Cockenzie & Port Seton

Amateur Radio Club Elements

Cockenzie & Port Seton

Amateur Radio Club is

affiliated to the Radio So-

ciety of Great Britain and

holds the call signs

MM0CPS and GM2T which

are used for our special

event and contest entries.

The Club was formed by

Bob Glasgow GM4UYZ in

1984, to help the local am-

ateurs get to know each

other.

Far from being just a local

club we have members

regularly attending from

the Borders, Dumfries,

Strathclyde, Fife and New-

castle.

The Club meets on the first

Friday of every month

(Second Friday of January)

in the lounge of the

Thorntree Inn on the old

Cockenzie High Street from

7pm till late.

Editorial That’s it then folks, we are now in official British Summer Time so we can all look for-ward to those long sunny lazy days where we can play at radio. Well it is a dream isn’t it! No doubt our sum-mer will be as normal, a couple of sunny days and the rest pouring with rain, but we can dream of the opposite can’t we.

OK then what has happened this month. Firstly John MM0JXI announced that he had applied and we have obtained another BT Community Champions Award to the value of £110. BT runs these awards as an encour-agement to their staff to help with a Com-munity Event and apply for funding to help make it happen. We have been successful on previous occasions where the money has gone to help with Club Activities...Training, Contesting, etc.

On the training front my Advanced candi-dates sit their Advanced exam on Wednes-day night 6 April so I know you will join with me and wish them all the best. I am sure they will all be successful. I had hoped that was going to be my last course before my sabbatical but I have been asked to run another Foundation Course to help some Air Cadets get their Communica-tion Badges. Their exam will be on Saturday 30th April so I wish them all the best with the exam. After that I am taking my sabbatical and will start up again my next training program in September, still to arrange dates. I am ready for the break I can assure you…..

Overall the entire last training program has been very successful and congratulations to

all who have passed their exams. Next the only event which is about to take place as I write this is the talk by Malcolm Gibson MM0YMG on “Emergency Communi-cations in the Community”. I am sure it will have been a very informative talk.

To this month, we have the 10 Pin Bowling Night, which I am sure, will be good night of fun. Tonight is the last night for you to de-cide and pay if you want to take part so please let me know ASAP please?

We are soon moving into our outside activi-ties with our DF Nights, Special Events and Contests. Each category offers something different so for those of you who have never done any of these types of events then now is your opportunity. DF Hunting as an exam-ple sounds easy but I can assure you it is not, especially in East Lothian where you get so many erroneous signals. Why not come and see this for yourself.

Special Events offer a chance to sit down at station that you just dream about and do a bit of operating. Prepare yourself for a pile-up then work it at your leisure. Great events as well to promote the club and what we get up to.

Lastly, Contesting, if you want to have a go then we will encourage you. See large VHF and HF stations being put together, definite-ly the ultimate amateur’s dream stations. See them in action and even take part.... they are challenges, sometimes you do well, sometimes you do not for whatever reason but enjoy the fun of just participating. I will add you will find with contesting you either

(Continued on page 2)

In this issue

6m News P.2

So you have now got a licence... P.3

Auroras P.4

No room for an HF antenna? P.6

MM0YMG Talk, Clublog Table P.8

Test Your Knowledge P.9

The Maidenhead Locator P10

Events Column P.12

V o l u m e 1 9

Ap r i l 2 0 11

04

love it or you will hate it, there are no half measures.

Continuing on, and I know this is a regular plea and you will be fed up reading it but we are desperate for material for the newsletter. I am really, really struggling each month to find material for input so can you help please. I have had lots of people offer but nothing materialises so please, please try and put something together and submit it to John MM0JXI it will be greatly appreciated.

Remember without material then there is no newsletter... as I say, sorry for harping on about it but needs must....

That is it then so hopefully you will come along to the all the events and have a great month on the radio. See you all then.

Bob GM4UYZ

(Continued from page 1)

6m News

Sunspot News In 2008-2009, sunspots almost completely disappeared for two years. Solar activity dropped to hundred-year lows. Earth's upper atmosphere cooled and collapsed and the sun’s magnetic field weakened. Researchers believe they now know why. You can read the reason why here http://1.usa.gov/fEqRWL However, the good news is that recently there has been substantial increase in sun-spot activity. Big sunspots 1164 and 1166 have been so large, they have been observed at sunrise and sunset when the sun is dimmed by clouds and haze. The dark cores of these regions are many times wider than Earth, so they are conspicuous even from a distance of 93 million miles. Several class C flares have also been observed and as this newsletter is being sent to you a Coronal Mass Ejection is en route to Earth and is due to arrive on March 6th bringing the possibility of an Aurora in the high latitude sky.

Deliberate QRM (DQRM) The evidence of DQRM on the HF bands is all too evident. Just a few minutes listening on 14MHz, especially when a dxpedition station is operating, will reveal many instances of: - Stations tuning up over the dx station Stations not listening and calling on the re-ceive frequency of a station working split fre-quencies and possibly the most unpalatable behaviour of all: Deliberate jamming by stations who either have not been heard in the pile up, or object

to the DX station calling for a particular area, prefix or power level. This occurs in addition to just plain bad oper-ating practice. Whilst six metres does suffer a small amount of DQRM it is easy to cause QRM accidentally due to the propagation mechanisms of the 50 MHz band. To minimise accidental QRM please ensure you adhere to the current bandplan adopt the best operating practice published by UKSMG and embrace the DX Code of Conduct. Applying these practices will lead to every-body working more dx during openings and less deliberate and accidental QRM.

Reproduced with permission from the UKSMG News

The Club

The Club is run in a very

informal way, just a group

of like minded people doing

something they enjoy!

This does not mean that we

don’t do anything, we enter

(and win!) contests, train

newcomers, hold talks and

video nights and run a pop-

ular annual Junk Sale. Our

newsletter has won the

Practical Wireless ‘Spotlight’

competition on several oc-

casions.

The Club supports the

British Heart Foundation in

memory of a member who

died from heart disease by

donating the profits from

some of the events we hold,

we have raised over

£14,795 since 1994.

Supported by

BT Community Champions

The normal question is, “what radio should I buy and what aerial do I need?” To be honest it is the thousand dollar ques-tion. It really depends on what you want to do, Are you inter-ested in VHF or HF? What modes do you want to use, etc., etc.? All the decisions really are answered normally in many, many cases by one’s financial situation. Anyway all the above are a topic on its own right and will leave for another day.

The decision has been made on the radio and antennas so now it is down to the operating as, let us be honest, we all obtained our licence so that we can communicate with others whether it is a few miles away or at the other side of the world. Again decisions start, do I just want to rag chew? Do I want to get involved contests and what they offer? Well the answer is— why not combine the both. Ok I know some people will already be saying but “you love contests but they are not for everybody”, I agree whole heartily with that statement but where I am aiming is as part of your communication, why not set some targets and aim go for certain awards. More on the-se shortly. What I am trying to get over is that here you are a new licen-see and probably terrified to go on the air in case you make errors and make a fool of yourself and more than likely stuck for what to say. Every amateur expects in a QSO what is called the “rubber stamp” i.e. name, QTH, RST, what radio, what antenna so they will be passed. Now what do I say next? well this is where aiming for some sort of award helps as you could be interested in DXCC countries, USA states, USA Coun-ties, German DOK’s, worldwide locators IO85MX), etc, etc. This then leads to ask the question as part of the QSO on in-formation that you are looking for. From experience it has led onto some lengthy QSO’s well and truly breaking the “conversation ice”. To give you an example of this, when I was first licensed back in 1983 I got interested in working Russian Oblasts (a Russian Oblast is an area within Russia equivalent if you want to our counties), why oblasts well it was after reading an interesting article in the SWM (Short Wave Magazine).

If I remember correctly there were about 150 in the old Rus-sian structure and each area was given a number, today after the restructure there are 92 areas each starting with two letters and then each area is broken down to further areas each starting with two numbers. The difference it made to the QSO was terrific and everyone was intrigued to why I was asking and as the result of this ended up with some long QSO’s. You also have to remember at this time the Cold War was in progress so it even broke those barriers down. These days I have started asking for the person’s worldwide locator as from what is given I can work out exactly where they are in the world down to a 1km square plus get the distance they

are actually from my QTH. A couple of examples, but hopeful-ly it illustrate the point.

As you can see from this short article by deciding on some sort of award scheme of which there are hundreds, can add a little something to the QSO. It has certainly helped me enjoy some interesting QSO’s plus at the same time learn more about different areas within the world.

http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=530

The above link will take you a page where you can select a country and find out what awards are available for that coun-try. As you will see there are many.

I also have a book called “Amateur Radio Awards” by Chris Henderson G4FAM published by the RSGB. The edition I have is the third edition 1988. It no longer appears in the RSGB’s bookshop so it looks like it may have been discontinued. If anyone is interested in having a look then I could bring it along to a club night, just let me know.

Enjoy your QSO’s and award hunting…………

Bob GM4UYZ

SO YOU HAVE NOW GOT A LICENCE….

Club Attire

The club has a design for

Club Tee-shirts, Polo-

shirts, Sweat-Shirts, Fleec-

es and Jackets and all of

these can be obtained

from the address below.

When making an order

please quote ‘Cockenzie &

Port Seton Amateur Radio

Club’ as this will ensure

that the Club Logo will be

placed on the required

ordered garments.

If you wish to add your call

-sign to the logo then

please ask at the time of

the order.

Cost will depend on gar-

ment and should cover the

garment and logo, call-sign

addition will be extra.

Order from:

PATRICIA BEWSEY DESIGNS,

UNIT 11,

FENTON BARNS RETAIL

VILLAGE,

FENTON BARNS,

NORTH BERWICK,

EAST LOTHIAN

EH39 5BW

Tel/Fax: 01620 850788

Mobile: 07970 920431

One of my favourite quotes is from a book about Auroras: “The place where the electro-jets meet on the dark side of the earth is at the Harang Discontinuity.”

It refers to a technical aspect of studying au-roras (or is it aurorae?), and is suitably confus-ing to be able to drop into any conversation and stop it dead!

But what are auroras, and why of interest to the radio amateur?

Auroras have been around longer than man, but a source of interest to scientists since the 1600s, and radio enthusiasts since the 1930s, but much more seriously since only 1957, and even now, not fully understood by anyone.

This phenomenon of the shimmering curtain of light in the northern sky known as Aurola Borealis, is mirrored by Aurora Australis in the southern hemisphere. The light is caused by electrons in the atmosphere being excited by radiation such that they emit light. The fre-quency of light (colour) is controlled by the atoms whose electrons get excited (eg oxy-gen, nitrogen etc). But the fact of these excit-ed electrons in air (or ionised gasses) is of

interest to the radio amateur because they also reflect radio waves, and that fact has, since 1957, meant an increasing number of amateurs using this reflector in the sky to bounce vhf radio signals off to increase the distance covered.

Sunspots.

We learn in the various levels of radio theory courses, that radio signals are affected by the sun, and particularly during periods of more sunspot activity. Different levels of the iono-sphere can be caused to be either reflectors or absorbers of radio signals, and that a signal directed up to that reflector will come down again somewhere part way round the earth. That’s HF propagation, and without it there’d be no DX.

But we also learn that VHF signals just keep going through it all, unless bent (refracted) back to earth in the low atmosphere (troposphere) by some sort of density varia-tion caused by weather systems. (Hence “tropospheric propagation”, often encoun-tered during high pressure).

An aurora is an area of ionisation that is so

Auroras

intense that it will also reflect VHF signals in a similar way to how HF bounces off the ionosphere. The height at which auro-ras happen is much lower than those layers we learned about (F , E, D layers etc.). Its obvious that a lower “mirror in the sky” will reflect a signal a shorter distance than a higher one. So Auroras are shorter range use than HF.

Sunspots, solar flares, plasma ejections, coronal holes, promi-nences, filaments are all terms for various activities on the sun’s surface. It is now thought that its not a direct stream of electron streams from the sun, rather that these electrons get caught up in the earth’s “magneto-tail” – a stream of magnetic field lines on the dark side of the earth. So its not directly the suns activity that causes them, but an indirect effect triggered by sun activity.

To try to simplify the physics involved in the cause of auroras is beyond most of us, but suffice to say that when the sun ac-tivity is suitable, an aurora is caused by energy and magnetic variations coming into the atmosphere causing excitation that sometimes causes light emission, sometimes causes radio re-flections, sometimes both.

Diligent recording of the triggering events by both amateurs and scientists has resulted in several common sets of condi-tions that mostly occur. Knowing them can be used to know what can be achieved by the amateur.

Frequency range? 25- 900MHz, with best Amateur bands be-ing 50, 70, 28, 144 MHz, approximately in that order of best results.

When ? In monthly terms, activity peaks in February to April and again July to October. Dips are in Jun ands Dec. In 24 hour terms, strongest auroral effects are from 1500- 2000, then a dip and another peak from 0000 – 0200. The dip in between is sometimes called the “Harang Discontinuity”.

Where? To the north! (point beams due north round to about 60deg.)

Predicting auroras: Higher sun activity including high solar wind speeds, magnetic disturbances, and best indicator of all, HF fadeout.

How far? Contacts have been made from a few hundred km to 3000km. Most common is 500-1200 km.

Visible or radio ? No straight answer here. Some good radio auroras are not visible, some area.

Power? As much as you can manage (within your licensing terms of course ! J), but much under about 25W doesn’t do much.

Antenna. As high a gain beam as possible, but sometimes a vertical works.

Operating Auroral propagation.

If you have seen a visual aurora, you will have noticed that it’s a moving lightshow. Actually it’s moving very fast, hundreds of km/hr in some cases. So if the reflector in the sky is moving, then it will distort the reflected signal. You know what you hear when a car drives by tooting its horn? The sound alters pitch (frequency). That effect is called the Doppler Effect. Ac-tually the change in frequency can be measured and the speed of the reflector calculated. It’s a pity, that fact of physics, as all radar type speed cameras use it. But from the auroral view-point, the speed is great enough to alter a radio frequency, but by a variable amount. This distortion is unavoidable, but means that voice communications are difficult. Possible though, with slow clear speech to copy that distorted hissing voice from a signal bounced off a shimmering moving curtain of light in the sky. CW is better, though don’t expect a pure tone, rather you’ll hear a hiss. ssst st ssst st ssst ssst st ssst. (CQ). This distortion increases with frequency, so 50MHz voice is very possible, 432MHz impossible, 145MHz difficult. If you use voice, use phonetics and as few words as possible. Callsign, report, locator is all you’ll manage usually. Confirma-tion with “R”, or “Roger”.

So, knowing a little about this unusual propagation mode now (no-one really understands it all, even the scientists) might encourage you to try it. Here in Scotland we have a geographic advantage. The ideal location is Shetland, but its possible to be north of the aurora (wrong side of the mirror!). The more in-tense the aurora, the further south the contacts will be. So next time you see some northern lights, remember, turn the VHF radio on and see what’s about. You might even hear me there. I hope to hear you!

Geoff MM5AHO

References and further reading: The VHF/UHF Book, Ed Ian White G3SEK; Radio Auroras. Charlie Newton, G2FKZ.

No room for an HF Antenna?

One of the hardest things to decide when setting up a home amateur radio station is what antenna to use, and where to put it.

We’d all like an antenna farm with several towers, mono-band yagis, foursquare vertical arrays etc, but most of us don’t have the space, or we’re scared of what the neighbours might think or do.

Here’s a selection of ideas, culled from various designs gath-ered over years. They are all tried and tested, and can bring surprisingly good results. They’re not the ultimate antennas any of them, but easy to make, wire antennas that work. They have a low visual profile, so neighbour complaints should be few.

The Dipole.

Dipoles can take many shapes and there are some varieties too, (see sketch)

It is perhaps the most popular wire antenna in the world.

Dipoles are normally a half wave from tip to tip.

Frequency Length

28.4 16ft 6 in 5.03m

24.9 18 ft 10 in 7.74m

21.1 22 ft 2 in 6.75m

18.1 25 ft 10 in 7.87m

14.1 33 ft 2 in 10.11m

10.1 46 ft 4 in 14.12m

7.1 65ft 11 in 20.09m

3.6 130 ft 39.62m

1.8 260 ft 79.25m

How you arrange the dipole is less important that many think.

Can’t get it all in a straight line? The run it round a bend. It will still work. Can’t get the whole length up horizontal? Let the ends droop down, its OK.

Want more bands? Join several dipoles together, sometimes called a “nest of dipoles”.

Inverted V This is a variation on the dipole, and is very useful where only one suspension point is possible. The coax feed is at the apex, with centre to one side and braid to the other side. Each side of the V terminates near the ground. It’s not important if its not exactly at the ground, nor that each is the same distance from the ground. Just go where you can fit it.

An interesting variation on this is to arrange two inverted Vs at 90 degrees to each other (still from a single pole, like guys in 4 directions). These are covering two bands, one each, so you have a 2 band Inverted V.

A suitable pole for the Inverted V might be a tree. If so, then remember to give the low ends some flexibility. One way is to use a bungy, or even pulleys and weights.

(Continued on page 7)

Loop Skywire This antenna requires four suspension points. These might be trees, buildings, fences, whatever. The higher the better, but use what you’ve got.

It’s an elevated square of wire, fed from one corner (see sketch). It lies horizontal, parallel to the ground. The performance is best when the area of the loop (as seen from above) is maximum. Theoretically that means a circle, but that’s requires many suspension points. Much easier is a square. If you stretch it to a diamond, that’s OK, but keep the area as big as possible. Any copper wire will do, but to keep it high and tight, lighter weight wire will sag less.

Height of about 40 ft is best, but do what you can. It’s not criti-cal.

The length depends on the frequency you want. For 80m band use 272 ft; for 40m 142 ft.

160m Sloper

If you have any trees nearby, you could consider this sloper. It’s a reduced size one using only 1/8 wavelength (68ft) of wire.

To erect it, put a rope up a tree as high as you can (about 40 ft, but on a branch strong enough).

This second sloper has a loading coil to make. Its not complex, (see sketch).

A piece of ¾ inch plastic pipe of about 26 inches long has a 90 turn coil of 16 gauge wire wound into a coil of about 4 ½ inch-es long. Keep the windings tight. Wrap the windings with insu-lating tape, joining one end to the wire of the antenna, the other end to the coax centre. The braid needs a wire to drop

to earth where you will arrange some radials. The length isn’t critical, but make them as long as you can, and as many as you have wire for. If they’re not straight it doesn’t matter.

This antenna, though short can produce some good results. The 160m band is an interesting one and contacts around Eu-rope should be possible, perhaps further in good conditions.

Geoff MM5AHO

(Continued from page 6)

Thanks to the sterling

work by M0RNR, our club

has been added to the

excellent Clublog system

developed by Michael

Wells G7VJR.

www.clublog.org

The system allows mem-

bers to upload their logs

in ADIF format and have

them displayed in a table

with all the other club

members.

Clublog also has great

facilities for tracking your

DXCC status etc so is well

worth taking the time to

register and get your log

uploaded.

To update your log with

the next set of contacts

you can simply upload

your whole log again and

the system will take care

of the duplicates. Alterna-

tively you can export the

bits you want from your

own log and just upload

that.

The tables we’ll publish

here will be the club, fil-

tered by the current year,

so everyone starts a new

year at 0 contacts.

Rank Callsign 160 80 60 40 20 17 15 12 10 Total Slots Range

1 GM4IKT 0 0 0 6 73 5 56 0 12 113 152 7 yrs

2 M0RNR 0 8 0 39 50 0 17 0 0 65 114 12 yrs

3 MM0XXW 0 0 0 28 39 15 12 0 0 49 94 5 yrs

4 GM4UYZ 0 4 0 2 29 0 19 0 0 39 54 31 yrs

5 MM0WZB 0 1 0 8 9 4 1 0 0 16 23 1 yrs

Clublog Table

Malcolm MM0YMG gave a presentation on

Emergency Communications in the Communi-

ty.

He started out by outlining the history and

function of RAYNET and then went on to

demonstrate some of their procedures for

speedily establishing a network and how mes-

sages from User Groups are passed . Malcolm

then described the equipment used by

RAYNET and the concepts of resilience and

preparedness (having backups for almost eve-

rything and keeping a grab bag ready for in-

stant use when called out).

RAYNET get practice for their emergency role

by providing communications at events like

Endurance horse riding where they set up

networks over long distances in often difficult

terrain and keep then running for as long as is

required.

Malcolm then went on to describe the Lothi-

ans 4x4 Response group who use their 4wd

vehicles to provide transport and assistance

to local community groups in times of bad

weather. He described their activities during

the recent spell of heavy snow over Christmas

where members of the group travelled over

10,000 miles and assisted hundreds of people.

Although, not part of RAYNET, the radio pro-

cedures and training used there is useful to

this group too as many members have Ama-

teur Radio Licenses.

Malcolm concluded by describing how his

Landrover is kitted out for RAYNET and L4x4R

duties.

The talk was very well attended, so thanks to

everyone who came along and to Malcolm

MM0YMG for an very interesting talk.

John MM0JXI

Talk: Emergency Communications

Test Your Knowledge

1. 51 MHz is in the

a. HF band

b. VHF band

c. UHF band

d. microwave band.

2. In which stage of the transmitter is the signal from the microphone placed on the radio carrier?

a. Modulator

b. Audio amplifier

c. Antenna

d. RF amplifier.

3. A new desk microphone is plugged into the trans-mitter, replacing the hand microphone supplied. What control or adjustment should be checked?

a. Transmit frequency.

b. Mode.

c. Microphone gain.

d. Receive audio volume.

4. To which part of a radio receiver is the antenna lead connected?

a. Loudspeaker.

b. Audio amplifier.

c. Tuner and rf amplifier.

d. Detector.

5. The output from a transmitter should be connected to the antenna by

a. waterproof mains cable

b. screened audio cable

c. bell wire

d. coaxial cable.

6. Effective Radiated Power (e.r.p) is the

a. actual transmitter power

b. transmitted power after loss in the feeder

c. power to the antenna multiplied by the antenna gain

d. reading on a power meter in the output lead.

7. The SWR on a feeder is related to the

a. transmitter power

b. received signal strength

c. diameter of the feeder

d. power reflected at the antenna.

8. Radio waves

a. will stop when meeting an antenna

b. cannot be reflected

c. tend to travel in straight lines unless reflected or diffracted

d. can be stopped by any solid object.

9. The layers of conductive gas at heights from 70 to 400kM used to reflect hf radio waves are called the

a. hemisphere

b. bathysphere

c. ionosphere

d. atmosphere.

10. A domestic or amateur receiver may suffer interfer-ence from

a. a CD player

b. an electric clock

c. an electric drill

d. a filament light.

I wrote the article below in 2009 and I thought I would resur-rect it to help the newcomers that have come into the hobby who have heard the terms but don’t know what it is all about. For information I have slightly “tweaked” the original article to bring it up to date.

For those of you who took part in the Club’s 25th Anniversary Challenge the mechanism that was used to calculate the dis-tance between your QTH and your contacts QTH in kilometres was the use of Maidenhead Locators.. also know as just Loca-tor or WWL (World Wide Locator). Obtaining your contacts locator can be done either by obtaining it as part of the QSO or looking up the station’s details in http://www.qrz.com/ . If you use the latter method all I can say is beware as I have already found on at least two contacts that I made that the locator given was no where near where they are i.e. an Esto-nian contact gave his locator which put him in the Congo in Africa !!! With regard to the challenge the following link is what I am using to help calculate the distances. Use the bottom of the displayed page and insert your own locator then in the “Src Loc box” below that your contacts locator in the “Dest Loc box” then click on the “>” sign and the distance will be displayed.

The link: http://home.arcor.de/waldemar.kebsch/The_Makrothen_Contest/fmaidenhead.html

So how did the Locator system come about well read below. The information has been researched from the source, “the ARRL World Grid Locator Atlas”:

Background

In the 1950s there was a need among central European VHF and UHF amateurs for a short way of giving positions in con-tests, because the scoring was based on the distance, normal-ly 1 point per kilometre, and the so called "QRA locator", name changed in 1972 to "QTH locator", was introduced. The system used 2 letters to indicate the largest unit, "square", that was 2 degrees (longitude) * 1 degree (latitude). Without repetitions the system covered the area 0-52 de-grees eastern longitude and 40-66 degrees northern latitude.

The system became very popular and amateurs started to use it in all types of contacts, not only in contests. It also spread outside the non-repeating area and the same locator could unfortunately be found in many places. North American radio amateurs also started to show interest in the locator idea.

For these and other reasons a proposal at a meeting of Euro-pean VHF managers in Amsterdam in 1976 that we should start discussing a worldwide locator system that could replace the old one. In 1978 Region 1 of the International Amateur Radio Union (IARU) decided to contact the other regions on

this matter and Folke RosVall, SM5AGM started to collect proposals for a new system.

In October 1979 SM5AGM proposed a system starting at the principal dateline with 20 x 10 degrees large units, 2 x 1 de-grees middle units and 6 x 3 minutes small units. Two months later Folke RosVall, SM5AGM received a letter from Dr. John Morris (G4ANB), who proposed a system starting at the Greenwich longitude with 20 x 10 degrees large units, 2 x 1 degrees middle units and 5 x 2.5 minutes small units without having seen Folke RosVall, SM5AGM pro-posal. The systems were in all other respects identical.

In April 1980 a meeting of European VHF managers was held in Maidenhead, near London (United Kingdom), where it was felt that the time had come to try to find the best system out of the more than 20 proposals received so far. It was found that the best possible system was the system proposed by G4ANB, with the modification that the starting point should be shifted to the principal dateline, in accordance with what had been proposed by Folke RosVall, SM5AGM .

In 1982 the Maidenhead locator system was adopted by IARU Region 3, in 1983 the Maidenhead locator system was adopt-ed by IARU Region 2 and in April 1984 the Maidenhead loca-tor system was adopted by IARU Region 1 as new locator from 1985, January 1.

Description of the Maidenhead Locator System

The earth's surface is divided into 18 x 18 = 324 "fields", each one 20 degrees (longitude) x 10 degrees (latitude). Each field is divided into 10 x 10 = 100 "squares", each one 2 degrees (longitude) x 1 degree (latitude). Each square is finally divided into 24 x 24 = 576 "sub-squares", each one 5 minutes (longitude) x 2.5 minutes (latitude). The fields are indicated by 2 letters AA-RR, the squares by 2 digits 00-99 and the sub-squares by 2 letters AA-XX. The first character is the longitude character and the second character is the latitude character on each level. The numbering direction is everywhere west to east and south to north. The complete locator is the sum of all 6 characters, for example "FN43MJ". Recommended abbrevi-ation for the word "locator" on CW is "LOC".

Finding One's Maidenhead Locator

Start by finding your longitude and latitude in degrees and minutes from a local map. Then read the first 4 characters (field + square) directly from a map on the pages 4-21. Then read the fifth and sixth characters (sub-square) from the ta-bles below. Now you must be careful. Because a square is 2 degrees wide (west-east), you must observe if you are in the left part (western part) or in the right part (eastern part) of the longitude table. Please also observe that the upper parts

The Maidenhead Locator System

of the tables are for eastern longitudes and northern latitudes and the lower parts of the tables are for western longitudes and southern latitudes. This is because the locator has a con-stant direction, while longitude and latitude are changing di-rections at the Greenwich longitude and at the equator. Do not forget to print your locator on your QSL card!

Computer Program for Direction and Distance

Most computer programs for distance calculation are based on the simple model of the earth being a sphere. When used worldwide the error might reach 70 km in some cases because of the ellipsoidal shape of the earth. When used locally (within 2000 km) the error might reach 10 km depending on direction and distance.

In 1883 Jordan published a formula based on the ellipsoidal shape of the earth. The Jordan formula works well over most of the earth's surface, but at very large distances the error might reach 100 km. The Jordan formula has been used by many radio amateurs for many years.

In the end of 1984 Folke RosVall, SM5AGM decided to try to write a BASIC computer program, that gives good results be-tween any two points of the earth's surface. The maximum error for distances between midpoints of fields, squares or

sub-squares should be +/-1 km in the range 0 - 18000 km and +/-2 km in the range 18000-20004 km. Direction determina-tion for very short distances and for very long distances (near the antipode) is numerically unstable and the error will rapidly increase when going to 0 or 20004 km. Also because of the ellipsoidal shape of the earth, direction determination near the antipode is complicated. But in the range 50-18000 km the maximum error for midpoints of fields, squares or sub-squares should be +l- 1 deg.

By searching the internet there are a few programs written by different authors and it is all about choosing the correct one as there may be some slight errors in distance given by each of them.

I hope that this now gives you an idea about the Locator Sys-tem.

Bob GM4UYZ

EASTERN LONGITUDE

EVEN DEGREES ODD DEGREES

+10' +20' +30' +40' +50' +10' +20' +30' +40' +50'

WEST A B C D E F G H I J K L M N O P Q R S T U V W X EAST

+50' +40' +30' +20' +10' +50' +40' +30' +20' +10'

ODD DEGREES EVEN DEGREES

WESTERN LONGITUDE

NORTHERN LATITUDE

+5' +10' +15' +20' +25' +30' +35' +40' +45' +50' +55'

SOUTH A B C D E F G H I J K L M N O P Q R S T U V W X NORTH

+55' +50' +45' +40' +35' +30' +25' +20' +15' +10' +5'

SOUTHERN LATITUDE

Contacts

General correspondence,

training and contest en-

tries

Bob Glasgow

7 Castle Terrace

Port Seton

East Lothian

EH32 0EE

Phone: 01875 811723

E-mail:

gm4uyz@cpsarc.com

HF Contests

Cambell Stevenson

mm0dxc@aol.com

VHF Contests

John MacLean

mm0ccc@cpsarc.com

Club Tables

Bob Purves

gm4ikt@cpsarc.com

Contest Reports

Robin Farrer

mm0vtv@cpsarc.com

Newsletter, website,

event calendar

John Innes

newsletter@cpsarc.com

1 April 2011 Club Night

2 April 2011 SP DX Contest

9 April 2011 10 Pin Bowling, Tenpin, Fountainbridge 20:00

16 April 2011 Holyland DX contest

16 April 2011 GMDX Convention, King Robert Hotel, Stirling

30 April 2011 Newsletter Deadline

6 May 2011 Club Night

13 May 2011 1st 144MHz DF Hunt

28 May 2011 Newsletter Deadline

3 June 2011 Club Night

Port Seton Gala Day (Date to be confirmed)

12 June 2011 Practical Wireless 144MHz QRP Contest

18 June 2011 Newsletter Deadline

18/19 June 2011 Museums on the Air Weekend GB2MOF

22 June 2011 CPSARC 20m Activity Night

24 June 2011 Club Night (Early to avoid clashing with VHF Field Day)

2/3 July 2011 VHF Field Day

30/31 July 2011 RSGB IOTA Contest GM2T from Tiree

30 July 2011 Newsletter Deadline

5 August 2011 Club Night

12 August 2011 18th Annual Mini Rally Night

20/21 August 2011 Lighthouses Weekend GB2LBN

2 September 2011 Club Night

23 September 2011 2nd 144MHz DF Hunt

7 October 2011 Club Night

21 October 2011 Video Night

29/30 October 2011 CQWW SSB Contest GM2T

4 November 2011 Club Night

18 November 2011 Talk by Len Paget GM0ONX ‘Planning Permission’

2 December 2011 Club Night

10 December 2011 Club Christmas Night Out

Events Column Answers from April 2011 newsletter “Test Your Knowledge”.

1B, 2A, 3C, 4C, 5D, 6C, 7D, 8C, 9C, 10C