Sorry for the lack of posts over the last few months.
On the 29th January 2015, Tony VK5RF and Michael VK5ZEA drove to Whyalla (540 km round trip) to collect three duplexers from the QTH of Arne VK5NEX. In the previous week, Matt VK5ZM had transported them from Paul VK5BX in Adelaide (390km). Quite a journey!
One duplexer was destined for the VK5RAC 70cm FM repeater at Pillaworta Hill. This was built from a flat-pack notch duplexer and a pair of bandpass cavities. The notch duplexer was the one previously used at the VK5REX D-Star repeater. This was to replace a HUGE six cavity duplexer that was too big to fit in the rack. The new duplexer fits nicely in the 19" rack, sitting just above the 70cm repeater equipment.
The other two duplexers were for the VK5REX D-Star repeater and these were installed on the 31st January 2015. A new 70cm duplexer to replace the temporary unit provided by Paul VK5BX. This new duplexer uses my original 1MHz wide six-pole DCI filter, a notch cavity filter and a pair of pass cavities. A circulator/isolator is also used on this duplexer.
The performance of this new duplexer also allowed me to permanently remove the ARR 70cm preamp from the receiver path.
The other duplexer has been a long time coming! The 2m VK5REX C D-Star repeater finally has it's own duplexer and is now fully operational. The home-brew 2m D-Star repeater has been operating with a hybrid two antenna setup for a while after it's installation, and for the last year or so has been off the air. The repeaters VHF folded dipole has been used for the MarineTraffic AIS receiver
Eventually I'd like to relocate the VK5REX C antenna higher on the tower... but that will have to wait until the weather is a little more predictable. For now I am more than happy just to have it on the air!
Thanks to Paul VK5BX, Tony, VK5RF, Matt VK5ZM and Arne VK5NEX.