ATIS was a old signaling format proprietary to Motorola. FDNY at one time used it however my understanding is it was never compatible with mdc1200 decoding on displays minus a console capable of decoding signaling of various formats.
The Ht1000 and Visar had MDC1200, GESTAR, dtmf, 2 tone decode and ATIS as options.
I'd imagine they are mdc1200 now in NYC but I know they mute the dos at the voter level so even of you wanted a long non muted mdc tone receiving you may get a muted mdc tone. Not sure if FDNY uses voter muting at the comparator level but I'd imagine they would if it's done on other levels.
I do know at one time in A version HT1000s selecting ATIS and enabling muting would kill nasty bursts from improper programmed units or quantars that didnt have proper pl settings. Though in B, C, DN versions simply adjusting the mdc settings to mute and adjust the timers would yield this issue.
Any how it is just a different type of signaling at one time and mdc1200 became the norm standard for Motorola.
What you ask is pre/post mdc1200 or signaling like GESTAR or ATIS.
It varies on the system where you go. Some use pre, some use post, some use both depending on how the system is setup and what the system administrators want.
As for your own frequency if it's licensed to you, you can do whatever you want.
If it's gmrs frs I won't get into the debate of what is legal what isn't. As for other systems such as public safety it is rule of thumb to have anything programmed by system administrators, techs, or authorized parties to do such.
