[FedCom] Re: P25 Digital For or Against?

[Dave J]

Hi Ken, and the group.

You've put your finger on a digi downfall.

As a digi and analog user (Vol. EMT and Firefighter) I've some experience in
this area.  Our state went digi for most of the State Agencies and many of
the local and county EMS, Fire, and Law services over the last two or three
years.
My county's agencies currently use both depending on to whom we are talking.

An analog radio of equal Tx power, Rx sensitivity, and antenna seems to
enable comms over a slightly longer range but with some static if you're in
the "threshold area".  The static increases with increase in range until the
signal finally becomes unreadable (below the noise level).

The digi sets will remain clear as a bell (how-be-it a funny sounding bell)
until they simply drop out completely.

Analog = Longer range with need to accept increasing static at the longest
ranges.

Digi =  Clearer signal until drop-out, but noticeable shortening of range
due to lack of "weak signal" (thru the noise) reception.

Myself, I'd rather have the capability of working a weak signal station (as
opposed to not hearing them at all) even if I had to concentrate to
determine what they were saying.  It could be critical comms (accident down
in a "hole") and they not able to improve their location while remaining
with the pt.

Dave J
sd0044 at gwtc.net

=========================================
----- Original Message ----- 
From: "Ken" <rfinder1 at verizon.net>
To: "Discussion of Federal Government Communications"
<fedcom at mailman.qth.net>
Sent: Monday, October 16, 2006 16:37 PM
Subject: Re: [FedCom] Re: P25 Digital For or Against?


> Seems to me in monitoring digital, that as long as you have the remote
> base/repeater facilities close
> to the user, than it works fine.  Once you start getting away a few miles
> (especially with digital) & a portable radio there's problems.  Also
> portable to portable can have some problems.   With anlog NFM, you might
get
> some noise in the system, with digital you might not hear anything at the
> other end other than some tones/hash when the system is unable to decode
the
> voice.  I can remember in rural Michigan on a 173.XXXX frequency, using a
1
> watt portable FM being able to talk about 20 miles to a remote base
station
> with the antenna mounted on  the facilities water tower.  Would be
> interesting to see some side by side comparison today with a 1 watt
digital
> & analog w/t (which I don't think they make a 1 watt digital w/t).
>
> http://mrtmag.com/mag/radio_debate_digital_standard/
> http://www.p25.com/resources/P25TrainingGuide.pdf
>
> Comments from others who monitor P25 & NFM federal?
>
> Ken