[Scan-DC] Metro: DC Fire and EMS radio encryption blamed for failure in de - DC News FOX 5 DC WTTG

[Dewey]

Well said, and I would tend to agree.  Concerning the "non-functioning"
direct channels, I can't help but wonder if the personnel in the tunnels may
have *assumed* that the channels weren't working if they were not being
heard by the repeater truck up on the street level.  Remember in addition to
being a multi-level station, they were a little ways into the tunnel and may
not have had enough punch to get up to the street opposed to setting up a
relay at the platform.  Radio "functionality" is probably at the very
bottom, if on the list at all taught to public safety personnel.  When I was
in the academy, we were all taught that the radios did not work from garage
type structures, especially underground.  They went as far as to explain
that's how the very first woman sworn police officer, MPD Officer Gail A.
Cobb, was killed when she couldn't radio for backup after stopping a
suspected armed robbery suspect in a garage.  However, no one explained, or
probably even knew the way radios operate on a repeater system.  I will
always remember a chase that went out I-66 beyond the beltway, and a
sergeant who was a good friend jumping on the radio that he was responding
to I-66 and the beltway to setup a "relay".  I think most, if not all of us
here know how that is not going to work using everyday 5 MHz split repeated
radio systems.  Oh well, enough Monday morning quarterbacking from me, but
that is the only thing I can come with to explain how DIRECT communications
will not work outside of a nuclear explosion.

Dewey

-----Original Message-----
From: Scan-DC [mailto:scan-dc-bounces at mailman.qth.net] On Behalf Of Joel
Kahn
Sent: Friday, January 23, 2015 16:01
To: Jeff Krauss; Scan DC
Subject: Re: [Scan-DC] Metro: DC Fire and EMS radio encryption blamed for
failure in de - DC News FOX 5 DC WTTG

Not at all, the leaky line repeaters are used to carry all comms on the
repaeted frequencies.  Since WMATA went to the TRS I do not know if they
upgraded the repeated frequencies from 160s to 480s.  I know that when I
rode the system in November, my scanner was picking up the OPs and MetroPD
on the old 160 frequencies just fine, as was DCFD on 800Mhz system the
entire time I was underground.

I would suspect, like has been mentioned here, that the 700MHz channels have
not been added to the repeater equipment, not that the encryption, per se,
was the culprit.  If it was the encrypted fireground channels, then they
should still have been able to communicate on 01 and 02 that are not
encrypted.  The radios did not work at all underground.

 
Joel R Kahn


________________________________
 From: Jeff Krauss <jeff at krauss.ws>
To: Joel Kahn <jrkahn at att.net>; Scan DC <scan-dc at mailman.qth.net> 
Sent: Friday, January 23, 2015 3:31 PM
Subject: Re: [Scan-DC] Metro: DC Fire and EMS radio encryption blamed  for
failure in de - DC News FOX 5 DC WTTG
 

If that were the case, WMATA police and the train operators would not 
have been able to communicate with their dispatchers.
Nobody has claimed that problem occurred.



At 03:17 PM 1/23/2015, Joel Kahn wrote:

>The Leaky Line antenna system is connected to repeaters/boosters 
>througout the system.  There is a comms closet in every station (at 
>least below ground).. This antenna carries signals for not just 
>emergency operations, but regular train & operations communications as well
>
>
>Joel R Kahn
______________________________________________________________
Scan-DC mailing list
Home: http://mailman.qth.net/mailman/listinfo/scan-dc
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Scan-DC at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html