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
5th April 2020