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Post by F6CYK » Wed Nov 18, 2020 12:42 am

Hello to all. I am using a GD-77, an RD-5R and two GD-77S equipped with the OpenGD77 firmware as well as the CPS Community editor version R2020.11.08.02. Thanks to VK3KYY and to the whole team for the fabulous job.
Just one question regarding the GD-77S: is it possible to transmit a DTMF tone (for use of an EchoLink relay or similar, for example,) and if so, what to do and how to program it on?
Thank you in advance for your help.
73 from F6CYK/Tony

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Re: DTMF - GD-77S

Post by ve7mdt » Fri Nov 20, 2020 2:13 pm

I don't know about OpenGD77 on GD-77S, as I haven't looked closely.

However, just in theory, this has been doable on many radios without a keypad.

On some commercial radios, a channel can be programmed to send a DTMF sequence in the beginning of keying, usually for ANL functionality, but DTMF is DTMF. So if the user radio has spare channels, it can be programmed as such. It basically takes one sequence per channel, so think of it that way.

On some amateur radios, such as the Icom IC-2iA, Yaesu FT-1R etc, it's done by pre-programmed memories of these sequences ahead of time, by being recalled via the buttons or menus, and sent via it. So it still requires some sort of screen and buttons to do it.

I can imagine that the GD-77S is similar to a simple commercial radio in its form factor, and thus, in theory, could probably use the first method, if it's in the design. But given the priorities in many other things, esp on the digital voice DMR side, I am not sure if this will be implemented, since this is probably not a common request. And last I checked, the price diff b/w GD-77 and GD-77S is so minimal, there is no reason not go get the 77 if you need DTMF anyway.

I also have a second alternative method. There are DTMF audio devices that you can use in front of the radio. I have one that is also a calculator and a simple personal information management device. You can also use a smartphone with a DTMF generator app, and put the sound close to the radio's mic. Not an elegant solution, but might be useful if you only need it once in a while.
DMR radios: D878UV, D578UV-III (not arrived yet), XPR 5550, XPR 4550, XPR 7550, SL 7550, VXD-7200, CS-800D, RD-5R, GD-77, RT3s, MD-340 (not arrived yet)
DMR repeater: XPR 8400 UHF

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Re: DTMF - GD-77S

Post by F6CYK » Fri Nov 20, 2020 3:45 pm

Hello David and thank you for your answer. The advantage of the GD-77S compared to the GD-77 is to be able to be used "blind" in mobile, by manipulating only two buttons: the audio volume and the channel selector.
I have no difficulty programming one channel per DTMF code for a single frequency used. On the contrary, I see a clear advantage over GD-77 in this type of use.
The problem is that I don't know how to program the procedure for sending the DTMF code per channel, from the CPS editor of the OpenGD77.
Thanks again
73 from F6CYK / Tony

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Re: DTMF - GD-77S

Post by F1RMB » Fri Nov 20, 2020 5:11 pm


As I replied to you on Twitter this morning Tony, the DTMF contact support will be available on the next development version of the firmware.
You cannot set a DTMF contact per channel, it works like a contact list, so you need to browse this list and select the desired contact, then trigger the transmission.

73 de Daniel.

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Re: DTMF - GD-77S

Post by F6CYK » Fri Nov 20, 2020 11:26 pm

Hello Daniel. Thank you very much for your answer. After researching the forums well, I came to this conclusion. Thank you, in any case, for this confirmation and again well done for the work done.
73 and see you soon!

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