Bill Powell wrote: > I have an opportunity to establish remote control for several of our > ham repeaters that are co-locates with our county microwave system. > There are plenty of "spare" $W E&M channels available with the switch > from an analog to a digital system. > My objective is to remove a little RF from our RACES room and > consolodate the current mess into something simple. > Ideally, I can hack together a simple pushbutton operated panel: push > to select a particular repeater. Think of the old office phones. > Anyone out there doing this? > Suggestions? > Traps?
Well, you will want to use the E&M part for PTT and you can also use the reverse path for a COR-based activity indication. Just remember it's all 600 ohm audio, keep levels down so that the max level that can possibly be generated is roughly under 0 dBm, but above -20. And the E&M is referenced to MINUS 48 volts, so watch your grounds and BE CAREFUL! It'll knock ya on yer butt if yer not. You won't really need to "switch" between rptrs. Bring all the audios in to a mixer, with maybe volume controls for each, or try to invent some sort of select/unselect arrangement like is done with dispatch consoles. Then just have a row of pushbuttons for each PTT, mic audio can be connected to all through it's PTT switch (actually a relay would be more reliable). You can even get ingenious and 'patch' repeaters together on-the-fly! -- Jim Barbour WD8CHL
