foggycoder said:
I've heard a faint rumour that CW is used on digital voice platforms such as:
I know nothing about digital voice - does anyone know if that rumour is true and, if so, how CW is used on those platforms?
Well, D-Star is Icom's baby, DMR is just a generic digital voice voice protocol, and Fusion (A.K.A. C4FM) is Yaesu's baby.
All of these systems are generally implemented on FM VHF/UHF handheld transceivers, or mobile transceivers. None of them (as far as I am aware) were ever intended to use CW, just voice, though they can perform a CW identification (modulated audio, frequency modulated) as a means to identify the transmitter to non-digital listeners (normally government bodies).
Info around the web suggests that using CW (modulated audio) over any of the protocols you mentioned is an impromptu situation, there were no large scale organised groups leaping out at me anyhow.
The other info gleaned from searching was that the general method for transmitting 'CW' over the digital systems involved was done by simply keying an audio oscillator plugged in to the microphone socket of the rigs concerned.
I would imagine that any software/interfaces available that would allow access to the systems (all of them get 'trunked' from place to place via the internet), would also allow you to operate modulated CW without the need for a dedicated radio for any one system.
None of the systems are compatible with each other and generally any one radio will do only standard FM and one of the digital protocols mentioned above.
DMR ones are the lowest cost ones, possibly followed by Fusion(C4FM) and then D-Star. This is just a 'gut' feeling though based on numbers available of each of the units, and whether or not the system is open source or proprietary.
I'll try asking on one of the bigger digital forums and see if we get any feedback from it, unless someone on here knows that is!
73, Mark...
