[FedCom] TSA at Portland (Maine) Jetport, et. al.

[Steven Donnell WA1YKL]

Hi, The 170.625, at least heard here in S NewHampshire is the output of a
Border Patrol rpt, in/near VT; Ive units surveying vehicle traffic along rt 91.
Some is clear, mostly encrypted, P25 mode.

Are you using a P25 scanner?, as P25 and (analog)DES sound quite similiar. One
easy way to tell, at least w/ a repeater is w/ P25, the idle/tail of a rpt
transmission will have a "buzz" sound where the tail end of a DES tx has that
distinctive high pitch whine.    Steve


HornSmoke wrote:

> Folks, I dropped off family at the Portland Jetport (PWM) yesterday morning
> and got a confirmed TSA  on 172.150. There was a split-second drop of
>  encryption, and a DPL of 145 registered. This happened twice, which
> leads me to believe it is accurate. I was sitting 500 meters or less
> away from the terminal, and had it full quieting.
>
> Extensive traffic in Maine on 170.625; Customs/BP? Mostly encrypted; PL
> tone of 151.4 shows up, even WITH the encryption, about 70% of the time
> there is a transmission. One would think that they'd hide the PL in the
> encryption process.
>
> "Foxtrot" units are the primary users on the 170.625. I'm quite sure
> there are multiple repeaters with this output positioned along the
> western Maine border with New Hampshire and Canada. I'd welcome any
> "input as to the input" to this freq. I also suspect that there is a
> linked system, with varying input PL's matched to the standard output PL
> of 151.4, much like our civilian LifeFlight helo ambulatory transport
> here in Maine that utilizes multiple towers on 453.650R with a universal
> pl tone output of 103.5. The +5 MHz input has a different PL for each
> tower. Could any of the Group Gurus enlighten us as to any known federal
> S.O.P.'s along these lines? Or, is it up to each individual radio shop
> how the system is programmed?
>
> To codify my rambling questions, they are as follows:
>
> 1) Input to 170.625?
> 2) Possible linked repeater system on 170.625? New Hampshire monitors
> could especially help here.
> 3) Programming Standard Operating Procedure in federal radio shops, as
> there is a proliferation of "cross-agency" usage.
> 4) Group experience on how PL/DPL tones are either suppressed or "in the
> clear" when encryption is used.
>
> Thanks in advance for any help.
>
> Best to the Group from wintery Maine,
>
> Loren
>
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