GB7JB HardwareThe principle system for GB7JB is of course the repeater itself. This is a Motorola DR3000, the specification for which is shown below.
The TX and RX sockets are connected to a normal wide bandwidth duplexer, which is all that is necessary to allow successful operation, at the 9 Mhz split, between the input and output frequencies.
In the image above, you will see a typical duplexer lying on top of the repeater unit.
You will also note that, in the bottom left had of the unit, there is a mains power supply, this of course is basically redundant at the "JB" site, but it does enable safe connection to the high current and fully regulated 13.8 volt dc feed, since the entire site is run from a 24 volt battery system, which is float charged by a 35v / 45v Solar Power system.
|Basic System Schematic|
The output of the duplexer is then connected to the antenna, via a lightning arrestor and 50 feet of LRM400 coax.
The system is single antenna working, with a 4 stacked dipole array, similar to the image shown below.
This page is still under construction, and it's content and layout may well change without notice and in due course..