CHP Vehicle Extenders

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rananthony04

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Are the new 700 MHz base extenders in full effect now ? Are people hearing extenders if they are close to stations? I never hear a peep near my station...
On 2 separate occasions recently, I was hearing repeated traffic on Baldwin Park's Orange extender(769.66875)-however, I was no where near the unit that was transmitting, but I was behind a new CHP unit and I was about a half mile from the BP CHP office. Just my 2 cents.
 

kearthfan101

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I thought you only have to be near a unit with their extender turned on… It doesn't have to be the unit transmitting. The extender allows the officer's portable radio to receive transmissions, and you were doing the same exact thing while monitoring on a scanner or radio.




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scottyhetzel

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I thought you only have to be near a unit with their extender turned on… It doesn't have to be the unit transmitting. The extender allows the officer's portable radio to receive transmissions, and you were doing the same exact thing while monitoring on a scanner or radio.

Yes near the vehicle extender or the base extender... Correct any transmission will be heard...in my area only the base frequency...L.A. has repeater on the the Mobile VHF low side. Yes exact same thing...however a 700 mhz signal. I much rather hear the 700 mhz side from my home than the scratch vhf low side.. I get tired of hearing the crummy sound of static and distortion.
 

SCPD

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I thought the officer had to enable the extender before the vehicle transmits on the 700 MHz frequency. I seem to remember viewing a video showing this. Is there a provision that prevents feedback when the officer transmits on the lowband mobile while the extender is on and transmiting the same signal over the 700 MHz extender's mike? It would seem that the officer would have to the extender off while in the vehicle.

Then again, this is a more complex system than the old 154.905 system. Turning the extender off and on would seem inconvenient. For example, the officer has the extender on while making contact with a driver. When the officer returns to the vehicle to run the license and uses the mobile, the extender would have to be turned off again.
 

rananthony04

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...the officer has the extender on while making contact with a driver. When the officer returns to the vehicle to run the license and uses the mobile, the extender would have to be turned off again.
This ^^ is what I presumed to be the purpose of the "mobile extender". Its been burned into our brains that the extender(old and 700 MHz) was only listenable within about a mile from the unit that has it activated. This is why I was surprised to hear the repeated traffic on the extender when I was no where near the unit that had it activated. That would mean the CHP unit I was behind had his extender activated still, I get it now. Was this possible with their old set up?
 

SCPD

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This ^^ is what I presumed to be the purpose of the "mobile extender". Its been burned into our brains that the extender(old and 700 MHz) was only listenable within about a mile from the unit that has it activated. This is why I was surprised to hear the repeated traffic on the extender when I was no where near the unit that had it activated. That would mean the CHP unit I was behind had his extender activated still, I get it now. Was this possible with their old set up?
Based on your observation it seems likely or at least possible that the 700 MHz extenders automatically prevent the feedback situation I described. You could then assume that if you hear the extender you are fairly close to a CHP vehicle. My experience in town at home, with a rooftop antenna (a mobile ham 2m/70cm) is the vehicle has to be no more than 0.3 miles from my antenna. This antenna is an issue and a discone is probably the way to go in order to receive them a mile or more away. Being able to receive the low band mobile and the 700 MHz extender from some distance is a challenge, a vexing endeavor.

I have no idea if the manual on/off was required when the 154.905 MHz extenders were being used. I remember reading in the initial CHPERS proposal that the new extenders can be control the mobile remotely, allowing the officer to switch channels. This includes operation of frequencies in any of the public safety bands. The problem with some extenders, such as those used by the county sheriff's department where I live, is the extender cannot control the mobile and the officers are stuck with whatever frequency is the mobile is on if they walk away from their vehicles. They use a 400 MHz extender and no one in the eastern Sierra use that band, with the exception of a few businesses. The extenders include the 400 MHz CLEMARS frequency, but no one else has it. If they want to switch to CLEMARS or other VHF-High tactical frequencies when they leave the mobile on their dispatch frequency they have to return to the unit and do it manually. This can compromise officer safety. Think of an officer arriving first on scene and being the initial incident commander, something that requires speaking to dispatch to report the conditions at the incident. Communication with dispatch is needed at that point, up until other officers arrive. The officer then needs to communicate on a tactical frequency and can't do so on the extender because it can't control the mobile. Not having the capability of switching to a tactical to communicate with the other agency officers arriving is what compromises their safety. As a deputy I know, a former co-worker of mine before he left the Forest Service, said "it will take an officer getting shot or physically assaulted to fix the problem." If ham handhelds can be dual or triple band and are capable of "extender" operation using a single band (i.e. 2m frequencies for both the handheld link and mobile transmit) why can't commercial grade handhelds and mobiles do the same thing?

If what I recall is correct the CHP 700 MHz extenders can switch from VHF-Low to communicate with dispatch, then be switched to a VHF-High frequency, such as CLEMARS or CALCORD, when the officer is away from the vehicle. In rural areas VHF-High is the preferred band and switching to it from the CHP low band frequencies is essential when working an interagency incident. This is quite frequent as many times a CHP officer is closer to an urgent situation, say a domestic violence incident or someone attempting suicide, than a deputy. They need to communicate with both the CHP and the S.O. dispatchers as well as on a tactical when the deputies arrive. With the 154.905 extenders the county S.O. dispatch channel and CLEMARS/CALCORD frequencies were programmed. This allowed direct communication on dispatch and tactical VHF-High frequencies.

If someone knows if the new CHP extenders have the ability to remotely control the mobiles I would like to know. The last time I spoke with a CHP officer I noticed the new handheld on his belt. He had been issued the new extender handheld the day before and had no idea of how it worked yet. The area office was not going to conduct training until all the other officers had the new extenders. He was told to only use the extender on the low band CHP dispatch and the car to car channels. He wasn't able to work on VHF High due to his lack of knowledge. He could not answer my question about the remote control of the mobile. He knew far less than I did about the new extenders because he had not read the CHPERS proposal or any other relevant material.
 
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This ^^ is what I presumed to be the purpose of the "mobile extender". Its been burned into our brains that the extender(old and 700 MHz) was only listenable within about a mile from the unit that has it activated. This is why I was surprised to hear the repeated traffic on the extender when I was no where near the unit that had it activated. That would mean the CHP unit I was behind had his extender activated still, I get it now. Was this possible with their old set up?
I notice that also they keep them on when moving or forget turn them off, but it's great for us.
 

SCPD

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I notice that also they keep them on when moving or forget turn them off, but it's great for us.
I recall the CHPERS proposal or outline stated that the new extenders would have a greater range than the old ones. I seem to remember that the limited range of the 154.905 extenders was an issue addressed in a CHPERS document. It does make receiving it from an extended distance using an antenna that can receive a decent signal on VHF-Low as well, a problem.
 

scottyhetzel

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There was a post that stated that the mobile extender activates when exiting the vehicle...like the dome light circuit triggers a relay.... The officer has to disable it while back in the driver seat.. In my area officers run the licenses / plates thru the mdt....unless they are in pursuit. Obviously motor units do not have this luxury.
 

K6CDO

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The 154 MHz extenders were activated by pushing a button on the control head; the radio in the car played an anoying beep out of the mobile radio speaker while the extender was active (as a deterrent from the officer leaving the extender on while in the car, in an effort to prevent multiple units from providing VRS services when more than one unit was at a given location).

I have not seen how the new 700 MHz extenders are configured.
 

scottyhetzel

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If you had the three officer out of their vehicles... They would all have their extenders on... If each one keyed the mic, It would hit their low band unit. I doubt if only one can be on. It would be too hard to keep everyone playing correctly.
 

kayn1n32008

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I know pyramid mobile repeaters, if all on the same frequency, have the ability to know when another extender comes with in range. When this happens the newest arriving repeater becomes the active repeater, and the first repeater on scene goes into standby. If a third shows up, it becomes the priority active repeater with the first two going into standby. The reverse happens when the repeaters start leaving scene.


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SCPD

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There was a post that stated that the mobile extender activates when exiting the vehicle...like the dome light circuit triggers a relay.... The officer has to disable it while back in the driver seat.. In my area officers run the licenses / plates thru the mdt....unless they are in pursuit. Obviously motor units do not have this luxury.
I don't know what the status of MDT operation for units assigned to the Bishop and Bridgeport Area Offices. All the black and whites I've seen in the last 6-8 years have computers installed in them. There are a lot of cell phone dead spots in the two county eastern Sierra region, so it is possible they only run plates/licenses in those spots. I hear them running information when making a stop between Big Pine and Bishop and I don't remember that being out of cell phone coverage. Things are usually different in rural areas and don't resemble metro procedures very much, if any.

I've lived in two towns in the region for 33 years. I've never seen a law enforcement motor unit of any agency in that time period. I bet I could count the number of times aerial speed enforcement operations have been conducted on two hands, at least within scanner range. They usually do it on Sundays in the winter when a lot of accidents occur, the result of some insane driving because people skied the morning, were hung over from their Saturday night experiences or did not get enough sleep the entire weekend. There are also high elevation effects, most of which develop when people don't drink enough non-caffeinated beverages. Combine that with excessive speed and their willingness to take significant risk to arrive or get home 20-30 minutes earlier than they would if they make dangerous passes in the last remaining two lane highway in southern Inyo County or set their cruise controls at the speed limit instead of 85-90 mph. When they travel at that speed they make bad lane changes and passes that endanger everyone in their vicinity. We generally don't drive anywhere south of us on Fridays or Sundays. If we have to we often see cars with roof mounted, full ski/snowboard racks being driven at significantly excessive speed. I usually say it at least once during the drive "Oh boy, look at me, I'm going to get to Mammoth and watch 20 minutes of MTV than you will!" How important are 20-30 minutes when compared to the risk these drivers pose to themselves, their passengers and everyone else they drive by? I know of two accidents where pot was a factor, one of them resulted in the death of a CHP officer. To accomplish getting home or to Mammoth Lakes usually involves speeding through towns have reduced speed limits, 55 in Olancha, 25 in Lone Pine and Independence, 35 in Big Pine and 30 in Lee Vining and Bridgeport. They call them "hick towns with sped traps." They are apparently unable to view the issue the way those of us in small towns on U.S. 395 do. They have never gotten out of their cars and tried to cross the highway at a pedestrian crossing or drive in town where entering, crossing or making left turns on 395 is involved.

I like seeing the CHP operating DUI checkpoints, maximum and aerial enforcement. The CHP does this and is available to respond to incidents where the county and sometimes cities don't have enough officers or have extended response times. They even come into Mammoth Code 3 when near riots occur in "The Village at Mammoth," an outdoor shopping mall with hotel condos above. Events and the bars there attract some morally challenged individuals. They participate on interagency teams for New Years or other large events and are sometimes half of those teams. They are no nonsense officers on the highways. Search and rescue operations often require a helicopter. Congress requires any use of USFS, BLM and NPS aircraft used on county incidents (S&R mostly) be reimbursed at the contract rates the agencies pay. The counties won't use the closest available helicopter the USFS has stationed in Independence. The CHP has helos with a paramedic on board and the counties don't have to pay for it. They work several S&R incidents each year and the counties depend on them.

I was listening to a two state pursuit when we camped at Furnace Creek in Death Valley NP. They were members of an extreme right wing organization, were heavily armed and shot at a Nye County deputy and NHP officer. They were blocked north of the Furnace Creek area so they took out on foot. They attempted to walk toward the campground. Several park rangers positioned themselves north of the campground and a few contacted everyone in the campground that an immediate evacuation might occur. The NPS Death Valley fixed wing patrol was launched and it was used to divert subjects away from Furnace Creek. The subjects fired at the plane, but didn't hit it. I don't remember if the observer returned fire. "They changed course and walked to the west toward the Panamint Mountains. CHP's Barstow helo responded and the subjects hunkered down in a spot where they had the cover of several large boulders. They shot and hit the CHP ship with a large caliber weapon. The ship immediately experienced oil and hydraulic leaks and had to land fairly close to the extremist's position. They were fired at after they landed, but were able to take cover behind the helo. A NPS SWAT team arrived and they gave up in the predawn hours. This started early on a Sunday morning and my wife had a job to return to. I tried to get her to get a ride home with our friends and let me stay to the end. It didn't work, darn it.

Rural areas with small isolated towns depend on the CHP much more than metro area local jurisdictions do. It would be hard to operate without them.
 
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jodystott

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The 154 MHz extenders were activated by pushing a button on the control head; the radio in the car played an anoying beep out of the mobile radio speaker while the extender was active (as a deterrent from the officer leaving the extender on while in the car, in an effort to prevent multiple units from providing VRS services when more than one unit was at a given location).

I have not seen how the new 700 MHz extenders are configured.
This was not the reason the beep or tone was used for. It was an officer safety issue/incident that took place the beeps were for.
 

mikewazowski

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Gentlemen, I've moved your vehicle extender discussion to it's own thread since the original purpose of the other thread was to discuss the new base extenders.
 

mlangeveld

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With the old 154.905 extenders, the officer had to hit a button to activate the extender when he got out of the car. The purpose of this was to establish priority between extenders at the scene, to prevent multiple extenders from conflicting with one another. As a result, it was very uncommon to hear a VHF extender in use while the officer was driving around.

With the new 700 MHz extenders, priority is established automatically during repeater idle time, without any need for user intervention. As a result, it is much more common to hear the new digital extenders in use while the patrol car is moving.
 

jodystott

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Please explain.... Your statement is not clear.
In the older vehicle when the repeater was activated inside the car the radio would beep every 2-3 seconds to let the officer know that the repeater was activated. Another person post that the beeps were so the officer would turn the repeater off when the officer got back into the car since the beeps were annoying to listen to. The reason that the beeps were add was because if by mistake you double pressed the button the repeater would have been turn on then off again.
 

K6CDO

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In the older vehicle when the repeater was activated inside the car the radio would beep every 2-3 seconds to let the officer know that the repeater was activated. Another person post that the beeps were so the officer would turn the repeater off when the officer got back into the car since the beeps were annoying to listen to. The reason that the beeps were add was because if by mistake you double pressed the button the repeater would have been turn on then off again.

Jody, thank you.

I was the original poster you cited as 'another poster.' My statement was based on a discussion with the CHP's Telecommunications Systems Manager who ordered the beep installed in the fleet, back when he and I were contemporaries at different state agencies, due to multiple occurrences of a unit in Southern Division at one edge of a given patrol area driving with the unit's extender on, and making a stop in range of another unit in the adjacent area (and on a different low band frequency) with that unit's extender on; one officer would key up both vehicle radios (on both of the channels), which would often interfere with traffic on the other unit's frequency. In at least one instance, the second unit's channel was carrying emergency traffic, which was disrupted by the (innocent) officer running a person on the proper (non-restricted) channel.

None the less, it sounds like implementing the beep cured a number of problem points.
 
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