Amateur Radio in the South East of South Australia and Far West Victoria
I’ve used the old Naracoorte Mk1 controller and installed it on a face plate to be used for VK5ROH. It will make it easier to see what is going on in future. One day Peter and I will install it at The Bluff. It may require some re-wiring of the plug but at least it will be ready for the IRLP/Echolink when we get our WIFI connection from the clubrooms.
John
Peter VK5BE, Andrew VK5VKC, Colin VK5DK and Leith VK5FLAR installed the UHF repeater (439.825/434.825) at The Bluff on Sunday 24/5/20. The unit is now running off mains power.
The antennas are temporarily placed at this time until tower issues are resolved. In the meantime there are much improved signals, especially to the NW. Well done fellas. There was quite a lot of activity testing the repeater this afternoon. Not as good in Mt Gambier as expected – it’s a long way away, but still usable mobile. David VK5HDW had usable signals mobile in Millicent.
The LVD for the Mt Eckersley repeater is now finished and working ready for installation in the VK3RSW cabinet.
The device makes use of a solid state relay. A microprocessor looks after the management of voltages. If the battery voltage falls below 11.9 volts the relay turns off and does not turn on again until the battery voltage exceeds 12.7V (80% charge) for 100 minutes. The timer ensures the battery is in good condition before the repeater is used.
The normal on range is from 13.8V (fully charged) to 11.9V (20% charge).
The device was home brewed and software program written in the VK5DJ shack.
On Sunday, May 17th, a team comprising of Peter VK5BE, Colin VK5DK, Andrew VK5VKC, and Andrew VK5MAS fully dismantled the 70cm repeater from the Crouch Street North water tower site in Mount Gambier.
This included the repeater and link equipment rack, all coax feeders and power cables, antennas, and solar panels.
As a result, the VK5ROH repeater will be off the air until further notice, for hopefully only a week or so.
The 70cm repeater will now be re-built using mains power in lieu of solar power, plus will no longer be linked to the 2m repeater VK5RSE at Mount Graham, once it is re-installed in our new facility at The Bluff.
Improved IRLP and Echo-Link facilities will also be added later.
Initially we’ll retain the off air feed from the clubrooms but a wifi link is highly likely. WiFi will be a significant upgrade by allowing us to put the IRLP/Echolink node at The Bluff. We await some work to be done at the Gambier Electronics site.
VK5RSE at Mount Graham still remains on air as a stand alone 2m repeater.
Report by Peter VK5BE on behalf of the repeater committee
We have received notification from ACMA that our frequencies for the new Mt Eckersley repeater will be 146.875 MHz TX (user receive) and 146.275 MHz RX (user TX).
The link frequency will be 449.875 MHz but users won’t need to worry about that.
John VK5DJ
Repeater coordinator
The Naracoorte fence has been removed, not only does this tidy up the site but it also means that the Council people who tidy the whole site can also mow closer to the the repeater site – with the exception around the tower. I guess we’ll look to the NARC to poison regularly.
This will be great for the repeater maintenance team as they will no longer have to wear pith helmets when entering the area.
Thanks to Brian VK5VI for arranging the cabinet and President Peter for getting it from the VK5RHO site.
The solar charger will be mounted at the top on the non removable back of the cabinet. Below this will be the repeater for Mt Eckersley which will be on 19″ mounting holes. The cabinet is quite wide so the right hand side of the 19″ mount is on a bar that is fastened from top to the horizontal bar. This leaves about 200mm gap at the right for limited access.
Peter plans to cut an access port in the rear of the cabinet behind the repeater. Normally this will have a covering plate attached by bolts with captive nuts. The cover will maintain the vermin proofing. Rear access to plugs, antenna connections etc is necessary as Tait equipment is quite heavy and difficult to remove from the cabinet if only one person is present.
In the lower section will be placed the 4-6 cavities (until we have tested we won’t know how many we’ll need) and the battery.
We are still waiting on the allocation of frequencies although the callsign VK3RSW has been confirmed.
The repeater controller at The Bluff (Mt Gambier end) only has capacity for one repeater and two RF linking ports. The links were occupied (one to Mt Benson [Kingston ] and the other to Naracoorte) a solution was needed to supply a third RF link to Mt Eckersley.
The simplest solution was to take one link (that to Mt Benson) and split it into two with one going on to Mt Benson and the other to Mt Eckersley.
This required a new sub-controller to be designed and built.
The sub-controller would have most of the facilities of the main controller but control would be completely separate from the main via DTMF tones with a separate code access.
The sub-controller was designed and after much checking and consultation boards were ordered and supplied. One board has been populated with components and John 5DJ has preliminary software working. This is most encouraging as PCB design is always fraught with mistakes but fortunately so far all seems to be satisfactory.
Brian 5VI has been occupied building the hardware component of the project.
Fortunately we have a spare almost completed RF subrack on hand and all that is required is some additional wiring. This will be the main component housed at The Bluff end of the link. It will have the two RF links (to Mt Benson and Mt Eckersley) and the sub-controller module. Both RF links will be Tait T85x Series II (synthesised) modules).
For the Mt Eckersley site the RF equipment will be housed in one 19″ subrack and will contain the RF link (to The Bluff), the local repeater, and the repeater controller. All radio gear is modular and should a fault occur a replacement module can easily be fitted and the faulty module returned for repair. This will almost always eliminate the need to carry test gear to site.
To reduce site power consumption all RF equipment will be of the Tait crystal-locked variety although provision will be made to replace with synthesised equipment in emergency cases.
Current status is the Mt Eckersley radio subrack is being manufactured, is work-in-progress.
We have sourced a vermin-proof lockable cabinet which will house all radio, duplexer cavities, and battery-charging equipment and which will be available once travel restrictions are lifted.
Brian and John
VK5VI/VK5DJ
5th April 2020
On Friday evening of March 3rd 2020, amid the COVID-19 pandemic where all gatherings and meetings are banned, SERG held its first ever meeting over its 2m repeater network.
Chaired by the President, Peter VK5BE, and assisted by Secretary Col, VK5HCF, a total 24 stations participated, plus 1 apology.
As the first Friday of each month is normally an “Activity Meeting”, the meeting commenced with an episode from the ARRL podcast “The Doctor is In”, chatting about various antennas, following by the latest VK6 News Broadcast, which discussed numerous topics.
This was followed by all those present having an opportunity to comment about the meeting and forward suggestions about future meetings. It was agreed by all that this format should become a regular feature of our Clubs activities and now look forward to different ways of presenting activities via the repeater network.
Peter VK5BE
Added note from VK5DJ
David VK5HDW made a suggestion we should have a get together each Friday night that is not an activity night or business meeting.
Next Friday 10/4/20 at 7:30PM there will be a quiz night. A mixture of general knowledge and ham questions. Have a pen and paper handy to write your answers. We’ll mark our own at the end of the quiz.
First prize a roll of toilet paper to be awarded at the first face to face meeting after the crisis. You’ll have to hold on till then.
Tom, VK5NFT has been busy on his day off. His trusty whipper snipper has cleaned up the yard. A poison follow up will happen soon from those with a supply of suitable poison.
The webmaster is told that no hippopotamuses or giraffes were found in the long grass, not that they would have survived Tom and his whipper snipper.
Our new VK5RMG home can be seen on the right.
