FBI Frequencies Searching in PA!!! Re: [FedCom] 167.490

[Ed]

a source who would know told me a few years ago that the FBI used a 
"voting" repeater system in philadelphia and other areas.  i.e., multiple 
repeater inputs receivers that compare the mobile signal strength at 
various locations, and control multiple repeater outputs accordingly.

this could explain why you heard different combinations of repeaters keying 
up simultaneously, at different times.

-ed


At 05:54 PM 3/28/06 -0500, you wrote:
>A lot of history goes back into researching how each region handles the 
>Repeaters.
>I can say way back, in New England, we thought the Repeaters were patched
>together, since at time we would hear 3-6 different Repeaters all key up 
>at the same time.
>
>A little Research and Scan-Search provided us with the information that 
>they Cluster the
>repeaters and use a Common input.   Yes...One input [same pl] but each 
>site was a
>different output.  If the Radio was a mobile, it would trip all the 
>repeaters, if they used a
>Portable, maybe one or two at a time.
>
>"Central" atleast in New England = 800, the Boston Office.
>
>Many RA's participate in a 9am Roll Call with Central.
>
>also , every 7-10 years, the Repeaters and Radio sites get moved.
>Both physically and Frequency wise.
>
>
>
>----- Original Message ----- From: "Terry Pavlick" <terry_pavlick at hotmail.com>
>To: "'Discussion of Federal Government Communications'" 
><fedcom at mailman.qth.net>
>Sent: Tuesday, March 28, 2006 5:09 PM
>Subject: RE: FBI Frequencies Searching in PA!!! Re: [FedCom] 167.490
>
>
>>Freq 168.425 and 168.725 (both using pl 167.9 when in the clear) are wide
>>area repeaters for the entire E PA, DE and NJ and Philadelphia area.  It
>>appears that at times both are keyed up simultaneously and at other times
>>not.  It just depends on how the system is activated.   168.725 appears to
>>be more local to me (in Delaware County based on signal strength.
>>
>>More active frequencies now are 173.9125 and 173.9375 (which based on the
>>level of activity) may be the newer set of repeaters.  PL is still 167.9 on
>>both freqs.
>>
>>I was always under the impression that "Central" was Philadelphia as there
>>were various other designators used in the past to identify the other
>>locations listed, i.e. "West" for Newtown Square etc.
>>
>>Based on recent monitoring, they appear to be switching over to P25 as some
>>testing has been heard recently from my location.
>>
>>There is sufficient activity in the Philadelphia area (even for mobile
>>monitoring) to keep the scanners busy.   Agreed that a lot of it is P25
>>encrypted.   My best suggestion for searching in the Philadelphia (Eastern
>>PA, Delaware and Southern New Jersey (even in the mobile) would be to search
>>from 163.5 to 173.9875 using a P25 capable scanner.  The P25 scanner is a
>>must.   UHF activity, while there, is limited.
>>
>>Hope this helps.
>>
>>Terry
>>Wallingford PA
>
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