AO-85 and Fox-1B/Cliff/D will start the transmitter "hang timer" when they detect the CTCSS. The tone must be again detected within 60 seconds in order to reset the hang timer else the downlink transmission will stop. By having your tone on your uplink signal all the time, each time someone keys it resets the hang timer.
Jerry Buxton, NØJY
On 2/28/2017 18:45, Andrew Glasbrenner wrote:
Actually the PL tone on AO-85 just turns the repeater on. Once it's on, there's no tone required until it times out...that's why you hear the noise on the uplink.