Month: July 2024

Working bee at new site

Dish down, weeds gone, inside cleaned and organised
28/7/24 – Bluff Working Bee #1 at the Lime FM site in preparation for the big move
 
 
Attended by :-
Col    VK5HCF
Norbert VK5MQ
Jack VK5EBA
Tom VK5NFT
Peter VK5BE
 
Tasks completed
Excessive vegetation removed from within the Lime FM compound ready for spraying when weather permits.
New hut tidied up, swept and rubbish removed.
Obsolete cabling removed from inside hut.
Satellite dish near diesel generator removed from pole.
 
Planning now underway to fabricate the mounting frame for the solar panels ready for Nick to weld up as soon as he returns.
 
Stages
1) Gain permission for use of tower and site (achieved)
2) Clean up of building and surrounds, remove dish (achieved)
3) Construct solar panel frame and install on old dish mount. Four solar panels @ 250W with batteries and charger to completely power equipment using solar.
4) Move all equipment to new building. Power up VK5RMG 2M.
5) Lower link antennas and mount on main tower.
6) re-establish full operation with links active.
 
Cheers,
 
Peter VK5BE
 
 

VK5RMG update July 2024

Following a number of visits over several weeks the repeater team have now found a workaround that prevents the trunking radio interference from taking over the system.

Maxwell has put a huge amount of effort into the problem over this time and he now has an excellent understanding of how the Philips PRF1520 operates. It should be said that this is a very complex radio as it can be used in many ways. There are dozens of configuration jumpers and they need to be just right for our particular usage.

The main change is to use the PRF1520’s internal CTCSS hardware at 91.5Hz.

In the past when VK5RPM was transmitting and mixing with two or three other transmitters the receiver would open and we would hear the interference. This was because the 91.5 decoder was inside the controller and audio (the nasties) were fed into the audio system even though the controller was not responding to the mute.

We have now activated the CTCSS detect in the PRF15 which means that if there is no 91.5 Hz tone, not only  is the mute not activated, but the audio is also inhibited.

The repeater operation is now less susceptible to the interference. It will not show up at all if communication is coming via our links but if the incoming user’s signal on 146.3 is weak, you will hear white noise in the background or may even cause the weak signal to drop out.

This is not a cure for the interference, it just means we will not be bothered by it and we’ll have some peace!

The cause of the interference is still being investigated.