Warkworth Satellite Earth Station. Dish antennas (L-R): WRW-02, WRW-01, WW3 (Aussat)
By Ralph Sanson*
1964
Intelsat was set up as the body for international communications satellite operations. There were 77 member countries.
1965
New Zealand joined Intelsat and started planning for an NZ Satellite Earth Station.
1968
Site surveys were made for a location in the upper North Island. The selected site was south of Warkworth.
Intelsat had test flown three Early Bird type satellites in geostationary (synchronous) orbit, however provision was made for future satellites in lower orbits to obtain less delay. This would require fast-tracking capability and up to five antennas for handover to the next in-view satellite. The Warkworth land could accommodate this and, being in a natural valley, was largely shielded from interference from ship radar, HV power lines and industrial facilities.
Warkworth Satellite Earth Station under construction
Building the first antenna at Warkworth Satellite Earth Station
The initial transmitter amplifiers were four 3kW Klystrons (catering for telephony, standby, TV and TV sound). Later two 3kW Travelling Wave Tube Amplifiers were added. These valves cost $110,000 each. Receiver system was via Low-Noise Amplifier, a unit cryogenically cooled to near zero with refrigerant and Stirling pump heat exchanger, the coldest parts sealed in a vacuum container.
The bespoke microwave tower and communications building (top right of the top photo) were designed by the Ministry of Works.
11kV electricity was supplied via underground cable and an underground switchgear/415V transformer room. Two V12 Mitsubishi Diesel generators supplied backup power.
1971
The station opened, with staff comprising 16 radio technicians, 3 transmission technicians, Handyman, Custodian, Recorder. Shiftwork: 3 on shift 8am-4pm, 2 radio 1 Mux on 4-mid, 2 radio on mid-8 shift.
Original staff and some of the build team
Back: Alan Dewar, Brian Fanning, Jim Shearer, Peter Mcnab, Kevin Mulholland?, Ben Oldenburgh, ?, ?.
3rd row: John Morgan, Dave Thew, Mike Buchanan, Brian Flynn, ?, ?, John Diamond (engineer).
2nd row: B (Tinny) Hogan (Chief tech), Neil Watts, Correlene, Keith Surridge, Graeme Pullar.
1st row: Dave Chittenden, Kevin McGurk, Warrick Hearn, Mike Pellow, Joe Crandle.
3 crouching at right: Probably from NEC or NZPO.
Staff not identified yet: Don Mckellow, C Castelton, W Warwick.
NZPO built extra staff accommodation in Warkworth. Eleven houses and four flats in total were available.
Neil Watts at the WRW-01 console. This appears to be an early photo, as the 8 or 12-channel HP rackmount chart recorder is at the end of the console whereas in all the later photos it is part of the row of racks behind the operating console (see next photo).
Original control room, Warkworth Satellite Earth Station
Initially traffic was via an Intelsat III satellite but transferred to a higher capacity Intelsat IV type within 6 months.
LNA receiver exterior and interior
In addition to the NZPO telephone circuits, the station had television capability. For the first time, NZ could play or transmit events live rather than, for instance, using a Canberra bomber to deliver film of the first moon landing to get TV footage to NZ homes.
Because countries used different TV colour and scanning systems, a converter made by Rank Cintel UK, one of few in the world, was installed and used including for local TV companies to convert programmes and advertisements. This was achieved using the microwave links to and from Airedale Street in Auckland, via an intermediate repeater station at Moirs Hill.
TV standards converter
TV operated on completely separate equipment for the video and audio channels. Later, Intelsat adopted a combined system with audio and video together and squeezed two channels of TV onto one satellite transponder, much more cost-effective although there was some degradation of quality.
The dominant aerials in this photos are WRW-01 and WW3. Just in front of the microwave tower there is a 4.5m transportable setup, which was used for TVRO for a while and was also one of the transportables sent for site testing at Scott Base (Antarctica). Also parked at the building is the COW (Cellular On Wheels) trailer package which was stationed here between jobs for testing and maintenance. Notable events covered with the COW included an Ironman marathon in the central North Island. It was also used to provide cellular phones on Great Barrier Island during Christmas, prior to a permanent cellular service being installed there.
The building was designed to showcase the technology, and tour buses added it as a half-hour stop. Visitors could go upstairs and view the equipment room from balcony windows and continue up to the rooftop gallery with sightline to the antenna.
1984
Second antenna at Warkworth Satellite Earth Station
Although still full-motion, this version was not equipped with fast slew rate motors which would be required for tracking low-orbit satellites. Equipped with three NEC 3kW TWTA (one is pictured at right), it was later refitted with three 350W Maxtech SSPA (Solid State Power Amplifier) transmitter equipment.
Valve amplifiers, especially travelling wave type, to carry 2 or more carriers, need each carrier to be backed off by around 10 dB. for WRW-02 the TV was put on a separate TWTA and combined with the telephony carriers at waveguide level. The telephony traffic had one primary and one switchable backup TWTA.
Solid state being more linear, work OK within 2 dB backoff so everything could go on the one path. By this time WRW-02 had the second polarization, so there was one SSPA for each polarization, with switching to one standby should either fail.
A single FM TV carrier would be around 50 W to 100 W to the antenna, most FM telephony multiplex carriers 5 or 10 Watts.
The power supply was rearranged with two new Detroit V16 generators installed in the new site and two new Dorman IL8 generators for the main building, around 500kW each. Staffing had increased to around 24 technical staff.
The main building was extended north to accommodate new equipment repair room, library and conference room, new control room, mainframe computer, printer rooms and senior technicians’ office.
A separate public relations building removed the need to cater for visitors in the main complex. Specific tours for technical interest groups could still be booked and fulfilled by the technicians.
Building the HPA room for WRW-02. NEC employee in the foreground, Warwick Hearn in background.
Left: NC Watts doing the LNA thing. Right: Don Scott in the HPA room of WRW-02.
Ralph Sanson in the new control room
Jim Shearer at the control console
Also, two receivers for maritime VHF were installed there, cabled back to Auckland Radio ZLD.
1988
WW3 dish antenna (visible in top photo) on the higher frequency Ku band to connect with the Aussat 3 satellite, providing television and telephony to/from Australia. This used mostly USA equipment: a 9.2m RSI antenna, 700 Watt Varian Travelling Wave Tube Amplifiers, LNR Low-Noise Amplifiers and a passive-cooled shelter building of the type used in the Australian outback.
1990 – 2020
Satellite antenna at Chatham Islands
1991
Radome antenna at Arrival Heights, Antarctica. Photo: TCNZ-ONLINE, July 1992
9.1m radome-protected antenna installed at Arrival Heights, Antarctica for a satellite link to Scott Base. This was to provide satellite backhaul to Warkworth and the circuits were carried on a 512kb/s digital link. Rather than house the traffic equipment at site, the C-band RF signals were processed at Scott Base and conveyed via fibre optic cable, then converted direct to RF into amplifiers. This enabled changes to the configuration to be done at base without visiting the site. SCB was linked to Christchurch Exchange and payphones installed at the Base.
18m satellite dish at Wellington
18m Mitsubishi wheel-and-track antennas installed at Wellington (WEL-01A) and Rangiora (RAN-01A) with 3kW Varian Klystrons amplifiers. These provided TV links between Auckland, Wellington and Christchurch as well as an 8.448 Mb/s digital link for telephony/data. Rangiora later was equipped with another, smaller, dish (RAN-02B).
Satellite dishes at Rangiora
Radio Depot staff performed the local work, Warkworth staff made several road trips to reconfigure for other projects. Eventually the sites were closed and scrapped.
These two sites were remote-controllable from Warkworth (the only full-time manned site) using the DEC PDP11/44 mainframe computer monitoring and control system installed in 1984. At times, antenna tracking would be lost or transmitters would fail, these problems would be remote switched to standby equipment until the fault could be repaired.
2000s
With reduction of traffic due to new fibre route uptake, Warkworth was using just one dish. This didn’t last long with satellite failures and requirements to pointover to other types which required different polarisation schemes. Scott Base was a difficult destination as not all satellites can see that location, Warkworth must uplink to the particular satellite available.
The Intelsat rules for 24/7 staffing had been relaxed and shiftwork was reduced in stages until being phased out as equipment reliability and backup routes progressed. Around this era, Telecom had been formed and sold and split into the various entities: TNI, TNO, Auckland ROC. By the end, the satellite group had been shuffled amongst these about 8 times.
Alarm and callout supervision were moved to the Hamilton centre and management moved to within those groups. Many staff left for positions with other operators. Virtually all of Telecom’s radio, telephone and data technician jobs had been contracted to “service companies”, the radio depots closed. Maritime and VHF radio services also exited.
Various proposals were looked at for outsourcing the Warkworth site. Finally, in 2004, BCL (formerly NZBC) contracted to run the technical operations, acquiring the remaining three staff supplemented with their Auckland-based staff and rigging team for the antenna tasks (“outside plant” in NZPO terms).
2006
9m General Dynamics Satcom Vertex RSI antenna using the 350W Maxtech SSPA’s (recovered from previous use in WRW-02A).
SKY TV leased the WW3 antenna and fitted TV uplinks for their services carried on the Optus (Aussat) satellite. Two 4.5m receive dishes were added for downlink of overseas programmes to be rebroadcast.
2008
Two 16.4m Vertex RSI antennas replaced the original WRW-01 antenna. These were equipped with Vertex RSI 200W SSCA (Solid State Convertor Amplifier) transmit equipment.
As soon as the 16.4m WRW-08 (right) entered service, the original WRW-01 (left) was dismantled to make room for the second 16.4m dish, WRW-09.
Later the WRW-02 NEC antenna was withdrawn from service and leased to Auckland University of Technology (AUT) for Radio Astronomy. They had earlier leased a hilltop site and installed a Patriot antenna as NZ pathfinder project, part of a bid for the SKA (Square Kilometre Array) project.
2010
WRW-11, a 7.3m Vertex RSI with 100W Vertex RSI SSCA, was installed for the Scott Base service when it changed to a different satellite.
Antennas at Warkworth, L-R: WRW-09 (16.4m) in front of the old WRW-01 base, WRW-14 (3.6m) for odd jobs, WRW-11 (7.3m) installed in 2010, WRW-08 (16.4m) the first of these antennas, built in 2008.
2017 and beyond
The microwave tower being removed
The microwave tower, no longer needed since the station traffic was now backhauled on fibre, was removed to give the Inmarsat Ka band antenna a clear view.
From 2024 the use of the AUT equipment and sites transferred to SpaceOps to augment their original and growing operations located at the former Awarua Radio site near Invercargill.
The Earth Station site has merged to become a teleport facility, with multiple operators establishing their linking services away from urban land constraints and the spectrum conflicts resulting from C-band take-up by cellular services.
* Ralph Sanson transferred to the Warkworth satellite earth station in 1981 as radio technician staff. At the time of writing this article (2024) he was still at the station, looking after the RF operations on a part-time basis.
“I’m pleased that my initial posting at Makara Radio (1973), RTC qualification and later moves to New Plymouth Radio Depot and Rotorua Radio Depot got me good training and technology experience.”
