During 1997 the VK6WIA were asked if they could install and host an International HF beacon, built by NCDXF (Northern Californian DX Foundation). A clever project that linked several HF beacons around the World via GPS timing, so all beacons identified in exact sequence, starting with the 20M band, all HF beacons identifying one after another and then onto the next HF band . The HF beacon was installed at the Roleystone site and turned on at... 1pm on Sunday the 18th of May 1997. Frequencies... 14.100 18.110 21.150 24.930 28.200 The callsign VK6RBP had to be a "R" call and the BP was to indicate Beacon Perth. The beacon antenna is located well away from the main tower and hut. This was considered essential to keep the HF RF out of the equipment in the shacks at the site. Some 50 metres of large diametre LDF550 was buried between the shack and the beacon antenna. The loss on HF using the LDF550 is close to zero on all bands. The LDF550 before burying Cliff VK6LZ & Rob VK6LD
digging in the LDF550 coax
Will VK6UU digging in the coax. VK6RBP LDF550 coax in trench |
The Cushcraft R7000 was used at VK6RBP.
This
antenna works on...... 10m, 12m, 15m, 17m, 20m, 30m, & 40 metres.... 40 metres is not required hence it was not attached as shown in the photograph above. This was advised by NCDXF. The HF verticals used for VK6RBP have not proved reliable. VK6RBP is now on its 3rd antenna, with various corrosion problems inside the traps. One of the RF traps showing an open circuit due to corrosion. VK6RBP
antenna with main 80m tower at roleystone.
The antenna is guyed using non conductive guy cable. One of the antennas was damaged a few years ago when the Roleystone site was being cleared of scrub, with the contractor's equipment tangling with one of the antenna guy cables and pulling the antenna down. Antenna pulled down and damaged Mal VK6LC donated the non conductive antenna guy cable...Note earlier different antenna...Mal VK6LC shown in photograph. The current intermittent problem with the R7000's antenna on VK6RBP is most likely the center trap, as the 21 MHz SWR goes from good to bad. All other bands are okay. The problem has been present for several years now and needs attention. |