Use of Data on 70cm


Oct 25, 2018
North NJ, Northeast PA
Hi all,

I am not sure where to post this. It has to do with general amateur radio rules, the use of digital voice, and the use of digital data.

I am wondering what the legalities/roadblocks are of using Motorola's ASTRO25 or ASTRO Text messaging and selective calling services. If I were to be experimenting with a few portables, am I allowed to sent text messages between the two radios or send selective calls(I believe this type of data is 9.6kbps C4FM)? Alongside this, how should a radio identify if using data like this. Should the callsign be in the message or should you say it in analog or digital voice? I am trying to look into the whole legality of this and I want to make sure it is allowed before I try anything. I cannot seem to find a concrete answer in the FCC part 97 rules.

Any help is appreciated!


Lead Wiki Manager
Super Moderator
Jul 18, 2004
Brownsburg, Indiana
§97.119 Station identification

b) The call sign must be transmitted with an emission authorized for the transmitting channel in one of the following ways:
(1) By a CW emission. When keyed by an automatic device used only for identification, the speed must not exceed 20 words per minute;
(2) By a phone emission in the English language. Use of a phonetic alphabet as an aid for correct station identification is encouraged;
(3) By a RTTY emission using a specified digital code when all or part of the communications are transmitted by a RTTY or data emission;
(4) By an image emission conforming to the applicable transmission standards, either color or monochrome, of §73.682(a) of the FCC Rules when all or part of the communications are transmitted in the same image emission.

The FCC has stated in the past that identifying using a digital voice mode is allowed. The FCC also accepts station identification using CW, RTTY, PSK31, FT8, etc., when operating using those data modes.