[Scan-DC] Fairfax County: What's changed?

[freqhopping]

It has nothing to do with rebanding.  Fairfax's existing frequencies 
were already what they need to be.  They switched to an entirely new 
system, P25 vs Motorola Type II SmartZone.  The real problem is that 
they are now using P25 Linear Simulcast Modulation (8K70D1W), a type of 
CQPSK.  This is the same as the new Frederick Co MD system that many are 
having troubles monitoring as well.

For comparison Loudoun uses P25 Phase I C4FM (8K10F1E), P25 Phase II 
subscriber units [Harmonized Continuous Phase Modulation - 
H-CPM](8K10F1W) and P25 Phase II fixed-end 2-slot TDMA [Harmonized 
Differential Quadrature Phase Shift Keyed modulation - H-DQPSK] 
(9K80D7W) .   I don't have any issues with their system and I'm in range 
of several sites.

Fairfax on the other hand is difficult to listen to reliably at home, 
inside and out.  Simulcasting shouldn't even be an issue at home since 
I'm 15 and 25 miles from the nearest towers, and the nearest one is not 
likely to be received anyways because of terrain.   At work in Fairfax 
Co inside on the 5th floor in  a corner office with office with windows, 
it's really spotty.  But in the central lobby and even in the elevator 
it's better.  Outside on the ground or mobile in my truck I have no 
issues with it.

On 12/9/2012 8:14 AM, Dewey wrote:
> About the time you are describing (around July or August), I believe that
> Fairfax County rebanded.  Like a lot of the systems in our area, when moving
> to, or just rebanding, outside area coverage seems to be reduced.  This was
> discussed on RR a year or two ago when Baltimore City went to their rebanded
> system.  ***My take*** on the discussions is that the FCC wants these
> systems to be more "neighbor friendly" by focusing this power *into* their
> jurisdictions.
>
> Dewey
>
> -----Original Message-----
> From: scan-dc-bounces at mailman.qth.net
> [mailto:scan-dc-bounces at mailman.qth.net] On Behalf Of PeteL22151
> Sent: Saturday, December 08, 2012 23:52
> To: scan-dc at mailman.qth.net
> Subject: [Scan-DC] Fairfax County: What's changed?
>
> Fairfax County police, fire, etc., disappeared from my HomePatrol-1, RS
> Pro-106, and Pro-196units a number of months ago.  I went to RadioReference
> and reloaded what appeared to be an updated data set.  That started the
> services working again but the audio quality is significantly worse than
> before, inconsistent and frequently breaks up.  This same condition exists
> across all three scanners.  Signal strength seems to be fine, and some
> transmissions sound normal, but that's the exception rather than the rule.
> Any advice what's causing this?
>
> Thanks for any suggestions.
> Pete
>
> Sent from my iPad
> ______________________________________________________________
>