VK3RSP

VK3RSP has sweeping views of the Mornington Penisula & Melbourne’s suburbs. It services amateur operators in and around the Southern Metropolitan Districts.

The SPARC 2m repeater, VK3RSP, is located at Arthurs Seat on the Mornington Peninsula.

VK3RSP

VK3RSP is on 146.675 MHz with a -600 kHz offset. You’ll need an 88.5 Hz CTCSS tone to open the repeater.

IRLP Node

The SPARC IRLP node is 6330 and it’s connected to VK3RSP.

Echolink

The SPARC Echolink node, number 290314, allows access for registered Echolink users to communicate via VK3RSP-R anywhere in the world where internet access is available.

The early days of our repeater by Alan Robinson, now a silent key.

Early in 2000, SPARC finally decided to investigate and if feasible, install a repeater. Somehow I landed the job of manager and coordinator.

Firstly the site. I was hoping for the Dept. of Civil Aviation installation at Arthurs Seat, (this had previously been done at Mt. William, Mt. Barrow, and Mt. Mittamatite, (Corryong) however, tests showed that this was not possible due to interference from other users in the area, particularly from the Telstra paging system. The next choice was from a site managed by Brian Baker, VK3HB in the grounds of the Red Hill Consolidated School. This was eventually ruled out due to coverage problems.

Prior to this going on, Mr Jim Houlihan, Project Engineer from the Shire Office had approached the Club to ask for assistance and /or consultancy in developing further the TV installation adjacent to the Rosebud Shire Office. Brian volunteered on behalf of the Club.

One Thursday morning when we were discussing possible sites, Jim came into the club rooms, listened for a while and then offered what is now our VK3RSP site, free of charge, with power and unlimited access until further notice.
The site is in the maintenance workshop of the Mt. Martha Public golf course and was previously used as a communication site for contacting the green-keeping staff on the course. They had no further use for it.

Jim produced a topographical survey map of the area, and from this, we knew that with the top of Mt. Martha being in direct line of sight between the mast and Rosebud, we would have a shadow to that area; we were approx. 20 meters too low, but with the facilities we were given, we would have been very foolish not to accept. We applied for a licence and the call sign VK3RSP, although the man could not really see why we wanted that call sign, we received a licence!

The Shire aerial was mounted on top of a tubular guyed mast, approx. 16 meters above the centre of the large maintenance workshop, the aerial was fed with heliax cable (FHJ4/50 or similar) This came from the office of Mr Damien Willis, the head greenkeeper who had his staff re-route the cable out of the office wall, across the driveway catenary, over the roof and through a hole punched into the wall of the workshop, where we intended to put our installation.

Unfortunately in their haste, they pulled the cable too hard and we lost a $100 connector in the cavity of the office. We now had a surplus of cable in the workshop and no connector. No problems – Brian cut the surplus off and terminated a new connector –  a tedious job. David Swallow, VK3AMX, produced two Philips 828 transceivers, (one as a spare unit) Brian a power supply, an ex-work colleague of mine a handbook and we were set to go.

The transceivers were modified in accordance with the Philips circuit, two circuit boards for the ident and tail were purchased from Peter Cossins at Wantirna South, and mounted within the units. Crystals were ordered from Mr. Morrison at Moorabbin. Brian manufactured a lockable cabinet and installed it in the corner of the workshop. As we had one run of cable to the mast I intended to use the one aerial for both transmit and receive.

The five cavities required for the diplexer were acquired, the tuning range was outside the frequency range we required so my very good neighbour Mr. Peter Pilipsen modified each cavity by shortening them by 5 cm. The filters were band-pass type, these I modified by adding a tuneable capacitor in series with one of the loops to make them a slot type. Mr. Neville Sleep from Polar Electronics supplied the high grade capacitors and advice, but the capacitors were very difficult to mount within the cavity and still allow them to be tuned.

Ray Miller VK3RF produced the required suitable capacitors. The diplexer I made using RG8 co-axial cable. On the receive path are 16 connectors and 3 T pieces, transmit 12 and 2. Fortunately I had collected these over a period of time. On the receive path I achieved in excess of 100db rejection from the transmit frequency, with a figure of 70 db plus on the transmit path. A frame was made to hold the cavities.

The repeater was now complete, it was put together and operated from my location for a couple of weeks, later being moved to the clubrooms where it operated for approx. three months. The hold up was that the cherry-picker being supplied by the Shire was a little late in coming.

Henry Biggelaar VK3DOS suggested that we put a temporary aerial at low height on the mast. With the help of the greenkeepers, he was able to mount a folded dipole approx. 6 meters above the roof, an RG8 co-ax was run back to the repeater which had been installed in its permanent position.

The day arrived, we had the use of a cherry picker. Blayne VK3FIS volunteered (or did he) to go up in the air. He removed the redundant Shire aerial, installed our folded dipole a quarter-wave from the mast to achieve approx 3 dB gain, and using the low loss coax. as a feed. Blayne used the low-level aerial for his packet.

Blayne also took a series of photos around the 360 degrees of the mast to form a panoramic view, this confirmed what we know today, there is a deep shadow over Rosebud/McCrae. Unfortunately, the aerial collected water which could not drain out. Within the month the water level in the aerial rose to reach the 92 ohm matching section and the aerial became unusable. Back to the low-level aerial! Sorry, Blayne!

Another aerial was produced, Paul VK3DPW obliged with the cherrypicker, (at his expense), and we were back in business. Paul estimates that at least a litre of water was drained from the aerial when it was turned over. I have since repaired this aerial.

Some time after this, when I was In Queensland, Neil VK3TNB (now VK3YS) and Owen VK3BC installed a 6 db vertical at the very top of the mast, with a run of co-ax RG213 back to the repeater. This aerial was used for the receive path with the low loss cable and the RG213 cable for the transmitter.

By this time the original transceivers were past their prime and were replaced with a Philips Tx814 transmitter and a receiver Rx814, courtesy of Neil and Owen. I decided to install another aerial on the transmit path. A matching harness of RG11 was made using ¾ wave sections between the feed points, this was installed between the two aerials, spacing between the booms was .8 wavelength. (Polar Electronics advice). We now had approx. 6 to 8 db gain. on the transmit side. This more than made up for the difference in loss between the two cables.

Neil was the member in the bucket on this occasion, you could see the bucket shaking from the ground. Health problems have caught up with me, and the younger generation has taken over, however, I know the repeater is in good hands. PS. Brian and the Club received excellent remuneration for our consultancy from the Shire.

Thank you to Alan Robinson, now a silent key for this substantial background history.

VK3RSP Mt Martha Nov 15 2018. View north to Mornington.