June 27 2015
Thinking outloud about radio systems
This popped into my brain last night
Lets say that Anytown PD has 2 repeater channels - Channel 1 is 155.25
R with 153.74 input - Channel 2 is 155.31 R with 153.80 input
Lets say that each police car has a MO3
Lets say that Anytown PD also has 4 UHF channels - 453.00 and 458.00 -
plus - 460.00 and 465.00. There are receivers on 453.00, 458.00,
460.00, and 465.00 at the police station.
When the first police car arrives at an incident, the MO3 is set to
receive on 153.74 and to transmit on 453.00. This is essentially a new
remote receiver site that has gone into service right at the incident
scene. It pretty much guarantees that any portable radio transmissions
at the scene will be relayed back to the dipatchers (because they have
a receiver on 453.00 - and it is tied into the voter system for 155.25
R.
The second police car that arrives at the scene sets up his MO3 to
receive on 155.25 and to transmit on 458.00. This MO3 is intended to
capture any messages on "direct" and to relay them back to the
dispatchers.
The third police car that arrives at the scene sets up his MO3 to
receive on 153.80 and to transmit on 460.00.
The 4th police car to arrive at the scene sets up his MO3 to recieve
on 155.31 and to transmit on 465.00
We now have a system where all portable radio messages will be heard
with a very high probability of success - everywhere in the world.
Note - the UHF channels can be replaced with a TRS - or the UHF
channels can be replaced via ComCast Wireless Nodes - or the entire
deal can be replaced with some system that utilizes the wireless nodes
in every house and office.
The reception of the "direct" channels by the dispatchers might be
problematic - maybe not - maybe a digital delay is needed to kill
feedback and echoes - but relaying of the "direct" channels to the
dispatchers is solely intended to keep the dispatcher from stepping on
units that are using "direct" - this could also be partially
accomplished by putting 155.25 and 155.31 receivers at the police
station.
Of course - using proper radio procedures can help solve this issue
also. When the dispatcher hears someone say "Unit XXX go ahead on
direct" then the dispatcher should know enough to stay off the channel
for a while.