[Scan-DC] Fairfax Dispatch - 460.575

[jay dehm]

SCADA.. Is that what I am hearing in the VHF hi-band 170-174.. I get
some signals that sound bleepy and rtty-like.. faintly from my
location in the suburbs of DC..

any guesses?

-Jay

On 7/10/06, Shawnerz <shawnerz at yahoo.com> wrote:
>
> Randy,
> I don't monitor the system, but there are a couple
> possibilities:
> 1.  It could be interference.  For whatever reason,
> the base station "sees" the interference (intermod,
> adjacent channel, whatever) as a valid signal and is
> repeating it.  In the scenario, the system controller
> would show the repeater as busy and it would not be
> availible for use while the interference is active.
> 2.  It could encrypted traffic and you're hearing the
> encrypted output.
> 3.  It's analog SCADA (Station Control And Data
> Automation) traffic.  For example, in Montgomery
> County, they use SCADA units to report water well
> alarms, flow rates and stuff like that.  The units
> have their own talkgroup and the demodulated audio
> resembles static to the untrained ear.
>
> I hope that helps.
> -Shawn
> --- Randy Benn <randybenn at gmail.com> wrote:
>
> > I've recently been monitoring FFX dispatch on their
> > conventional freq. rather than the TRS.  I've
> > noticed a strange behavior in that the squelch will
> > frequently break, but there is no audio that
> > follows.  This has been verified on multiple radios
> > and in multiple locations, so it doesn't seem to be
> > related to interference in any way.  I haven't
> > noticed this behavior on 4A on the TRS, so it seems
> > to be limited to the conventional alerting freq.
> > Anybody know what might be going on?
> >
> > Randy
> > _______________________________________________
> > Scan-DC mailing list
> > Scan-DC at mailman.qth.net
> > http://mailman.qth.net/mailman/listinfo/scan-dc
> >
>
>
> __________________________________________________
> Do You Yahoo!?
> Tired of spam?  Yahoo! Mail has the best spam protection around
> http://mail.yahoo.com
> _______________________________________________
> Scan-DC mailing list
> Scan-DC at mailman.qth.net
> http://mailman.qth.net/mailman/listinfo/scan-dc
>