Talkback on 144.750MHz

What's coming up in the future? Ideas or suggestions welcome.
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Talkback on 144.750MHz

Post by admin » Wed Dec 09, 2015 8:51 pm

The next addition (and the item being worked on starting December 2015), is to add talkback on 2 metres via the designated ATV frequency.

The addition will hopefully happen during early 2016 and the receiver unit is currently being built. The receive frequency will be the normal talkback of 144.750Mhz, with a CTCSS access frequency of 118.8Hz. The CTCSS frequency has been chosen since it is not used in or around West Yorkshire for voice repeater access, and is therefore less likely to interfere with GB3YT normal audio operation unless intentionally set.

The 2m audio will not be relayed over GB3YT unless an active 'locked' digital 23cm signal is being received along with a 2m signal on 144.750Mhz with CTCSS of 118.8Hz. Talkback will appear on only one audio channel (right) so it can be nulled out if necessary - original GB3YT repeater audio will appear on the other channel (left). Standby audio will be stereo fed to both L/R audio channels (no 2m talkback if no 23cm signal). Streaming audio will be the same as over-the-air transmitted audio.

The 2m receive antenna is likely to be just a simple mag-mount vertical. This specification may change before installation.

Any comments appreciated.

Kay G8NZR

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