"G'Day from IRLP Node Sydney Australia"
Those were the first words that our HAM friends around the globe heard when the Sydney IRLP node came online. This has been a project initiated by Peter VK2YX some 8 months ago and can only be described as a baptism of fire when combining Linux, radio and patience.
Almost 8 Years ago, a ham from the Sydney Northern Beaches initiated the first internet linked conversations by using some simple techniques, rubber band and good old Armstrong. What a fantastic approach and initiative.
Since then we've had Steve VK2BGL and Peter VK2YX use I-Phone to link the VK2RBM repeater around the world. This type of linking initially enjoyed great success but soon we were to discover a number of serious flaws in the linking mechanism. Peter VK2YX instigated a number of enhancements that included DTMF control but this too was to fall victim to the instability of the windows operating system.
IRLP was developed to be a stable remote solution, a system that could be placed into the remote areas of the world and run without human intervention. David Cameron VE7LTD put together the IRLP solution, putting the Speakfreely package onto the Linux operating system. Dave has done a great amount of work making the system as user friendly as possible yet providing some nice features not seen in any other system. To ensure only licensed repeaters join the network, the repeater has to be validated using public key encryption, this ensures there is little or no chance you can ever compromise the system.
There are a number of very capable hams that provided direct help and also inspiration in putting this whole system together. To my friend Geoff VK2XJG for his Linux support, Pete VK2JPJ for his bandwidth and ability to not throttle me when I threw a wobbly and Dave VK2JDC for his support when I just wanted to walk away and forget about the whole thing..
The IRLP System
IRLP Radio FM828 modified with CTCSS receive IRLP PC P133 with 64Mb, Redhat 6.1 Router P2/300 256Mb with 74Gb storage Internet 128K ISDN Network 100Mb switched Enjoy...Pete VK2YX
Click here for more information on our IRLP system from Peter.
The BMARC 70cm repeater on 438.375Mhz is now operational from the Lawson repeater site. Power is 25 watts and uses the same antenna as the 2Mx repeater on 147.050Mhz. Initial reports are very encouraging and the word is out that it has the best 70cm repeater coverage in the Sydney area.
VK2RBM
The photos show most of the 2m repeater at VK2RBM. The only bits not shown are the battery
and of course, the antenna. The battery consists of six large (500A.h) lead-acid cells and
is situated in another part of the building.
All the rest of the repeater is arranged along the top shelf and consists of (L to R): 50Watt power amp, 13.8V power supply (this also charges the battery), the repeater unit itself and the computer running the controller program. The diplexer, consisting of 6 cavities with phasing harness, can be seen behind the repeater unit.
It is worth noting that the computer (as modified by Adrian VK2BFN) and its monitor (donated by Dave VK2IH), as well as the repeater itself, all run from 12 volts and so the whole system will run uninterrupted from the battery in the event of a mains failure.
The other radio-looking equipment in the photo on the right is bushfire brigade gear consisting of low-band VHF, high-band VHF and UHF units. The large rack-mounted unit behind Alex’s head is a power supply for the brigade equipment, nothing to do with us, but nonetheless built by an Amateur, Noel VK2JG.
In
October 1998 we doubled the height of the dual band repeater antenna system. The photo at
left is the original antenna system fed with RG213U. With the new installation the feeder
cable is Heliax to accommodate the 70cm repeater in the future.
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Unfortunately, the whole shebang fell down 2 weeks later during a major
windstorm with gusts up to 150Kph.
So, in the meantime we are back to our original antenna while planning a bigger
better and stronger system...
Six months later...
Well here we are again on 22nd January 1999. This time we have erected a 50ft Hills comercial mast using 5 sets of guys. We repositioned the mount at the very centre of the roof for maximum stability.
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