Roleystone Technical Layout


This page is in relation to the overall technical layout of the site and not circuits. For example the location of equipment and general running of the site so anyone making a visit to Roleystone has some basic knowledge of what is there and where it is. Also a basic understanding of how various pieces of equipment work and interface with other pieces of equipment for example the WIA news link system.


Roleystone is a mains powered site that has two main regulated 12 volt 30 amp supplies that are wired, via isolation diodes,  in parallel. These power supplies float a large 500 AH battery. All the equipment is 12 volt and as such is wired across the power supplies - battery.

If the power fails then the equipment continues to operate as is. There is no switching of the equipment to the 12 volt battery system as said the power supplies and battery are all in parallel.

At the back of the centre rack is a soft start 240 volt distribution. This was added, as after a mains failure, the switch on surge often "blew" the resettable mains circuit breaker in the hut. The mains failure often occurred when no one was on site and when the power was restored the circuit breaker would trip. There are two outputs from this soft start unit, and one of the outputs is not working.

Mains Power Failure

If the 240 volt mains fails, an audio message "mains failure" is placed on the 2 metre repeater VK6RAP only. The message is on the tail of the repeater and at a low audio level so as not to be too annoying.

If the mains is not restored, after 12 or more hours, depending on usage and the state of the backup batteries, a low voltage tone will be heard on the tail, which indicates the battery voltage has dropped to 11.75 volts. Once the battery voltage drops below 11.5 volts the low voltage cut out operates and disconnects the 12 volt batteries from the equipment. This protects the batteries from deep cycle discharge and hence long term damage to the batteries.

The D-Star equipment on site runs on a separate 12 volt power supply and back up battery and has no alarm indication or low voltage cut out.

Equipment Layout

There are 3 racks at Roleystone.

The left hand rack contains....

  • The 2 metre repeater VK6RAP
  • A 2 metre pre-amp and 146.100 Mhz crystal filter
  • The 70 cm repeater VK6RAP
  • The 70 cm repeater's duplexer
  • VK6 WIA news control
  • 146.3 MHz WIA news link transceiver
  • 12 volt distribution

The centre rack contains....
  • The two 12 volt 30 amp power supplies
  • Technical DTMF decoder
  • 2 metre engineering receiver for site control (rarely used)
  • 12 volt distribution
  • International HF beacon VK6RBP

The right hand rack contains....
  • D Star equipment