Jeff Liebermann wrote:
TNC. There's also the stuck transmitter on commercial and
public safety frequencies. Those are fun and gets us plenty of points
from the various agencies. Extra credit to the local comm shop that
likes to defeat the timeout timer, for no obvious reason.

It does not seem the public safety radio devices always had this
timeout timer either.
Before the public safety services here switched to a digital system,
they used NBFM equipment from companies like Motorola, and it was very
common to hear stuck transmitters that blocked an entire repeater channel.
(which often consists of multiple receivers and transmitters over a city area)

Police used mobile transceivers in the cars on VHF and portables on UHF
so it usually was possible to alert the users on the other channel and
hope the stuck PTT key was found that way, but on major events like
queen's day it often happened that the portables channel was jammed for
half an hour or so before the culprit was found.

Of course the equipment was aging by that time, it probably was from
the eighties. Now they are all on TETRA and AFAIK that system allows
the operator to just tune out stuck transmitters or devices that fell
into wrong hands.