Anyway., let us go back in time to 1985. I was still working for various MSS and GESS (Motorola and GE radio service shops. There were "mobile" telephones around, we worked on them all the time . They were large heavy beasts that used a centronix cable to link a BIG UGLY handset to an even bigger UGLIER 2-way radio in the trunk. The best of them used a system called IMTS or "Improved Mobile Telephone Service". It was ""improved" from RCC which usually involved an operator dialing calls for you.
By the end of this era there were so may users on 5 or 6 usable frequencies, the only phones that could "grab a channel" had to scan for an open frequency by themselves. While everyone else had to wait - more. But, not to be unentertained, they all got to listen to your call - even if they did not want to. Otherwise the manual process had no chance on a busy day. You might as well just drive there and talk to them in person. Not to mention, that if you did get to make a call it was at 50 cents a minuet and a monthly charge of around $40 - even if you could never make a call.
So it was no wonder that, at some point, this wonderful radio was headed for the garbage can.
While in the subject of PTT, I have never figured out why people thought PTT on a cell phone was a great deal. In the day of this phone people could not get rid of that little button fast enough.
So in 1985 and then on, I assisted in the conversion of the nation to AMPS - yes - cell phones (Advanced Mobile Phone Service), from which eventually begot NAMPS, CDMA, PCS, GSM, SMS, 3G, 4G, EVDO, LTE, VoLTE, a lot of other letters and your smart phone.
I just found this thing on the shelf where it has resided for about 10 years and thought you might be interested.
P.S. The receiver is functional but the PA (power amp) has a bad OP transistor, not that there is anyone to talk to anyway.