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| KNNq361 Bellingham City of (Fire Dept) http://www.interceptradio.com/bbs/viewtopic.php?f=1&t=9225 |
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| Author: | TOM [ Sat Nov 30, 2019 3:53 pm ] |
| Post subject: | KNNq361 Bellingham City of (Fire Dept) |
Up here in Vancouver I have been coming across 851.8125 Sys 325 Ran 2 NXDN, site 2 other freqs 851.2375-851.2625-851.6875-852.3375-854.5125 Is this starting to come alive ? I still hear fire on vhf ? Is it a replacement to this which has never seem to had activity ? https://www.radiotoolshed.com/apps/db/?sid=2704 |
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| Author: | nickcarr [ Sun Dec 01, 2019 2:19 pm ] |
| Post subject: | Re: KNNq361 Bellingham City of (Fire Dept) |
Yep... https://wireless2.fcc.gov/UlsApp/UlsSea ... ey=1302214 |
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| Author: | Craig H [ Mon Dec 02, 2019 5:54 pm ] |
| Post subject: | Re: KNNq361 Bellingham City of (Fire Dept) |
Aka: "System 325". That ( NXDN ) system has been running for a while now. Its kinda' a hybrid mixture utilizing both NPSPAC and non NPSPAC freqs. The NPSPAC freqs ( those below 854 Mhz ) only allow for a 12.Khz channel spacing. I'm no NXDN expert, rather just a hobbyist in this regard. Note the FCC emission designation of "4KO" in the license, which allows for as many as three channels per frequency in the NXDN mode. Note that above 854 Mhz, they can also still retain the 20K0 desingation. NXDN only requires a 4K0 window to operate (3.125kHz). Since they retained the 20K0, and adding the other emission designations as shown, there are FCC letters of agreement attached to those licenses that allow them to run a 4K0 on the center frequency as well as 6.25kHz above and below center. Can’t do that below 854 Mhz in the NPSPAC band because the 12.5kHz channel step protocol is in place there. The 20K0 won’t fit. I don't reside up that way - and it is extremely difficult for me to hear anything from my locale. I believe they may also employ some additional (non NPSPAC ) freqs above 854 Mhz at other tower sites using the "4KO" designation too ? Maybe another ( northern ) Intercept member here can do some additional field "bunnery" actions to verify what I've described here ? The Squalicum site is running the both ( NXDN ) upper and lower side of 854.5125 ( 854.50625 and 854.51875 ). The system is "Transmission Trunked" instead of "Message Trunked", where each transmission advances to the next open channel. If it’s the only conversation going on at a site, then each transmission is advanced to the next channel at the site, skipping the control channel (e.g; channel-2): 1) 852.33750 2) 851.81250 3 ) 851.26250 4) 854.50625 5 ) 854.51875 6 ) 851.68750 7 ) 851.96250 I hereby pass the shoe. Bueller ? Bueller ? |
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