CHP going digital on low band??

mmckenna

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My viewpoint I think analog has been working soo much better then digital
And there is no requirement for them to change. No narrow banding requirements. What they have works in most places.

CalTrans is using a lot of 800MHz now, but all their trucks I see around me, even the brand new ones, all have low band whips and Kenwood TK-690's installed.
 

russbrill

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Yeah, compared to most provinces, California is small. You got me there.

California has some "Statewide" VHF networks, but they don't cover the whole state. Just too many deep valleys for it to work well enough. Add in there are too many silos that agencies don't want to share systems. Maybe some day that'll change, but I don't see it happening any time soon. CalFire has their system. Department of Fish and Game has their system, etc…..

VHF Low band works.

And then getting enough clear VHF pairs would be difficult. I'm trying to get a few pairs for a system upgrade, and it's difficult. Not impossible, but a lot of the pairs we are finding are very close to existing systems where we'll have to share sites.

Budget is an issue, too. That's a lot of money for new sites, new repeaters, etc. Would take a lot of years to roll out a system that big. Simply replacing the existing CHP radios is being spread out over 3 years. Building a new statewide multi-channel VHF High network would take a very long time.
The Low Band system offers the best value per dollar spent.. I don't think anyone that operates a Statewide 800 MHz system is doing it as cheaply as the CHP System....
 

RFI-EMI-GUY

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Since when does noise only affect digital signals?
At low band, the propensity for signals to propagate much further than intended is pretty great. Two low band signals desired and undesired with PL tones and carrier heterodyne mixing will be annoying and the FM capture will slowly cause one or the other to come through. With P25 the audio packets will get lost and you will have a lot of unintelligible garbling and racket if anything at all.

Its garbage either way, but with digital it is simply a weird malfunction.
 

djones87401

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Kenwood is the only Manufacturer making a low band mobile. Also they did NXDN for the low band only to meet digital requirements of FCC future mandates. I do not know if they will ever go low band NXDN as Kenwood does not offer any Low Band repeaters. So maybe in the future. Also Kenwood was selected because you can monitor 4 RF bands or radios at same time with 4 speakers and 1 control head. CHP is switching to the Viking VM7000 mobile from EF Johnson. Amazing radio with much to offer. CHP has no intention of leaving low band any time soon. CHP also selected Pyramid for mobile vehicle repeaters or what they call extenders. Because Kenwood is only manufacturer willing to offer P25, NXDN, and DMR is same radio it's hard not to select them. More states are switching because cost and better options.

I am a dealer from NM and just visiting the bay area and found this and wanted to chime in. I know little bit about this award from some dealer friends.
 

K6CDO

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Let me make a prediction. This is the ONLY change you'll POSSIBLY see happen with CHP in the future (notice that this isn't certain)...

When the California C.R.I.S. system is complete, CHP can simply subscribe (and spend millions purchasing equipment).
.

No need to purchase equipment. CHP already has the equipment needed (mobiles and portables).
 

RFI-EMI-GUY

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I cannot imagine the FCC mandating narrowband for VHF low band. There is simply no demand. They would be better off making an effort to realocate VHF High band into duplex pairs and paging blocks. They missed this opportunity during the narrow banding when they could have repacked certain blocks.
 

petnrdx

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And there are not enuf VHF channels available for CHP to cover the state. Try to get even a couple freqs in a populated area. Good luck with that... There are WAY more people than BC. Many thousands of miles of paved roads more than BC. To cover CA in anything other than Low Band they would have to add hundreds of sites. "Someday" they might do it. But I think that is more like 20 years away. Just my opinion.
 

Paysonscanner

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And there are not enuf VHF channels available for CHP to cover the state. Try to get even a couple freqs in a populated area. Good luck with that... There are WAY more people than BC. Many thousands of miles of paved roads more than BC. To cover CA in anything other than Low Band they would have to add hundreds of sites. "Someday" they might do it. But I think that is more like 20 years away. Just my opinion.
My late hubby was a civil engineer for a small county on the west side of the Sierra Nevada. He had some duties related to electronic sites. Sometimes because the county had comm facilities at sites, where county roads would be used to access sites, where new roads were built to access sites or to upgrade access to sites and being part of the permitting process when facilities were installed. Some of the county's sites were on private land, some on USFS land, some on BLM land and even one in a national park. He said that so many people assume that if coverage is needed for higher frequencies, such as the 700-950 range requiring a bunch more sites that those can get built. This is not realistic as there are a huge number of constraints in building new sites. There are environmental issues, access issues, land ownership issues, neighborhood issues, power source issues, public agency policies and resource management plans, geology issues . . . . . . I don't recall all the issues he dealt with. Comms in the mountains are quite different than they are in flat lands in cities and the Central Valley of Calif. People too often assume that additional sites can be installed to support whatever technology public agencies, private companies and individuals want to use. Hubby said that is a very poor assumption. He told me that the CHP looked into going to higher frequencies in San Diego County, the 450-470 range (?) and that they would need 4 times the number of sites to provide the same coverage VHF Low was already providing. Somewhere in his home file cabinets I think he printed thiese study. San Diego County has some interesting topography but compared to the Sierra it is pretty gentle so imagine CHP trying to go to a 700 meg statewide system. If they just needed 4 times the sites for 450-470 meg can anyone grasp what 700 would need. If they needed 6 or 8 times the number of sites they might not be able to build half to three quarters of those. There were many places in our county that got some major recreation visitation with paved road access, commercial power, small resorts, etc. that don't have any cell phone coverage and likely never will due mainly to environmental issues, mostly scenic intrusion. People who live or visit the mountains don't want to look at ugly towers on every horizon.
 

mmckenna

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I've been struggling trying to get some VHF pairs for our pd for while now. No luck.

having an 800MHz conventional repeater co-located with the pd VHF high band system really proves the coverage differences.

VHF low is here for a long time. Might see some migration to "system of systems" approach, but Payson said, there is no way they'll get enough sites to ever make it a true statewide thing.
 

Paysonscanner

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And there is no requirement for them to change. No narrow banding requirements. What they have works in most places.

CalTrans is using a lot of 800MHz now, but all their trucks I see around me, even the brand new ones, all have low band whips and Kenwood TK-690's installed.
I moved from Calif. in the fall of 2018. Hubby and I lived in a small Sierra foothill county. We had some neighbors who worked for Caltrans and some were CHP officers. The Caltrans supervisors had low band radios in the pickups and the large dump/plow trucks did not. The Caltrans people said they had those low band radios to communicate with the CHP. In good snowstorms the coordination between the two agencies was intense and we enjoyed listening to their ops. Large equipment and their operators did not have CHP radios. That was 1 1/2 years ago so something could have changed. Are you seeing low band antennas on large trucks/graders/loaders now?

I have one observation that has not been brought up here having to do with some type of statewide 700/800 radio system. Take a look at State Parks, who finally gave up trying to get 800 meg coverage in their North Coast Redwoods District that includes Del Norte, Humboldt, Siskiyou and Mendocino Counties. They opted to go with two VHF High frequencies with lots of analog repeaters because pine needles attenuate 700/800 meg signals. We heard that different species of trees have needle lengths that are just right for affecting those wavelengths. I don't know the status of the Caltrans 800 meg system conversion up there, it's their District 1 and maybe parts of D2 as well. They were the last Caltrans districts to start switching from low band. I know that Hubby and I drove up Highway 199 to Oregon about 4-5 years ago (follows the Smith River) and he remarked that Caltrans had licenses for ground level repeaters to cover the entire highway. Hubby joked that they had licenses for every major curve in the road. I think they were proposing 20 or more of these ground level sites. This is practical, on the ground, experience that illustrates how difficult constructing a statewide 700/800 meg system would be.

EDIT For those who live outside Calif. I should have mentioned that both Caltrans and State Parks began their switch to statewide, analog, non-trunked 800 meg systems around 1981 or 1982. Now, almost 40 years later, I don't think Caltrans has been able to fully switch over to 800 in northern CA. They have trunking systems for the metro areas of Southern CA (Districts 7, 8, 11 & 12) and for SF Bay Area (District 4), but it's conventional analog everywhere else. The north coast with the dense tree cover has challenged radio techs. State Parks gave up and just happened to find 2 repeater frequency pairs, which they would not have been able to do in central and southern CA. due to a lack of frequency availability. If people are from other parts of the country, are from the big urban areas of CA, they can't appreciate how complex building comm systems is there. Now I'm back in AZ, where I grew up. The terrain here is not as extreme and the state has 1/10th the population of CA. It is not very complex in comparison.
 
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Paysonscanner

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I just did a little research on recent FCC license grants in the region where late Hubby and I lived. Caltrans has been issued a license for 3 "roadside" located repeaters along CA Highway 88. We used to drive 88 in the winter as the closer passes were closed then. Heavy snow can fall on that highway and there is an avalanche problem near Kirkwood that is tricky, not to mention the avalanche paths on the east side of Carson Pass. They need good comms on that road. So 3 ground level repeaters are apparently needed to fill in coverage gaps. Keep in mind that Caltrans only needs coverage on the highways it maintains. Big gaps in coverage in areas without a state maintained highway exist, so the condition of their system does not represent what it takes to cover the entire state, including all those gaps. The CHP covers this highway from just two sites, Mt. Zion and Peddler Hill. They cover the east side from a repeater on the Grey from Leviathan. They need coverage in most of those gaps, so I wonder how well low band penetrates them.
 

mmckenna

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Leviathan should cover the east side of Carson Pass pretty well.
Peddler should do well on the West side. I can imagine some issues around Kirkwood, but maybe Peddler gets in there OK.

88 is our preferred east/west route since it avoids bay area/Sacramento traffic. 80 is usually a big mess with unprepared people and accidents.
50 is usually a mess with all the people going to Tahoe and the ski resorts. Last time I took 50, it took 18 hours to get to Carson City from the Monterey area. Usually 88 gets us across pretty quickly, even in the worst storms.

With 108 and 120 closed in the winter, there are not a lot of options.

In a jam once, I did go up to 70 and across. Feather River is mighty pretty in the winter.
 

scannerboy02

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Another thing to remember is with a P25 core you can do lots of linking between conventional/trunked, VHF/UHF/700/800 with little to no degradation in audio quality. They can also link analog low band to the P25 core for 'fill in' areas, with some audio quality loss. They are already doing this with the CHP Gold channel in Sacramento, the analog low band in linked to 700Mhz P25 conventional on Pine Hill.

I am a little surprised that CHP went with the Kenwood RF stacks instead of multi-band 'all in one' radios for this reason.
 

Paysonscanner

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Leviathan should cover the east side of Carson Pass pretty well.
Peddler should do well on the West side. I can imagine some issues around Kirkwood, but maybe Peddler gets in there OK.

88 is our preferred east/west route since it avoids bay area/Sacramento traffic. 80 is usually a big mess with unprepared people and accidents.
50 is usually a mess with all the people going to Tahoe and the ski resorts. Last time I took 50, it took 18 hours to get to Carson City from the Monterey area. Usually 88 gets us across pretty quickly, even in the worst storms.

With 108 and 120 closed in the winter, there are not a lot of options.

In a jam once, I did go up to 70 and across. Feather River is mighty pretty in the winter.
Apparently Peddler Hill isn't providing full coverage, otherwise they wouldn't have applied for licenses for 3 roadside repeaters. I just researched the use of roadside repeaters. Caltrans is linking them to the nearest microwave equipped site using 450-470 meg frequencies. The sites are then put on a voter system, so that the operator doesn't have to switch channels when it isn't clear which of the multiple repeaters is going to cover the spot. I did some searching on the Caltrans site and found some interesting info about their comm systems. I don't know if I could find the website links I used now.

Hubby always said, "if 88 isn't open, we are not going." He didn't like the potential circus of I-80 and didn't like U.S. 50 on any day of the year. The blind curves near the base of the Spooner Summit climb with people well over the speed limit really concerned him, thinking head on collision or having to put your car into the river to avoid one. Snow made the situation even worse. He liked 88 when the plows didn't keep up, he would rather drive in 6-10" of snow, than on the two alternatives when they are fully plowed. We skied Kirkwood often, mostly cross country, but occasionally went "yo-yo skiing" as well. Note: yo, yo skiing involves going up and down on a string (wire) all day. We were more "pinheads" than downhillers. We loved the Kirkwood downhill area, out of the way, not overly "Gucci" and often the best snow in the Sierra.

EDIT, sometimes our best bet was to go over CA4, Ebbetts Pass, depending on where on the eastside we were bound for. Now, in Arizona, I'm memorizing the "Beeline Highway."
 
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mmckenna

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Apparently Peddler Hill isn't providing full coverage, otherwise they wouldn't have applied for licenses for 3 roadside repeaters.
I was referring to VHF low, not 800. While I'm sure VHF low won't cover anything, it's probably still a decent site.

As for CalTrans and 800, I'm sure there is some logic to it, but I'd have loved to see them leverage low band, add more sites. Not an issue getting frequencies. I've got an 800 trunked system and an 800 conventional repeater at work, and It wouldn't be my choice for wide area communications.

Hubby always said, "if 88 isn't open, we are not going." He didn't like the potential circus of I-80 and didn't like U.S. 50 on any day of the year.
Yeah, some of what I've seen on 80 and 50 scares me. If some of it wasn't so reckless, it would be entertaining. Sort of like watching the antics at the launch ramp. Good cheap entertainment.

88 is pretty nice with a few inches of fresh snow. When the plows have cleared it, drivers tend to get a bit cocky. Drivers in their fancy Suv's with summer tires and all wheel drive forget that it won't help them stop. Or worse, some kid in a lifted truck with mud tires. Watched a kid with a brand new Toyota pickup truck, with no plates yet, plow into the rail trying to rush out of Kirkwood and get in front of me coming west on 88. Felt sort of bad for him, but he floored it in the snow and didn't realize he wouldn't be able to stop on the packed snow/ice.

EDIT, sometimes our best bet was to go over CA4, Ebbetts Pass, depending on where on the eastside we were bound for. Now, in Arizona, I'm memorizing the "Beeline Highway."
yeah 4 and 108 are my favorites. Some day I'm going to spend a few days camping up there.
 

Paysonscanner

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I was referring to VHF low, not 800. While I'm sure VHF low won't cover anything, it's probably still a decent site.

As for CalTrans and 800, I'm sure there is some logic to it, but I'd have loved to see them leverage low band, add more sites. Not an issue getting frequencies. I've got an 800 trunked system and an 800 conventional repeater at work, and It wouldn't be my choice for wide area communications.



Yeah, some of what I've seen on 80 and 50 scares me. If some of it wasn't so reckless, it would be entertaining. Sort of like watching the antics at the launch ramp. Good cheap entertainment.

88 is pretty nice with a few inches of fresh snow. When the plows have cleared it, drivers tend to get a bit cocky. Drivers in their fancy Suv's with summer tires and all wheel drive forget that it won't help them stop. Or worse, some kid in a lifted truck with mud tires. Watched a kid with a brand new Toyota pickup truck, with no plates yet, plow into the rail trying to rush out of Kirkwood and get in front of me coming west on 88. Felt sort of bad for him, but he floored it in the snow and didn't realize he wouldn't be able to stop on the packed snow/ice.



yeah 4 and 108 are my favorites. Some day I'm going to spend a few days camping up there.
I think you made an error in your second sentence. I think it should have read "While I'm sure VHF low won't cover everything, it's probably still a decent site." Caltrans had a low band system of remote base stations that communicated to the mobiles on simplex. They probably had a central processing system with a voter that tied a number of repeaters in together. The vehicle operator did not change channels to select certain peaks or talk simplex to other units. They would have greatly benefited with tone selected repeaters to extend car to car coverage and let everyone within range of a repeater to able to hear what mobiles were saying to their dispatch centers, Traffic Management Centers, etc. It is possible that they would not have needed any additional sites. Also they would be able to have both Caltrans and CHP in each and every radio. It would not be a panacea, as low band handhelds really stink.

The kind of entertainment value that I-80 and U.S. 50 can provide is lost since you have to be driving the road to witness the incidents. The Carson Spur near Kirkwood is challenging to drive, especially going eastbound (actually closer to southeast) downhill. Mr. Toad's Wild Ride is what Hubby called it. We had a close call there due to someone's complete lack of sense of awareness. One of those guys stopped in the middle of the road trying to figure out a chain problem with his head under the vehicle and his body waiting to be run over by anyone trying to get around him. Hubby had to pull some of the best snow driving he accomplished in his life not to kill man and needed the astute observations of an uphill (westbound) driver. It was such a difficult move to accomplish that when we reached the pull off to the downhill ski area he had to get out and vomit. This as a result of the huge dose of adrenaline his body produced in an instance.

In my late Hubby's notebooks there is a system diagram of the statewide CHP system. For 88 it shows Leviathan on the Grey, Peddler Hill and Mt. Zion on the White. I bet that on low band they have decent coverage, especially from Leviathan. Hubby and I loved standing on the walkways of the old lookout there with a map in front of us figuring out peaks, valleys, roads, etc. We would then take slides of the view, print them and label everything we figured out. The view from Leviathan is so incredible as far as how much "seen area" it has. Hubby and I loved working the 2m repeaters up there from the Toiyabe NF portion of the Carson-Iceberg Wilderness when we backpacked.

I think Caltrans has repeaters on all three of these sites, but that long ridge the road climbs toward the old ski area (Iron Mtn.) has a lot of curves, so they found that low band covers much more than 800 megs. This particular area proves the point that a statewide 700/800 system would be quite difficult in the Sierra Nevada, northern coast and Coastal Range of California. The stereotypical image of California is a large flat state, with Disneyland, beaches and freeways. There is so much more, but you have to experience it, visit the tiny towns (Downieville comes to mind) and stay in them for a couple of days. You have to climb the peaks, run the rivers, lock the hubs to drive the dirt roads, put a pack on your back, visit the great museums, the state parks, the national parks and all of the public lands to really know the state. Hubby had a great 3/4 ton Ford pickup with a camper shell on it when we got married, we wore that out on the long highway miles when we went on trips, so then we bought a Toyota Landcruiser for hiking and camping trips. The pickup was used to do the heavy dirty work on our property. I sold the Landcruiser, but kept the pickup. I don't have much use for it, but Hubby had purchased it just before his freshman year at Cal Poly-SLO where I first met him. That pickup is like an extension of him.

4 wheel drive = 4 wheel slide when trying to stop and on long downhill stretches.

Oops, I get off track, you see I don't leave the house much while caring for my parents. So I get pretty talkative at times.
 
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