posted in: DMR, GD-77, Ham radio | 1

Thanks to Alex DL4LEX, FM DTMF for the OpenGD77 is now functional

—————————– Update 8th November —————————–

VK3YNV has been some tests of the DTMF and it looks like the tones are currently over-deviating the FM modulation.

This probably apples to both the DTMF and the Tone burst and possibly also to the CTCSS tones

I’ve done some initial investigation of the problem, and calibration values for the DTMF, Tone burst and CTCSS value are not being read from the Flash memory and being applied

The data sheet does not seem to contain any information about how to set the DTMF or Tone burst deviation, but its possibly the same register as the CTCSS control register settings.

I will need to do some R&D during the weekend
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DTFM tones can be transmitted on FM by pressing the number and other keys on the keypad.

There is also audible feedback though the speaker.

Alex also sent me another modification, which I discussed with him.

If the TalkGroup has been entered manually, pressing the Left or Right arrow keys first removes the manually entered TalkGroup.
Then pressing Left or Right again, cycles through the TalkGroup list as normal.

I have updated the Tier2 latest version with this and other changes

  1. Ken, M1DYP

    hi Roger, with thanks to you and Alex, and all others involved in this wonderful project. Initial turn on after firmware update (done with community software) seem to mute FM signals, but a quick power cycle restored operation and everything is good now, many thanks.

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