VOLUME:  3              No. 1                                                                                       JUNE 1994


CHAIRMAN’S COMMENTS                                                                                  BILL WRIGHT

ARE YOU RECEIVING US ?                                                                     PETER MACDONALD

GB2OWM  THIRD ORKNEY SCIENCE FESTIVAL                                          BILL WRIGHT

SOUND SERVICES LTD                                                                     STEWART POTTINGER

DECCA  NAVIGATOR – THE END OF AN ERA                                   TOMMY MAINLAND




     Summer has come, or at least we thought it had in May!!

     Things have been happening.  It looks as though the Trustees have managed to sort out the problem over the use of the old school; time will tell.

     Members who live in Orkney will know that problems are having to  be faced with regard to the oversight of the Museum on a day to day basis. To quote from the minutes of a Committee Meeting held on 3 February:

    "The Chairman briefly traced the history of the staffing of the Museum, noting that the death of Mrs MacDonald Snr had meant that there was no continuous oversight and that the present tenants of Viewfield had very kindly opened and closed the Museum during the 1993 season.  However there were long periods when there was no one at the Museum to keep an eye on the collection.  The Trustees being much aware of this problem had asked if the "Friends" could arrange to staff the Museum during the 1994 season, that is from April to September, opening between 10 am and 5 pm, every day."

     After discussion it was decided "..that a circular be sent to all Orkney members seeking their view on the proposals, and asking for availability."

     At a Committee meeting on 3 March the Chairman reported "that as decided at the last meeting, a circular was sent to all members in Orkney asking:-         

a)   For their views on the proposal that the Friends should staff the Museum;

            b)   Whether they would be prepared to Staff the Museum

            c)   For their availability on a regular basis.

     42 Letters were sent out on 9 February, with a response date of 23 February.

     The Secretary reported on the 12 replies which he had received.

     11 were clearly in favour of the proposal; 10 were willing to help to Staff the Museum. Of those who gave a definite date, one was possible on Tuesday or Saturday; Two, attending together, offered alternate Wednesdays; One possibly available on a Wednesday; One with spouse possibly on a Friday; One on Sunday afternoon.

     After a general discussion it was decided that the Trustees be informed:

a)   That it was apparent that the Friends could not staff the throughout the week.

     b)   That it might be possible to provide some sort of cover for 3 days viz Wednesday, Saturday and Sunday."

     The Trustees have noted the position and have suggested that willing Friends could go to the Museum as and when they were able.  To this end provision was being made for keys so that they could gain access to the Portacabin.  It might be sensible if Friends wishing to undertake this service first contact the Secretary to obtain a key and to ensure that we did not end up with a number of people going at the same time. At the moment various people are attending on an irregular basis.

                                                       Bill Wright



     This feature is to inform "Friends" of some of the events which have been happening behind the scenes during the last year, so please tune-in carefully ...

     In October 1993 the Museum was kindly gifted, what is believed to be, one of the earliest colour television receivers purchased in Orkney.  it is a Sony Model KV1800UB and belonged to Neil Foubister of Holm, who purchased it from Orkney Television Enterprise. "Friend" and proprietor of OTE, Eric McLennan, confirmed that although he was not sure of the date the television was sold, it was one of a few he brought home while colour television was still experimental in Orkney.

     After a few enquiries, Alan Windwick (ex Thistle TV) suggested that colour TV was introduced to Orkney around the end of 1975.  A visit to the Archive Department of the Library quickly confirmed this.  The first page of "The Orcadian" I examined dated January 2 1975 stated the following:-"Keelylang should be in operation at the end of the year giving colour TV on 625 lines.  At present Netherbutton was in operation with black and white on 405 lines.  The 625 line transmitter for Caithness situated at Rumster Forest has been in operation for some months.  People in Orkney have already been buying Colour televisions in anticipation of the new Orkney Transmitter and in the meantime are receiving marginal reception from Caithness."

     Eric explained "I thought I would take a chance that some people in Orkney would be able to receive a signal from Thrumster and this set was one of the first I brought home !  I also decided that I would go for a fully transistorised model from the start".

     Since the article in "The Orcadian" was published at the beginning of January 1975 it is possible that this TV was receiving colour pictures as early as 1974 and we could therefore be celebrating 20 years of colour television in Orkney this year.

     The television still had a presentable picture when we got it and is one of the few Japanese sets we have. (Perhaps a sign of things to come).

     Another "Friend" who made contact with us this year is Tommy Mainland from Dounby, who called along one day and calmly asked if I would like a Decca Station for the Museum !!  The Decca Station at that time was pending a complete modernization which would mean equipment being scrapped and fewer staff. After much deliberation at Tommy's generous offer, it was decided that it might leave us a bit tight for space, and instead we obtained the services of Harold Esson from Dounby, who kindly did a professional job of videoing the old station. (See Tommy's article elsewhere).

     Sadly we have to report the death of Ara MacDonald aged 85 in November 1993.  Mother of the Founder she helped to look after the Museum for its first five years of existence, continuing after the Founder's death.

     On the conservation front the Trustees have been making steady progress on controlling the environment inside the Museum.  Acting on the advice of Sarah Slade, (Conservation Manager of the Scottish Museums Council) we have purchased special low Ultra Violet light emitting fluorescent tubes for the overhead lighting and UV light absorbing film to put on the windows.  Ultra Violet light wavelengths are the shortest and therefore have the highest energy and most destructive effect on exhibits.  We also received a 50% Grant from Scottish Museums Council towards the purchase of a De-humidifier for the Museum.

     Local Artist Mr Jim Baikie kindly agreed to let us have the copyright over the familiar Museum Logo (Old man tuning in a wireless set); our thanks to him.

     An urgent call came from the Orkney Islands Council Buildings Services Department one day offering us the old DC electric switchboard out of St Magnus Cathedral dating from around the 1920s.  Workers were in the process of gutting out the South Transept Chapel and an answer was needed urgently.  Acceptance was made easier by the offer to deliver it to our store at the old St Margaret's Hope School.  It stands about six feet high by about five feet wide and I believe it took about four men to lift it !  Having been stored in such a good environment for so many years it is a beautifully preserved piece of equipment and full of character.  Our thanks to Jim Rousay in the Cathedral and the OIC Building Services for saving such an interesting item at such short notice.

     A familiar name in Kirkwall "John T Miller's" Filling Station at the Kiln Corner recently closed with the retirement of Jackie and Willie Miller.  Originally the business was run by their father John T Miller and had a long history of involvement in wireless over the years.  Repairs and maintenance of sets for most of these years was faithfully carried out by full time radio mechanic Bill Burgess of Kirkwall.

     They were agents for such brands as Cossor, Kolster Brandes, Vidor and Ferranti amongst others.  The Museum gained many items of interest from them over the years and Jackie and Willie kindly let us rummage through some of the remaining stock before disposing of it.  Amongst recent items of interest which they donated were glass cinema projector slide plates from the 1950s advertising their products, a pre-war Drydex battery stand, catalogues, books etc., all very scarce and desirable objects with a strong Orkney connection.  At the time of writing more items were being produced each week.  Jackie and Willie are to be congratulated on keeping all these items which are now to become part of Orkney's heritage.

     More recently, a visit was made to the Museum by two ex-Netherbutton Radar Station WAAFs and their husbands.  Margaret Renwick travelled to Orkney from New Zealand to be re-united with her friend Mabel Anderson from Finstown.  Both ladies served at Netherbutton in the years 1943 onwards, and their pictures can be seen in the Netherbutton display inside the Museum.  Mabel and husband Andy are members of the "Friends".  another ex-Netherbutton service man who also recently joined the "Friends" is Jack Brooker from Sussex.  All their stories on Netherbutton are being preserved in the Museum archives.

     Finally, the Museum intends to have a small display again this year at the Annual Vintage Club Rally at Walliwall on Sunday 14 August. We have attended this event virtually since the beginning of the Vintage Club itself.  Other small displays may take place elsewhere.  Last year's theme at the Rally was the 1950s, so I carefully planned and selected as many sets from that era as I could lay my hands on.  Feeling quite proud of my 50s display I must confess to getting a bit of a drop when one member of the public complained that she had seen "far older sets than that at home...", and another asked why  "we never showed his one ? ".  Never mind you cannot please them all !


                                                       Peter MacDonald





     At the request of the organisers of the 3rd Science Festival the Museum Amateur Radio Station - GB2OWM - was activated over the period 10 to 16 September 1993.  Operation was confined to afternoons, nominally 2pm to 5pm except for the Saturday and Sunday when there was operation in the mornings as well.  Activity was mainly on either 7MHz (40 metres) or 14MHz (20 metres) using single sideband.

     The activation of the station was publicised in the Amateur Radio Press, via GB2RS New Broadcast, and via the RNARS "grapevine".

     We took advantage of the new Portacabin, which replaced the Container, as the location for the radio equipment.  It was a considerable improvement over previous years where we have had to move the Juke Box out of the Museum Building to make room.  It was altogether a much more cosy environment for the operators and visitors alike.

     In previous years we have used a G5RV multiband dipole in an inverted V configuration using a portable 25 feet mast as the centre support.  Livestock in the field where the mast was usually erected, coupled with the fact that the site of the mast was now in the middle of the tractor track into the field and the availability of the Portacabin resulted in re-think of the aerial arrangements.  A

G5RV (in fact the same G5RV) was used, but arranged horizontally with one end supported by the usual portable mast, and the other by a "convenient" lamp post. (Thanks Mike for fitting the block and halliard to the lamp post).  This gave a height of about 25 feet at the ends with a sag in the centre.

     The equipment used belonged to the operators.  The power being about 100 watts.

     Band conditions were not too good, but 274 contacts were made in 28 countries.  Compared with last year the QSO rate was up (215) but the country score (30) was down. Most of the contacts were in Europe, including several of the new republics that did at one time form part of USSR, and both new halves of what used to be Czechoslovakia.  There were several contacts with the USA.  Many members of the Royal Naval Amateur Radio Society were contacted. Since the Museum first began operating an amateur radio station in April 1989 there have been 1231 contacts.  Quite a number of stations were worked who knew of the Museum and several where the operator had been to the Museum.

     Thanks are due to the operators, loggers and QSL card writers, including Reg, GM0CUY; David, GM0MHS; Anne GM0TLX; Robert GM1MWK; Bill, GM3IBU; Andy GM3MTS; Clive GM3POI; Alan GM4IOB; Kim GM4LNN; David, GM4TYU; Hilda, GM4ZZH; Sandy, GM6WOF; George, GM7GMC and Peter MacDonald.

     It is possible that the station will again be activated for the 4th Orkney Science Festival scheduled for 9-15 September 1994.



                                             Bill, GM3IBU



     It was on a visit to John Hourie of Heathfield, St Ola, to see some equipment he was offering the Museum, that he handed me a photograph his Mum had kept for many years.  The photograph showed six persons standing next to a van with "Sound Services Ltd" printed on its side.  The photograph intrigued me since this was obviously a fairly substantial organisation, but not one that I had heard of before.  Investigations soon led me to Stewart Pottinger, retired Garage owner from Finstown, now living in Kirkwall, who is the last surviving member of the group in the photograph.  We are indebted to him for the following information.

                                                                 (P McD)


     The two pictures shown are both taken outside what was known as the ENSA Hut which was situated where Hornersquoy Lane is now, near to the Balfour Hospital in Kirkwall.  At that time all entertainment for the troops was carried out by the organisation "ENSA" (Entertainments National Services Association).

    The ENSA Hut had an important role in the provision of entertainment for the forces since it provided the Mainland accommodation for all the visiting "Stars", such as Gracie Fields and the like, who came to Orkney to entertain the Troops,

     Sound Services Ltd headquarters were situated in a Nissen Hut below the ENSA Hut.  Their job was also to provide entertainment, but in the form of travelling film shows to the many varied army camps based in and around the Orkney Mainland and South Isles.  They were employed by ENSA Sound Services.

     The scale of their operation can be seen from one of the photographs which shows no less than five vans with five operators, all of which would be "on the road" in any one week.  The sixth person - Duncan Pottinger (Stewart's Father) - was in charge of the group at that time and carried out maintenance and repairs.  All are Orcadians.

     It was around December 1943 that Stewart, having just left school, became a travelling projectionist with Sound Services Ltd.  He was issued with an Identity Card which gave access to all the Camps.  It contained his photograph and had the following printed on it:-"Employed in essential war service by Dept of National Service Entertainment (NAAFI) as Projectionist and Technician - Sound Services."

     A typical week for Stewart would be to call in at Sound Services at the beginning of the week to collect the film he would be showing all week at the various camps.  Usually there were two shows at different locations each day.  Other equipment needed was a projector, screen, speakers and a generator in case no power was available.

     Some of the Camps visited were Deepdale Camp in Stromness, Ness battery, Crustan in Birsay, Netherbutton in Holm, Wasswick in Rendall, and North Dawn Hospital in Holm.  Trips to Flotta or Lyness would entail off-loading heavy equipment onto a boat and then back onto a lorry once the Island was reached.  Each Camp usually had a set time and day(s) for showing films to off duty personnel, so you knew that you were expected.

     Films could contain Pathe News, Cartoons or Sing-a-long.  Some of the ones that Stewart remembers were, "Me and My Girl", "Arsenic and Old Lace", and others starring Fred Astaire. 

     Drivers would have full use of their van during the working week and could take it home at nights.


(Left to right) – Duncan Pottinger, Mr Cruikshank. Alec Leask,

Jim Findlay, Stewart Pottinger, Rodney Groundwater


Ready for Action !

V3 – 1. 7



Inevitably, this all had to come to an end once the War drew to a close, although shows continued for a time until most personnel had left Orkney.

     Stewart had to make no less that three trips to London returning Sound Services' vans after the war - quite a trip in those days.

     Alec Leisk (shown in the photograph) went on to become a projectionist at the Phoenix Cinema in Kirkwall. Stewart went on to work in the Rural Cinema.  To this day, Stewart has film reels in his possession from his war time days, and some of them have been shown since.

     It is now over 50 years since Sound Services Ltd travelled Orkney in their vans providing what must have been a great morale booster for homesick soldiers.  It is good that we can record here their important role in Orkney's wartime entertainment.

                                                  Stewart Pottinger





     One could hardly escape the media coverage during the past few weeks, in connection with the 50th anniversary of D-Day.  It is, however, less well known that 6th June 1944 was also the first time that the Decca Navigator System was used.  This system, invented by an American gentleman called Bill O'Brien, had, like so many other radio devices, been developed in conditions of war-time secrecy as an aid to coastal navigation.  The first chain (presumably of three stations) was built on the south coast of England and provided accurate coverage of the central English Channel, all the way to the invasion beaches.  It was not, of course, called 'Decca Navigator' in those days.  Instead, it gloried in the title of 'Blue Gasmeter', but whether this was a code-word, or merely an indication of what the equipment looked like, is now forgotten.

     After the war, Mr O'Brien tried to raise finance in his native USA to develop the system commercially, but the US government was busy with its own Loran system and the big electronic companies weren't interested.  He therefore came back to Britain where he finally found a backer in the unlikely guise of the Decca Record Company, and so the Decca Navigator system was born.  The first chain built (the English chain, covering the eastern end of the English Channel and the Thames estuary) began transmissions (we think) in late 1946 and early 1947.  Expansion took place comparatively quickly with, in turn, the Southwest British, the North British, and finally, the North Scottish chains being built, each covering the area implicit in its name.

     The North Scottish chain was centred on Dounby (the master station), with slave stations at the Butt of Lewis, Lerwick, and Peterhead.  The first test transmissions from Dounby took place on 19th August 1955, and continuous transmissions (using equipment 'borrowed' from other chains, housed in wooden huts) began on 1st September 1955.  The change-over to permanent, purpose-built buildings and new equipment took place on 26th January 1958, and there we have stayed ever since.


Tommy Inside the Old Dounby Decca Station.


The System


     For the non-technically minded, Decca transmissions are made from groups of (usually) four stations, called chains - thus the North Scottish chain of Dounby, Lewis, Lerwick and Peterhead.  The receiver in your aeroplane or boat - or nowadays in your car or even backpack - in effect measures its distance from each of the stations in the chain.  Casting your mind back to school geometry should tell you that if you know your distance from three fixed points, you know exactly where you are.  In this case knowing your distance from the fourth point gives a further check on your position.

     For the slightly more technical minded, each Decca chain is allocated a frequency, 'f', in the region of 14.1 kHz.  The main driver oscillators on all stations in the chain actually operate at this frequency.  Each station then transmits a different harmonic of this basic frequency, the master station (Dounby), for example, transmitting 6f.  These are all unmodulated cw signals, and the net result is to set up harmonic standing wave patterns between the four stations.  The three standing wave patterns between master and each of the slaves are known as the Red, Green, and Purple patterns, form the basis of the Decca Navigator system.  Where the crests of these standing waves will occur can be accurately calculated and drawn on a chart.  Decca charts are simply standard Admiralty charts, overprinted with the three standing wave patterns, each in its own colour and with appropriate numbering.  The Decca receiver counts its way along the waves in these patterns, giving three read-outs which can be transferred to the chart, thus giving a position.

     In the old days of mechanical clock type read-outs (sorry! meters) you had to know your position to within approximately 10 miles when you first switched in the receiver, and physically set the meters to the approximate readings.  This is because the patterns repeat every twelve miles or so.  Knowing your position to within ten miles is not quite as silly as it sounds!  Decca is a short range (250 mile) coastal navigation aid.  If you were entering the coverage after having crossed the (pre-satellite) Atlantic on compass alone, not having seen the sun or stars for six days, your guestimated position could often be widely different from your actual one.  Nowadays, with all-singing, all dancing electronics, 'position acquisition', to use the buzz-word, is automatic, but the basic system of three patterns and three read-outs is as it always was.

     For the day to day running of the stations, reliability was the watchword.  Everything except the transmitting aerials was duplicated, and many of the more important bits and pieces of equipment were in triplicate.  It used to be said that if the users were aware of something going wrong with the system, then we were really in trouble.  In practice, the rare occasions when this happened were usually due to storm damage to the aerials.

     Interference was never much of a problem.  Using unkeyed cw signals as the system does, the receivers have, right from the start, had banks of crystal filters, and hence a bandwidth of the order of 100 Hz.  Any potential interference had, therefore, to be virtually on top of the Decca signal in order to cause problems, and in practice this rarely happened.

     Skywave, on the other hand, was always a problem.  Skywave occurs after dark when radio signals are reflected back to earth from the ionosphere.  One of its better-known manifestations is to greatly increase the range of a radio station - compare the babel of European stations on Medium Wave at night to the one or two British stations there during the day.  Skywave also occurs at shorter ranges and in Decca's case the (reflected) skywave signal mixes with the (direct) groundwave signal, the result being a distorted, and therefore inaccurate, standing wave pattern after dark.   What this means in practice is that a daytime Decca position, placing you somewhere in a circle of 20 metres diameter, can be degraded to a night-time position somewhere inside a circle of 500 metres diameter.  Modern electronics, such as tracking receiver oscillators with predicted slew-rate (whatever that means) have reduced the problem, but it is probably impossible to eliminate it altogether.

The Future ?

     Over the years, although the politics of the system have changed - first take-over by Racal Electronics, leading to the mouthful 'Racal-Decca Marine Navigation', and then, at least as far as funding is concerned, being taken under the wing of the General Lighthouse Authority - working on the stations has remained remarkably stable.  Now, however, automation has finally caught up with us.  Comes September, the entire UK Decca system will be unmanned, with a remote control and monitoring centre in Edinburgh.  Perhaps, on reflection, Mr O'Brien (who died some years ago) would have approved.

                                                       Tommy Mainland