InterceptRadio.com Forums

I seem to lose Seattle once I get past 45th S/B on I-5.

_________________
"Lawyers, Guns and Money"

Im curious,according to the FCC they have a repeater pair licensed 155.970/159.075 at 1900 5th in Seattle. My WSP site map lists this site as "Westin"

No big thing. The hotel is a good site to cover the downtown area -- with a repeater on the "State" channel. Since the hotel has rental space available for two-ways - the WSP rented a spot on the roof. The WSP was looking for coverage of the freeways and not the city of Seattle.

is it used as an 'area' channel for downtown?

No it is not. Its used as a standby or fill-in. The downtown area has poor coverage from any of the other WSP sites. It is not used as a dispatch channel. Its not an area dispatch channel. It is a back up channel.

The WSP now holds the State Licence for the LoJac system on 173.075 and has applied for a new Statewide channel for inter-operations communications on 155.3625 using both analog and DIGITAL emissions.

This is interesting.

There are 5 VHF freqs and 8 UHF frqs (4 pairs) assigned for nationwide interoperability. This frequency is not one of them. Maybe WSP intends for "Statewide" interoperability use as opposed to Nationwide interop use.
I guess this is in addition to LERN.

For those interested, the National Interop freqs for VHF/UHF are:
VHF
151.1375
154.4525
155.7525
158.7375
159.4725

UHF
453.2125
453.4625
453.7125
453.8625
458.2125
458.4625
458.7125
458.8625


For FED Interop use, the following from IRAC (the FED freq. coordinator):
http://www.apcointl.org/frequency/downl ... 1061-2.htm
-or-
http://www.lubbockradio.net/irac.htm

LAW ENFORCEMENT PLANS

1. Frequencies 167.0875 MHz and 414.0375 MHz are designated as National Calling Channels for initial contact and will be identified in the radio as indicated in paragraph 2 below. Initial contact communications will be established using analog FM emission (11KF3E). The agency in control of the incident will assign specific operational channels as required for incident support operations.

2. The interoperability frequencies will be identified in mobile and portable radios as follows with Continuous Tone-Controlled Squelch Systems (CTCSS) frequency 167.9 Hz and/or Network Access Code (NAC) $68F:

VHF PLAN - Mobile Mobile
Identifier Transmit (MHz) Receive (MHz)
Natl Call 167.0875 (Simplex) 167.0875
Inop 1 162.0875 167.0875
Inop 2 162.2625 167.2500
Inop 3 162.8375 167.7500
Inop 4 163.2875 168.1125
Inop 5 163.4250 168.4625
Inop 6 167.2500 (Simplex) 167.2500
Inop 7 167.7500 (Simplex) 167.7500
Inop 8 168.1125 (Simplex) 168.1125
Inop 9 168.4625 (Simplex) 168.4625

UHF PLAN - Mobile Mobile
Identifier Transmit (MHz) Receive (MHz)
Natl Call 414.0375 (Simplex) 414.0375
Inop 1 418.9875 409.9875
Inop 2 419.1875 410.1875
Inop 3 419.6125 410.6125
Inop 4 414.0625 (Simplex) 414.0625
Inop 5 414.3125 (Simplex) 414.3125
Inop 6 414.3375 (Simplex) 414.3375
Inop 7 409.9875 (Simplex) 409.9875
Inop 8 410.1875 (Simplex) 410.1875
Inop 9 410.6125 (Simplex) 410.6125

3. All applications using these allotted frequencies shall be affixed with Record Note Sxxx - This assignment is for a joint law enforcement requirement pursuant to Section 4.3.X of this Manual.

INCIDENT RESPONSE PLANS

1. Frequencies 169.5375 MHz, paired with 164.7125 MHz, and 410.2375 MHz, paired with 419.2375 MHz, are designated as the calling channels for initial contact and will be identified in the radio as indicated in paragraph 2. Initial contact will be established using analog FM emission (11KF3E). CTCSS will not be used on the calling channels to ensure access by stations from outside the normal area of operation. The agency in control of the incident will assign specific operational channels as required for incident support operations.

2. The Interoperability frequencies will be identified in mobile and portable radios as follows:

VHF PLAN
Mobile Mobile
Identifier Transmit (MHz) Receive (MHz) CTCSS
VHF Calling 164.7125 169.5375 None
VHF 1 165.2500 170.0125 As required
VHF 2 165.9625 170.4125 As required
VHF 3 166.5750 170.6875 As required
VHF 4 167.3250 173.0375 As required
VHF 5 169.5375 (Simplex) 169.5375 As required
VHF 6 170.0125 (Simplex) 170.0125 As required
VHF 7 170.4125 (Simplex) 170.4125 As required
VHF 8 170.6875 (Simplex) 170.6875 As required
VHF 9 173.0375 (Simplex) 173.0375 As required

UHF PLAN
Mobile Mobile
Identifier Transmit (MHz) Receive (MHz) CTCSS
UHF Calling 419.2375 410.2375 None
UHF 1 419.4375 410.4375 As required
UHF 2 419.6375 410.6375 As required
UHF 3 419.8375 410.8375 As required
UHF 4 413.1875 (Simplex) 413.1875 As required
UHF 5 413.2125 (Simplex) 413.2125 As required
UHF 6 410.2375 (Simplex) 410.2375 As required
UHF 7 410.4375 (Simplex) 410.4375 As required
UHF 8 410.6375 (Simplex) 410.6375 As required
UHF 9 410.8375 (Simplex) 410.8375 As required

:D 155.37 and the NEW frequency: 155.3625 are BOTH LERN channels. 155.3625 is both analog and DIGITAL. Great inter-ops info. Thanks.

It sounded like this was the case. Although digital vs. analog will play on either freq. Digital doesn't care what freq it is on any more than analog.

The new ICOM P-25 radio is about to release. It has four programmable operating modes per channel.
>Analog RX/TX
>P-25 Digital RX/TX
>Mixed Mode RX w/ Analog TX
>Mixed Mode RX w/ P-25 Digital TX

By programming a "mixed mode" option, the radio will receive either Analog FM or P-25 Digital signals automagically. I have a feeling all P-25 radios do this since the P-25 standard does require backwards compatibility with analog FM.

Incidentally, the P-25 modulated signal is very similar to FM. It is called "C4FM" and is a signal that deviates just like FM, however it only deviates to 4 specific points, rather than the continuously variable deviation required for an analog FM signal. Makes manufacturing a mixed mode receiver a little more straightforward.