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Dear OM,

There is still much to do on these homepages but it is a start. I "Grabbed" the images out of my video camera and then compressed them to save download time. For a panoramic view of the station - CLICK HERE

My late brother Roy Larsen (ZS6QU) and I, David Larsen (ZS6DN) were both amateur radio experimenters and operators. We both retired in our 60s and carried on with our amateur radio interests.

It all started on July 19th 1879 when, after the untimely death of their father, Sivert Andersen, the three grandchildren of Anders Tollevsen Salbu left Bergen (Norway) on the Sailing Ship Debora and settled in Port Natal. An important part of the mission of the Debora members was that "all would endeavour to create new economic activities" - amateur radio was to become one of the significant "stepping-stones" towards meeting this objective.

The LARSEN family finally settled south of Durban where they purchased a 1030 acre farm - lot 8 of Oribi Flats. They called the farm Fredheim. 

In the early 1900s three of Anders Tollevsen Salbu's great-grandchildren - the cousins Johan Thorvaldsen (ZS5B), Gustav Larsen (ZS5DN) and Sivert "Wireless Windy" Larsen (ZS5BE) - became dedicated radio amateurs and established experimental "ham" radio stations in Natal. Windy's receiving station was licensed in 1924 and the transmitting station on April 13, 1926. Windy's first callsign was A7Q later to become 3BE and then ZT5S.

Gustav Larsen (ZS5DN) : Gustav died on the 22nd of August 1947 and his station callsign, and equipment, passed to myself David Larsen. In 1952 I moved the ZS5DN Experimental Radio Station to Pinetown. The station was again moved in 1965 to the Transvaal and the callsign changed to ZS6DN. The Natal callsign ZS5DN was later held by my brother Roy Larsen.

Today the amateur radio station ZS6DN is located on a sixty hectare portion of the Farm Doornkloof between the cities of Pretoria, Centurion and Johannesburg in the province of Gauteng. The station is close to these large cities yet is "in the country" as the farm adjoins a game reserve. (Rhino, buck, Zebra and lots of birds on the two lakes - no lions or elephants).

David Larsen (ZS6DN): In 1952 my hobby was to became my profession when I joined Horace Dainty's (ZS5HT/ZS5C) electronics company SMD in Pinetown Natal. In 1963 Horace and I become founder members of RACAL-SMD in Pretoria. Horace Dainty was the Chief Executive Officer and I was the Chief Technical Officer of this new company. After Horace retired in 1972 I, in turn, became the Chief Executive Officer of Racal Electronics South Africa (RESA) and retired in 1978 when the controlling interest of the business was sold to the Grinaker Group. The late Ola Grinaker, like myself, was a South African of Norwegian descent.

Between 1978 and 1993, I upgraded the ZS6DN Experimental Radio Station and ran the co-located Salbu Research and Development Establishment (SRDE). After my retirement my sons James, Gernot and Mark ran the Salbu business operations.

Apart from looking after the livestock on the property the "farming" activities include maintaining the rhombic, yagi and the many other types of antenna systems situated on the property.

My late brother Roy (ZS6QU) became an active radio ham in 1952. Over the years Roy spent many hours on the ham bands using Morse code to talk to his friends around the world.

Marconi Day Award: On the Sunday following World Marconi Day it has become customary for the SARL's weekly Radio Programme "Amateur Radio Mirror International" to feature a different person who, in his own right, has made a major contribution to the development of Radio. I was very honoured to have been featured on the Sunday following Marconi Day 1996. My interest in wireless communications was initiated by dedicated amateur radio pioneers. My contribution was made possible by the dedicated support of the many radio amateurs and professionals who shared my fascination for wireless communications. For more about the dedicated amateur radio pioneers - CLICK HERE.


David Larsen (ZS6DN)

Racal Electronics South Africa
Racal Electronics (UK) & Racal Vodafone

In 1982 our associates, Racal Electronics (UK), established Racal Vodafone (later to become Vodafone plc). Vodafone in turn become a partner of Vodacom. 1993 Vodafone's international reach extends, with licenses and partnerships in Germany, South Africa, Fiji, Australia and Greece. December 1993 Vodafone connected its one-millionth customer.

All this because Racal adopted the South African RT14 and turned it into the  Squadcal (TRA906). See  TRA-906 - Modern Era SSB Sets.

In a 1992 CITY PROFILE interview with Jim Levi, Sir Ernest Harrison (Chairman of Racal UK) said "A South African offshoot gave him the tactical radio which was to make RACAL a byword of organic growth in the 1960's & 70's"- CLICK HERE

Racal-SMD and the Barlow Wadley Story - CLICK HERE

Amateur Radio and the SA Electronics Industry
SMD - Racal Electronics South Africa - Grintek - Saab Grintek

In 1952 David Larsen's (ZS5DN/ZS6DN) hobby was to became his profession when he joined Horace Dainty's (ZS5HT/ZS5C) electronics company SMD in Pinetown Natal. In 1963 Horace Dainty and David Larsen become founder members of RACAL-SMD in Pretoria. Circa 1972 RACAL-SMD became Racal Electronics South Africa (RESA) Ltd.

In September 1978 Racal Electronics South Africa (RESA) became Grinaker Electronics and was listed on the Johannesburg stock exchanged under the name GRINTEK.

GRINTEK became a front runner in the South African electronics industry and later became part of the Kunene Brothers Holdings (KBH) group of companies.

It was on the instigation of Zoli Kunene, in August 1995 that KBH acquired a controlling interest in Grintek Electronics Limited (GEL), a subsidiary of the listed company Grintek Ltd. In terms of the contract, Zoli Kunene, Keith Kunene and Graham Royston agreed to provide management and other services to GEL and were appointed to its board. In June 1998 Zoli Kunene was appointed Chairman of GEL.

Kunene Brothers Holdings (Proprietary) Limited (KBH) was incorporated on 21 July 1994 as an "active ownership" business with diversified interests. All five brothers have joined the full time employment of the company as active owners enabling KBH to provide a range of well defined services to group companies since its inception, KBH has rapidly grown its investment portfolio and today sits at the helm of one of South Africa's most successful Black business groups.

On 28 August 1994 Kunene Finance Company (KFC) was established for the purpose of raising medium to long term finance to fund the Group's investment program. KFC became 50,1% owned by KBH and 49,9% by six financial institutions.

Circa 2005 Saab AB of Sweden (SAAB) acquired the controlling interest in GRINTEK LTD. The company was delisted and became Saab Grintek Technologies.
Saab Grintek Technologies remains a leading empowerment technology group based in South Africa and recognised globally for its innovative high tech electronics, with a focus on ICT and energy management, logistics support and global connectivity services.
To download pdf file - CLICK HERE

Notice Published Apr 26, 2005: Saab AB of Sweden raised its interest to 70% from 21%, by acquiring a 49% stake in Grintek Ltd, a Centurion-based wholesaler and retailer of electronic parts, for 1.9 South African rands (2.237 Swedish kronor/$ 0.321 US) in cash per share, or a total value of 276.876 mil rands (326.033 mil kronor/ $ 46.795 mil US). The transaction passed regulatory approval.

World Distance Record on 144 MHz - February 1979

Transequatorial Propagation

George Vernardakis SV1AB describes how the first signals were heard via transequatorial propagation.

"First we heard the beacon on 144.160 MHz set up by Ray Cracknell ZE2JV in Southern Rhodesia (now Zimbabwe). The date was April 12th 1978 at 18.00 G.M.T. Ten months later I heard ZS6DN's automatic beacon with a colossal signal, but he was not at home! I went to 20 metres and put out a frantic CQ for any station in South Africa but got no reply. I returned to the cross-band frequency on 10 metres which we used regularly for 28/50 MHz QSOs and managed to contact a station in South Africa who was very far away from ZS6DN but who kindly offered to QSP a message by telephone. He was told that ZS6DN had gone out but would be back soon. I was terrified that the opening would not last long enough. But in a few minutes I heard ZS6DN calling me slowly on CW and we exchanged reports at 17.20 G.M.T on February 16th 1979. This was a new world record for the longest distance contact on 2 metres.

"Three days earlier, however, when I was not at home, Costas SV1DH had established the first TEP contact between Greece and South Africa when he contacted ZS6DN. As you know, my location is a mere 10 kilometres north of SV1DH's. I have a tape recording of my QSO with ZS6DN as well as with ZS6PW whose signals came through a few minutes later at 17.34 G.M.T. on that historic evening.(The local time in Athens was 7.34 p.m.). Of course the distance record was broken again on September 17th 1981 when I contacted ZS4BU who is 110 kilometres further south than ZS6DN".

Summary of first TEP contacts between Greece and South Africa: In South Africa, at the request of Dr Fred Anderson ZS6PW, Dave Larsen ZS6DN had set up a beacon which was first heard in Athens by SV1AB in February 1979. Within a few days ZS6DN had QSOs with SV1DH and SV1AB. The latter contact was a world distance record via the F-regions of the ionosphere because of the extra distance involved owing to the locations of the two Greek stations, as mentioned in the previous paragraph.For anyone who may be interested very comprehensive reports of the work done in transequatorial propagation during cycle 21 and earlier appeared in articles written by Ray Cracknell ZE2JV/G2AHU and Roland Whiting 5B4WR/G3UYO in the June/July/August 1980 issues of Radio Communication, the journal of the R.S.G.B. and in the November/December 1980 issues of QST.

For further details :- Amateur Radio - World Record (Africa/Greece) and The Dawn of Amateur Radio: A Personal View by Norman F. Joly.

Ham Radio - Callsign LookUp and Links

Buckmaster's World Wide HamCall(tm) Server
QRZ - HamCall Server
U.S. Amateur Radio Callsign Lookup Page  (FCC - Data Base)
U.S. Amateur Radio Callsign Lookup Page  (FCC - Licence Search)
U.S. Amateur Radio Callsign Lookup Page
NCDXF/IARU International Beacon Network
The South African Radio League
All About Ham Radio - Amateur Radio FAQ and many other links

Twelve pictures follow after this text - the images are loading now, please wait.
A cluster of Stacked 2x5 elm 6 meter Yagi Arrays These arrays are used in conjunction with the Meteor Burst Communications Master Station housed in the green shelter that can be seen in the lower centre of this image
South African Transequatorial Propagation Team February 1979: L/R - Fred Anderson ZS6PW (Team Leader), John McCoy ZS6JM, Doug Hutchenson ZR6JH, Dave Larsen ZS6DN - Antenna: 144 MHz KLM Stack Array - 4x 16 Elm yagi array
Dick Kessler (K2SZE) - David Larsen (ZS6DN) and the GRC100 Transceiver
Julian Bouttell (ZS6AOU) and James Larsen in the Salbu Laboratory
A view of the Salbu Laboratory
Julian Bouttell (ZS6AOU) and James Larsen
Roy Larsen ZS6QU - February 1991- "a dedicated CW operator"
Roy Larsen ZS6QU, Karl Larsen (cousin), Dave Larsen ZS6DN
Dave (ZS6DN), Ursula, Empty (ZS6KD) and Audry
Photograph taken at Empty's home June 1998
W2ONV - Our friend Bill's Radio Room
10 metre, 6 metre and 2.7 metre diameter Parabolic Reflectors
The ZS6DN BEACONS are in an "air-conditioned and pressurised" shipping container under an IBR roof.
This is the location of the ZS6DN component of the NCDXF/IARU International Beacon Network
Gus Larsen ZS5DN - 1930's
Sivert "Wireless Windy" Larsen ZS5BE - 1930's
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