0AFI, fromDerbyshire sent in an entry tothe 1996 28MHz CountriesTable which is run in the HFNews column in RadCom. Hehas worked 31 countries on thatband using CW and SSB during1996 alone.

2E0ANY made a number ofcontacts on 28MHz during theRSGB IOTA Contest on 27 / 28July. He also participated in thefirst RSGB ‘RoPoCo’ (RotatingPost Codes) contest for 1996,which took place in April. Thiscontest provides a realchallenge in Morse-copyingability, as it requires theexchange of post codesbetween participants. P AWilliams, 2E0AJE, ofWakefield, West Yorkshire alsoentered this contest, coming in30th place out of 49 entrants.

It is good to see Novicesentering UHF contests too.D-i-Y Radio subscriber MrsMargaret Snary, 2E1AQS , inEnfield, London represented theSouthgate Amateur Radio Clubin the Affiliated Societies sectionof the 432MHz Fixed Stationcontest in February. She usesan impressive 48-elementantenna array on 70cm. S ASugden, 2E1AXO, in Bracknell,Berkshire also entered thiscontest, making 18 contacts with

his 3W and 19-element beamantenna.

There are a number of HFand VHF / UHF contests whichtake place around this time ofyear which are particularlysuitable for Novices. Turn topages 10 and 11 for our featureon Contests for Novices.

FIRST KENYANNOVICEA NOVICE LICENSING schemehas been introduced in Kenya,and the first licence was issuedto Anand Raicha, 5Z4RAN, on13 June. Anand is a student atKisumu Academy and has beena short wave listener for severalyears. He was one of the firstfew to start the preparations forthe exams when a Novicelicensing scheme was proposedin Kenya. Anand is a member ofthe Scout movement and hastaken part actively in JamboreeOn The Air over the last twoyears. His father is Max Raicha,5Z4MR.

For example, there was a goodopening to southern Europe on theSunday morning of the RSGB IOTAContest on 27 / 28 July. Many EA

(Spanish), I (Italian) and CT(Portuguese) stations on islandsand the mainland were worked and,conversely, 9H0A (Malta) contactedhundreds of northern Europeanstations, including many in Britainand Germany.

The Historic Scotland Weekendtook place on 24 / 25 August. Tenspecial event stations, all usingGB2 prefixes, were on the air fromhistoric sites around Scotland. Mostactivity was on 20, 40 and 80 metresSSB, and an award is available forthose who worked or heard a certain

Anand Raicha, 5Z4RAN, at his station in Kisumu, Kenya. Note Anand’sbrand-new log book, open at page 1!

Mal Johnson, VK6LC, has activated numerousislands off the coast of Australia for the RSGBIOTA awards programme. The small photos onhis QSL card show him on some of them.


On The AirRSGB

THE LOG BOOK

The Amateur Radio Spectrum: The 2 metre Band

Band by Band

number of stations. Full details canbe obtained from Mike Dalrymple,GM4SUC, 11 Shawfield Avenue,Ayr, Ayrshire KA7 4RE.

Listeners to the VHF bands canexpect to hear plenty of activityover the weekend of 7 / 8September. The RSGB 144MHzTrophy contest takes place from1400UTC on the Saturday, for aperiod of 24 hours.

Short-wave listeners interestedin increasing their ‘countries heard’score should find the CQ WorldWide SSB contest on 26 / 27

October a productive time. Thiscontest runs for 48 hours from0000UTC on the Saturday and is thebiggest international HF contest ofthe year, with literally thousands of

stations taking part. Manygroups mount major‘DXpeditions’ to rare countriesor islands specifically forthis contest. A number ofAmerican amateurs travel toCaribbean islands for‘CQWW’, as it is known, whilstEuropeans tend to make tracksfor the Canary Islands (EA8),Corsica (TK), Malta (9H) andother Mediterraneancountries, Luxembourg (LX)and the Channel Islands (GUor GJ).

TWO metres, the144MHz band, isthe most heavily-used VHF / UHF

band in most parts of thecountry. Available to both ClassA and B full licensees (but notNovices), the 2 metre bandprovides good, reliable, localcommunications with the addedexcitement of occasional long-distance (‘DX’) openings.

The 2m band is twomegahertz wide, from 144 to146MHz. It is allocated on aprimary basis to the AmateurService and the AmateurSatellite Service, with amaximum power in the UK of26dBW, or 400W.

Communications on 2m isnormally limited to a fewkilometres for low-power FMtransmissions using simpleantennas, up to a few hundredkilometres for higher-poweredstations using high-gainantennas from good locations.Unusual propagation some-times occurs on 2m which can

extend these rangesconsiderably. Tropospheric(‘tropo’) propagation occurstypically when there is a high-pressure weather system closeto the UK, and provides strongsignals from the near Continent.Auroras can provide propa-gation to northern Scotland(from Southern England) andScandinavia or even Russia;whilst Sporadic E gives strongsignals from Italy and CentralEurope.

There is a huge variety ofcommercial amateur radioequipment available for the 2mband. New equipment costsfrom around £100 for a simplehand-held transceiver, whilstAKD (tel: 01438 351710) makesa 2m FM ‘base station’transceiver for under £200.

Antennas used on 2m varyfrom a simple quarter-wavevertical used for omni-directionallocal coverage, up to multi-element Yagis with boom-lengths in excess of 20ft (6m).However, a small rotatable 3 or

5 element Yagi will still provideuseful gain and directivity andcan look like a TV aerial ifmounted on a chimney.

QSL card from Rich Kingston, G4RHM, who isnow working in Kathmandu, Nepal, and is activeas 9N1RHM.

BAND FACTSAllocation: 144.000 - 146.000MHz (Primary)UK Band Plan:144.000 - 144.150MHz ........ CW (Morse) only144.150 - 144.500MHz ........ SSB and CW (Morse)144.500 - 144.845MHz ........ All modes144.845 - 145.000MHz ........ Beacons145.000 - 145.200MHz ........ Repeater inputs145.200 - 145.600MHz ........ FM Simplex channels145.600 - 145.800MHz ........ Repeater outputs145.800 - 146.000MHz ........ SatellitesActivity:144.050MHz ............. CW calling frequency144.300MHz ............. SSB calling frequency144.600MHz ............. RTTY144.625MHz ............. Packet radio144.650MHz ............. Packet radio mailboxes144.675MHz ............. Packet radio145.200MHz ............. Emergency communications145.225MHz ............. Emergency communications145.250MHz ............. GB2CW Morse practice145.500MHz ............. FM calling channel145.525MHz ............. GB2RS news broadcasts145.550MHz ............. Rally ‘talk-in’

16 D-I-Y RADIO September -October 1996

Technical FeatureRSGB

Using Test EquipmentMOST electricalmeasurementsrely on themeasurement of

voltage and current. To this endmany types of instrument havebeen developed such as meters,oscilloscopes, spectrumanalysers etc. This articledescribes the simplest yet mostused of measuring instruments,the multimeter.

CURRENT ANDVOLTAGEMEASUREMENTSTHE MULTIMETER, shown onthe cover, tends to be used formost voltage and currentmeasurements. A multimetercan be either analogue or digital.They are relatively cheap andusually provide resistancemeasurement as well. Becausethese instruments are so cheapit is usually not worth makingone, other than for theexperience.

The following description ofmeasuring voltage and currentis restricted to the method ofmeasurement using ananalogue meter.

The analogue metercomprises a coil in the field of apermanent magnet. The coil, towhich the pointer is fixed, is freeto move on a spindle and isbiased to the left-hand side ofthe scale with a small spiralspring.

Current flowing through thecoil creates a magnetic field inopposition to the permanentmagnet field. The greater thecurrent the more the coil andthe pointer is moved to theright-hand side of the scale.The meter is calibrated inuni ts of current, usual lymicroamps (µA).

MEASURINGCURRENT - THEAMMETERTO MEASURE CURRENT themeter is placed in series withthe circuit. As a result of this,all the current flowing in thecircuit must pass through themeter.

Because the meter can onlymeasure µA, the range mustbe extended if it is to measuremilliamps (mA) or amps (A).This is achieved by connectinga resistor in parallel with themeter to provide a path for theaddit ional current. Thisresistor is called a shuntresistor and is shown in Fig 1 .

If the meter is to coverseveral current ranges then aselection of shunt resistors arerequired. These are usuallyinserted into the meter circuitwith a switch in a multimeter(described later).

MEASURINGVOLTAGE - THEVOLTMETERTHE SAME ANALOGUE µAmeter can be used to measurevoltage. In this case the basicmeter movement is used with aresistor in series, as shown inFig 2 . This resistance is called amultiplier. The current multipliedby the resistance, by Ohms law,gives the voltage drop acrossthe resistance. An instrumentused this way is calibrated interms of the voltage drop acrossthe resistor to read voltage.

The range of a voltmeter canbe extended to measure a widerange of voltages. This isaccomplished by addingadditional resistances in serieswith the meter in a multimeter.

When used to measurevoltage in an electronic circuit athe voltmeter must not affectthe circuit under test. An ideal

Fig 1: To measure current you must break the circuit at some point and connect the meterin series at the break. A shunt resistor expands the scale of the meter to measure highercurrents than it could normally handle.

C RSGB DY320


Technical FeatureRSGB

voltmeter would have an infiniteinput impedance, which wouldprevent the voltmeter fromdrawing current from the circuitunder test.

Real-world voltmeters,however, have a finite value ofinput impedance so be awarethat in certain circumstancesthe voltage you are measuringwill change when themeasurement is made becausethe meter adds some load to thecircuit.

MEASURINGRESISTANCETHE SAME ANALOGUE µAmeter can be used to measureresistance. In this case the basicmeter movement is used with abattery and a resistor in series.The resistor being measured isthen connected in series withthe meter and calibrationresistor using the meter leads.The current flowing throughthe meter is determined by thevalue of the resistor beingtested. Although the meter ismeasuring current the scale is

calibrated in terms ofresistance, as shown in Fig 3.

THE MULTIMETERA MULTIMETER is a piece oftest equipment that mostamateurs should know how touse. The simplest kind ofmultimeter is the volt-ohm-milliameter (VOM). As its namesimplies, a VOM measuresvoltage, resistance and current.VOMs use one basic metermovement for all functions. Themovement requires a fixedamount of current (often 50µA)for a full-scale reading. Asshown earlier, resistors areconnected in series or parallelto provide the voltage or currentmeter reading. In a VOM, aswitch selects various rangesfor voltage, resistance andcurrent measurements. Thisswitch places high-valuemultiplier resistors in series withthe meter movement for voltagemeasurements. It connects low-value shunt resistors in parallelwith the movement for currentmeasurements. These paralleland series resistors extend the

range of the basic metermovement.

Measuring resistance with ameter involves placing the meterleads across the component orcircuit whose resistance youwish to measure. Make sureyou select the correct resistancescale. The full-scale-readingmultipliers vary from 1 to 1000and higher.

When the range you are goingto use has been selected thescale has to be zeroed. This isdone by connecting the testprobe leads together andadjusting the ‘Zero OhmsControl’ for full scale meterdeflection. The leads are thenconnected across the resisterbeing measured as shown inFig 3.

Note that the scale iscompressed on the higher endof the range. For best accuracy,keep the reading in the lower-resistance half of the scale. Onmost meters this is the right-hand side. Thus, if you want tomeasure a resistance of about5000Ω, select the R x 1000scale. Then the meter willindicate 5.

Fig 3: An ohmmeter being used to measure the value of a 300 Ωresistor.

Fig 2: When you use a voltmeter to measure voltage, the meter must be connected inparallel with the voltage you want to measure.

C RSGB DY319

C RSGB DY321



A Simple HF Absorption WavemeterBy E Chicken,MBE, BSc,MSc, CEng,FIEE, G3BIK

THERE IS A needfor an absorptionwavemeter in al i c e n s e d

amateur’s radio station. Its primepurpose is to check that thetransmitter is radiating on theintended waveband, and thatthe transmission is free fromspurious emissions such asharmonics of the carrierfrequency.

It can also be very useful whentuning the frequency multiplierstages of a transmitter or of areceiver’s local oscillator, or forbroadly checking the frequencycoverage of a home-builtoscillator. It can even be usedas a relative field-strengthindicator whilst experimentingwith transmitting antennas.

What it cannot do is preciselymeasure the frequency of atransmitted signal. It will indicatethe presence of a locallygenerated RF radiation, but canonly approximate the frequencyto within a band some kilohertzwide, eg the 3.5MHz or the18MHz amateur band, or theharmonics of such emissions.

THE CIRCUITTHE ABSORPTION wave-meter, in its most basic form,consists of a parallel inductance/capacitance resonant circuitwhich is tuneable, plus someform of indicator to show thepresence of RF energy withinthe wavemeter’s tuned circuit.When located in the presenceof a relatively strongelectromagnetic field such asthat from a transmitting antennaor the PA tank circuit of atransmitter, the resonant circuitof the wavemeter absorbs asmall amount of the radiatedRF energy by electromagneticinduction into its coil.

As there is no built-in method

of RF amplification, the indicatorwithin the wavemeter must relyentirely upon the absorbedenergy to power it.

Possibly the simplest form ofindicator would be the inclusionof a low power torch bulb wiredin series with the resonant LCcircuit as shown in Fig 1 (a) .

Whilst this does work andshould in principle satisfy thelicensing authority, it is ratherinsensitive in practice, andhence would be of limitedusefulness. A more sensitiveindicator is the moving-coilmeter but it requires a DCelectric current.

Bearing in mind, however, thatthe RF energy absorbed by thewavemeter causes anoscillatory voltage to bedeveloped across its tunedcircuit, a simple diode detectorcan be used to convert thatalternating RF voltage into adirect voltage, which in turn canbe used to drive current throughan indicating meter.

The voltage produced in thisway will be very small inmagnitude, hence the need fora sensitive moving-coil meter,ie one with microamps (µA) FSD(full-scale deflection).Fortunately, physically smallmeters, often described as‘volume level’ or ‘battery level’indicators, can be purchased atvery modest cost, and aretypically rated at 100µA FSD.Such meters are ideal for use ina wavemeter which seeks onlyto give an indication rather thanan absolute value of current orvoltage, the meter scale beingignored.

The limited selectivity of asingle tuned circuit is one reasonwhy the RF tuning indication bythe wavemeter is broadband.Further, the electrical loadingeffect of the detector/indicatorcan significantly worsen thatselectivity.

A bulb with its resistivefilament is particularly likely todampen the resonant circuit andhence broaden the tuningindication, as would a diodedetector if connected directly tothe moving-coil meter.

One way to minimise theloading effect of the diode/meteron the tuned circuit would be toconnect the diode detector to atapping point some way downthe coil rather than to the top ofit, ie by not connecting it directly

Fig 1: Evolution of the absorptionwavemeter circuit.

Fig 2: The simple but effective practicalwavemeter.

C RSGB DY328

C RSGB DY329



across the tuned circuit (Fig1(b )). However, that wouldcomplicate the construction ofwhat is otherwise a simple testinstrument.

This minor design problem isovercome by including a low-value resistor in series with themeter, as shown in Fig 1(c) , toincrease the impedance of thedetector circuit. The resultantselectivity and simplification ofconstruction more thancompensates for the slightreduction in sensitivity. Fig 2shows the circuit of the HFwavemeter. The small-valuecapacitor across the meterterminals is theoreticallyintended to maximise the levelof the DC voltage output fromthe diode rectifier/detector, andto some extent protect the meterfrom excess RF. It can beomitted without noticeable effecton sensitivity.

COILSTHESE CAN BE PURCHASEDcommercially or hand-wound as

detailed later. A convenient andlow-cost range of encapsulatedRF inductors, in the microhenry(µH) range and in a preferredseries of fixed values, isavailable (see ‘componentavailability’ at the end of thisarticle). Each consists of a coilwound on a ferrite-based formerin polypropylene encapsulation,11.4mm long by 5mm diameter,with axial lead terminations forease of soldering into circuit.Alternatively, coils may be hand-wound on to short lengths ofreadily available PVC water pipeor conduit, using enamelledcopper wire. Tables 1 and 2give the details. The frequencyrange for coils and capacitor ofknown values can be calculatedquite simply by using theformula:

F (MHz) = 159 / √ (LC)

where L is the inductance inµH and C is the capacitance inpicofarads (pF).

A choice of 100pF or 150pFtuning capacitor would allow allHF bands to be covered. It wouldseem that all of the HF amateurbands, 1.8 - 29.7MHz, could becovered by omitting the 22µHcoil and using only three of theabove coils, but inclusion of thiscoil would in practice ensurethat the bands were not at theextreme ends of the tuningscales.

CONSTRUCTIONHOME PRODUCED COILSwound on 25 - 19mm diameterPVC formers have close-woundsingle windings, with their wireends secured by threadingthrough two small close-spacedholes drilled at each end of thecoil former. 7.1mm coil formerscome complete with soldering

anchor-tags for the windingends. Note that the inner ferritecore must be purchasedseparately. The choice of atwo-pole rotary switch allowsthe individual tuning coils to bemounted directly onto the switchfor self-support. If pre-mouldedRF inductors are used as thetuning coils, they are smallenough to be mounted onto amidget wafer or miniature rotaryswitch. The more substantialstandard metric rotary waferswitch should be used to supportthe larger hand-wound coils.The choice of a six-way switchallows for the possibility ofextending the frequency-bandcoverage at no extra cost.

Coil tails should be kept asshort as possible, preferably notexceeding 10mm, and thediode, resistor and wires shouldbe self-supporting andreasonably rigid. Fig 3 offersguidance for assembly of thewavemeter.

Any form of metallic enclosuremust be avoided. It is essentialthat the coils of the wavemetermust not be screened from theincoming RF electromagneticwaves. The simplest approachto construction would be theuse of a low-cost plastic projectbox, with the tuning capacitor,range switch and metermounted on to the detachablefront panel.

For economy, a survey of thekitchen cupboard might wellyield a suitable container.Indeed, the prototype was

PVC FORMER OF OUTSIDEDIAMETER 25mm

L(µH) No of turns Span(mm) SWG2.2 9 9 2010 24 24 2022 44 44 20100 110 60 26


2.2 10 10 202.2 9 5 2610 32 32 2010 24 12 2622 63 62 2022 41 21 26100 134 70 26


2.2 11 11 202.2 9 5 2610 35 34 2010 25 13 2622 68 67 2022 44 22 26100 157 79 26

COMMERCIAL THREADED - INNER COIL FORMER OF 7.1 mmOUTSIDE DIAMETER AND 28mm LONG

L(µH) No of turns Span (mm) SWG2.2 28 14 26 without ferrite core10 60 in 2 layers each of 30t 26 without ferrite core22 80 in 2 layers each of 40t 26 without ferrite core100 80 in 2 layers each of 40t 26 with core 2/2 entered

Table 1: Close-wound coil values

Table 2: Close-wound coil values



constructed in a clear plastic,Ferrero Rocher chocolate boxof 145 x 70 x 70mm and itlooked quite elegant! Self-adhesive paper labels can beused for the tuning scale andrange switch legends.

Fig 3 shows a tuning scalewith bands marked on it, butthis should be taken only asguidance because eachwavemeter will need to beindividually calibrated.

WAVEBANDCALIBRATIONFOR THE METER to be of anyuse it needs to be calibrated.

This can be done with an HF/

VHF signal generator. This iscoupled to the meter with asingle-turn loop of wire at theremote end of its output cable,which is brought into closeproximity with the end of thewavemeter’s selected coil.

The radio station transmittercould be made to radiate a lowpower signal on each of theamateur bands while thewavemeter is tuned formaximum indication on theappropriate range, and its tuningscale marked for each frequencyband. When using thetransmitter for this purpose, it is

Fig 3: Suggested front Panel and component layout.

COMPONENTS LISTR1 2k2 0.125W carbonC1 1000pF miniature ceramic 50VL1 100µH or home-wound, see textL2 22µH or home-wound, see textL3 10µH or home-wound, see textL4 2.2µH RS 228-129 or home-wound,see textD1 Signal diode OA91 1 N4148, orsimilarM1 Volume level or battery level meter,circa 100µA FSDS1 Rotary wafer switch 2-pole 6-way,midget, miniature or standard Electronicsproject box, plastic, approximately 150 x80 x 50mmAll components for this project (less themeter) can be obtained from JABElectronic Components, 1180 AldridgeRoad, Great Barr, Birmingham B44 8PB.

important to use a dummy load.Remember that the

calibration marks now on thewavemeter tuning scalerepresent frequency bands,not precise frequencies.

Finally, for those who mightwish to experiment withextending the frequency rangeupwards to VHF, the 50MHzband could be included byfixing an addit ional self-supporting coil of 20SWGenamelled wire using 3 turnsof 25mm ID or 4 turn off 19 or20mm ID, or 12 turns of 71mmID.

C RSGB DY330

Advertisement


Book ReviewRSGB

THE AMATEURRadio OperatingManual is one ofthe RSGB’s most

popular books. The first editionwas published in 1979 andquickly became a best-seller.But times change, and such abook requires updating fromtime to time. The fourth edition,again edited by Ray Eckersley,G4FTJ, was updated during thecourse of last year and hasrecently been published by theRSGB.

For the first time, this newedition includes features ondigital communications,microwave bands DXing, 2metre direction finding (or‘foxhunting’), fast-scan TV, andEME (moonbounce operation).Even if you have no intention oftrying to bounce your signals offthe moon in order to get yourUHF signal to the other side ofthe world, the techniquesinvolved do make fascinatingreading!

Other aspects of operatingwhich appeared in earliereditions of the book have nowbeen brought right up to date inthis new edition. These includeusing computers in theshack - forexample

for keeping your log, or forcontest operation - andoperating from abroad underthe terms of CEPTRecommendation T/R 61-01.This is the piece of legislationwhich allows full Class A and Bamateurs to operate from othercountries in Europe and as faraway as Peru and New Zealand,with the minimum of formalities.Nevertheless, there are stillplenty of pitfalls for the unaware,and the Amateur RadioOperating Manual covers allthese concisely and clearly.

The scope of the AmateurRadio Operating Manual isimpressive to say the least. Itschapter headings give a clue tothe wide range of subjectscovered: The Amateur Service,Setting up a station, Operatingpractices and procedures, DX,Contests, Mobile and portableoperation, Amateur satellite andspace communications, Datacommunications, Imagetechniques, Special-eventstations.

The 10 chapters give adetailed insight into the ‘secrets’of almost all the areas ofoperating in amateur radiotoday. It is an amazing thoughtthat the 29 authors andcontributors to this book havegetting on for a thousand yearsof amateur radio operatingexperience between them!They provide for the readeralmost every conceivablepiece of knowledgerequired for operating onthe amateur bandstoday - HF, VHF, UHFor microwave.

Following these165 pages, thereare 80 pages moreof Appendices,

which include:Continental and regional

maps with the amateur radio

prefixes and the CQ and ITUzones; an IARU locator map; acallsign list which gives the ITUprefix allocation, normalamateur prefix, country name,continent, zone numbers andbeam heading from the UK; aDXCC countries list, including amulti-band checklist for the userto fill in; recent amendments tothe DXCC countries list; aworldwide time table, the officialAmateur Service frequencyallocations published by the ITU,complete with footnotes, foreach of the three ITU Regions;a list of standard frequencystations; how to conduct phonecontacts in French, German,Italian and Spanish; the bandplans; and lists of beacons, UKrepeaters, packet mailboxesand nodes.

The book is not a technicalmanual; it is about amateur radiooperating and it stresses goodoperating practices throughout.All amateurs should be awareof these, and not just beginners.The Amateur Radio OperatingManual is written in an easy-to-understand style, with confusingjargon cut to a minimum.

For beginners (and who isn’ta beginner in at least some ofthese subjects?!) there is somuch to learn about amateurradio, which is one reason whyit is such a fascinating hobby.The Amateur Radio OperatingManual goes a very long way toproviding ‘the knowledge’ whichwill help to make you an expertin at least some of the manysubjects covered.

There are very few books ofwhich it can truly be said “everyshack should have one”, but theAmateur Radio OperatingManual is certainly one of them.

[Now turn to page 23, whereyou have a chance to win acopy of the Amateur RadioOperating Manual - Ed]

Amateur Radio Operating ManualThe AmateurRadioOperatingManual, editedby RayEckersley,G4FTJ, isdescribed byRSGB HQ Staff

The Amateur RadioOperating Manual,252 pages, 273 x

200mm, softcovers.Price £10.40

(members) (£12.23non-members) from

RSGB Sales.Published by theRadio Society of

Great Britain,Lambda House,

Cranborne Road,Potters Bar, Herts

EN6 3JE, ISBN1 872309 34 8.


RSGB Diary

SEPTEMBER1 Bristol Radio Rally & Computers and Electronics Market. Details

01275 834282.

1 Milton Keynes & DARS Radio Fayre. Details 01908 672920.

1 Telford Radio Rally. Details 01743 235619.

2 Slow Speed Cumulative Contest, 1900 - 2030UTC, 80m CW.

3 144MHz CW Cumulative Contest, 2030 - 2300LOCAL.

7 AGCW Straight Key Party Contest, 1300 - 1600UTC, CW.

7 Wight Wireless & Computer Rally. Details 01983 567665.

7 / 8 144MHz Trophy, 1400 - 1400UTC, All modes.

7 / 8 All Asian DX Contest, 0000 - 2400UTC, SSB.

7 / 8 IARU Region 1 SSB Field Day, 1500 - 1500UTC, SSB.

7 / 8 LZ DX Contest, 1200 -1200UTC, CW.

8 4th 144MHz Backpackers Contest, 1100 - 1500UTC, All modes.

8 24GHz Cumulative Contsest, 0900 - 2100UTC.

8 Lincoln Hamfest. Details 01522 525760.

8 Middle Wallop Boot Sale. Details 01264 391383.

10 Slow Speed Cumulative Contest, 1900 - 2030, 80m CW.

14 Ballymena ARC Annual Rally. Details 01266 659769.

14 /15 European DX Contest, 0000 - 2400UTC, SSB.

15 BARTG Rally. Details 01394 420704.

15 Central Lancaster Radio Rally. Details 01524 64239.

15 East of England Rally. Details 01733 331211.

18 144MHz CW Cumulative Contest, 2030 - 2300LOCAL.


21 RSGB HQ Saturday Opening and Car Boot Sale. Lambda House,Cranborne Road, Potters Bar, Herts. 10am to 4pm. Details fromMarcia Brimson, 2E1DAY, on 01707 659015.

21 Scottish Amateur Radio Convention. Details 0141 773 2882.

21 / 22 Scandinavian Activity Contest, 1500 - 1800UTC, CW.

21 / 22 Weinheim VHF Convention. Details ++49 6207 3311 (during officehours).

22 Poole Radio Society National Novice Contest, 1400 - 1600UTC.For full details see page 10.


28 / 29 Scandinavian Activity Contest, 1500 - 1800UTC, SSB.

29 10GHz Cumulatives Contest, 0900 - 2100UTC, All modes.

OCTOBER1 1.3 / 2.3GHz Cumulative Contest, 2030 - 2300LOCAL, All modes.


4 - 6 Christian Amateur Radio Conference. Details 01474 533686.

4 - 6 RSGB International HF & IOTA Convention. Details 01707 659015.

5 1.3 / 2.3GHz Trophies, 1400 - 2200UTC, All modes.

5 / 6 VK-ZL-Oceania Contest, 1000 - 1000UTC, SSB.

5 / 6 432MHz - 248GHz IARU, 1400 - 1400UTC, All modes.

6 21 / 28MHz Contest, 0700 - 1900UTC, SSB.

6 Belgian 3.5MHz ON Contest, 0600 - 1000UTC, SSB.

6 Blackwood & DARS Rally. Details 01495 227550.

6 Great Lumley Radio Rally. Details 01207 237927.

9 432MHz Cumulative Contest, 2030 - 2300LOCAL, All modes.12 / 13 VK-ZL-Oceania Contest, 1000 - 1000UTC, CW.

13 Belgian 3.5MHz ON Contest, 0600 - 1000UTC, CW.

13 Computercations 96 Computer / Radio Rally. Details 01803 522216.

13 Kidderminster & DARS Rally. Details 01384 894019.

13 North Wakefield Radio Club Rally. Details 01924 827572.

16 1.3 / 2.3GHz Cumulative Contest, 2030 - 2300LOCAL, All modes.

18 / 19 Leicester AR Exhibition. Details 0116 287 1086.

19 RSGB HQ Saturday Opening and Car Boot Sale. Lambda House,Cranborne Road, Potters Bar, Herts. 10am to 4pm. Details fromMarcia Brimson, 2E1DAY, on 01707 659015.

19 / 20 Worked All Germany Contest, 1500 - 1500UTC, CW / SSB.

20 RSGB 21 / 28MHz Contest, 0700 - 1900UTC, CW.

24 432MHz Cumulative Contest, 2030 - 2300LOCAL, All.

26 / 27 CQ World Wide DX Contest, 0000 - 2400UTC, SSB.

27 1.3 / 2.3GHz Fixed Station Contest, 1800 - 2200UTC, All modes.

27 Hornsea ARC Club Rally. Details 01964 532588.

27 Tyne & Wear Repeater Group Annual Auction. Details 0191 388 2913.

28 144MHz CW Cumulative Contest, 2030 - 2300LOCAL, CW.

31 1.3 / 2.3GHz Cumulative Contest, 2030 - 2300LOCAL, All modes.

29 70MHz Trophy, 0900 - 1500UTC, All modes.29 Harlow & DARC Rally. Details 01279 832700.

29 Three Counties Radio Rally. Details 01905 773181.

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