Pyramid vehicular repeater.

[dixie729]

Not really sure where this topic belongs. Admin, feel free to move this where it belongs.

Looking at getting one or a few vehicular repeater(s). Only need it for one channel so I was leaning on the SVR200.
We have a terrible time with portable radios transmitting to our dispatch on our repeater. An idea arose to look at maybe trying a vehicular repeater to make it better.
We are on vhf 137-174 band split.
Using CDM 1550 mobile radios in the trucks.
Are these VR units any good?
What is everyone's experience with them?

Kevin

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[iamhere300]

Not really sure where this topic belongs. Admin, feel free to move this where it belongs.

Looking at getting one or a few vehicular repeater(s). Only need it for one channel so I was leaning on the SVR200.
We have a terrible time with portable radios transmitting to our dispatch on our repeater. An idea arose to look at maybe trying a vehicular repeater to make it better.
We are on vhf 137-174 band split.
Using CDM 1550 mobile radios in the trucks.
Are these VR units any good?
What is everyone's experience with them?

Kevin

Sent from my XT1097 using Tapatalk

They work very well, if properly installed. Using a service monitor. Or two. Getting the levels correct is a must. Of course, you might be able to throw it together, but it will never be right.

 

[dixie729]

Let's say I put one in 3 trucks. And all 3 of those trucks are on scene. Now, we could have 5 or 6 people on portable radios hitting these VR's and at sometimes have 3 other departments keying up portables.
-Could this be a problem?
-Do the VR's stay on all the time?
-How far away can you be away from the VR before it's not going to work?


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[mmckenna]

You need to decide how you are going to do it.
There are two options:
In-band, where you are using the same band from the portable to the repeater as the mobile radio is using.
Out of band, where you are using a different band than the mobile.

If you use them in-band, then you -must- get a VHF frequency that is as far away from your dispatch channel as you can get it. There are 5 173MHz channels, I believe, that were set aside for this. That separation from the 15x.xxx frequencies helps reduce the chances of desensing the repeater. You also are going to need proper filtering between the repeater and it's antennas to notch out the frequencies your mobile is transmitting on.
Failing to do this will result in very poor performance or interference that can mess up your dispatch channel.

It's a -really- good idea to get them installed and tuned by someone who really knows what they are doing.

Out of band is a bit easier. If your primary dispatch is on VHF, then using a UHF repeater solves some issues. But then you'd need to have UHF or dual band portables for everyone needing to use the repeater. Not always possible on small budgets.

The repeaters are designed to negotiate which one is "on" when there are multiple units at scene. This appears to work pretty well.

You can set up the repeaters to stay on all the time, have a switch in the cab that turns them on/off as needed, or hook them up to ignition switched power.

As for how far they will work, that depends entirely on antenna, topology, install, how well they've been set up, filtering, not to mention the variables with the portable radios.
You shouldn't have any issues getting 1/4 to 1/2 a mile. Maybe more, maybe less. If that becomes an issue, then you have some deficiencies with your overall radio system that likely need to be addressed.

 

[dixie729]

Thanks for the break down mmckenna. Our local Motorola shop will be doing all the setup of the units.
Just wanted to get some opinions and how it will all work.
You wouldn't happen to have a ball park price a one of the units would you ?

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[ramal121]

Funny this pops up as I just installed a SVR200 today. Logging company uses low band for their company radio. Since low band portables are becoming rarer and basically suck in performance, they elected to get a VHF SVR200 in a supervisors truck. Now with VHF portables they have the nut to transmit from a site with a 100 watt mobile.

As far a range I don't know as they need to try it out for a while, But I'd be comfortable to say at least several hundred yards to a quarter mile or so in thick California coastal forest, probably more. Unit is running 1 watt with a quarter wave antenna on the roof of a F-250.

The SVR200 is interfaced with a Kenwood TK-690 and can be turned off and on via an aux I/O button on the control head. Any switch can be used for this if needed however.

As mentioned, Pyramid utilizes a scheme where if multiple mobiles with repeaters are on site locally and switched on, one will take priority for repeat and the others will disable their repeat and standby waiting for a change in the situation. As long as you understand how this is accomplished the system works pretty well.

Let's say I put one in 3 trucks. And all 3 of those trucks are on scene. Now, we could have 5 or 6 people on portable radios hitting these VR's and at sometimes have 3 other departments keying up portables.

Not sure what you.re asking here but as I said only one SVR200 will be active at once and all portables on that channel will be repeated.

Now if there are two repeaters on different channels for the portables at scene and some portables work through one repeater and other portables work through another, well that is doable also. The mobile radios can even be on the same channel or different. Not a problem.

Again this is a cross-band repeater which is much simpler to configure than an in-band repeater where you have to consider the portable frequency as compared to any of the mobile frequencies you will use plus the filtering that is required to make it all work as mckenna has mentioned.

As far as cost, I normally don't get in on that end but with at least 3 hours of drive time-install-program-alignment-test, I would guess this would go north of $2K a tad.

 

[TampaTyron]

I am working on a similar solution for a open pit mining company. The company has a bunch of MOTOTRBO sites and has great coverage. However, there are a handful of locations where topology prevents getting signal into small pump type areas. BDAs are a no go. So customer has installed mobiles on power supplies inside NEMA boxes with the antenna on a 50-100ft mast with instructions to use this radio if you need help. Well, the safety schmucks are not OK with that solution. My fix is in-band UHF SVR on a simplex freq in the 450.xxx because the the MOTOTRBO system is trunking and operates in 451-454 and 460-464 repeater outputs. So, 450.xxx reject filter on mobile radio (set to very low power) AND a 450.xxx pass filter on SVR antenna. Set everything to as low of power out as you can to help filtering work better. TT

 

[RFI-EMI-GUY]

Not really sure where this topic belongs. Admin, feel free to move this where it belongs.

Looking at getting one or a few vehicular repeater(s). Only need it for one channel so I was leaning on the SVR200.
We have a terrible time with portable radios transmitting to our dispatch on our repeater. An idea arose to look at maybe trying a vehicular repeater to make it better.
We are on vhf 137-174 band split.
Using CDM 1550 mobile radios in the trucks.
Are these VR units any good?
What is everyone's experience with them?

Kevin

Sent from my XT1097 using Tapatalk

1) I would not ignore the option of installing a voted system to improve your portable talk back. JPS now offers an option with their SNV-12 voter to better utilize internet / IP back haul. Where your agency has a WAN connection you can install a satellite receiver. No phone line leases, no microwave required. The new JPS option is better integrated in the past. Please look into the cost if doing this before committing to vehicle repeaters. A big question is the size of the fleet as well as where you need coverage and where you might place a satellite receiver. A voting system is the best solution.

2) While you can do what you want with a Pyramid SVR200, unless you have dual band portables, the vehicular repeater will be "In Band" meaning that RF notch filters will be required in each mobile to allow for the duplex operation of the repeater. It can be done, and new frequencies were allocated near the top of the VHF band to accommodate this, but it will require some attention to detail and potential compromises.

3) The Pyramid SVR200 is a fine product, Pyramid has focused on a niche that they serve well and there should be application notes on their website to work with your radios. The priority technology used in the SVR200 was developed by Motorola, is proven and worked well 40 years ago.

4) An SVR needs to be activated when on scene. This can be done in a number of ways. Some agencies use a manual switch, but if the officer bails out and forgets, the repeater will not be activated. This means he will not be able to transmit through the repeater, nor hear dispatch.

A better solution is to wire a switch that activates the repeater when the vehicle is placed in PARK. The radio will also need to be powered on when the vehicle engine is off so it is assumed that a battery protection run/shutoff timer is installed.

5) Whenever a SVR200 arrives on the scene and is activated, it transmits a specific audio tone that is recognized by all other SVR's in range. This tone tells the other SVR's who is "boss", and that most recent SVR is the only one that will repeat. The other SVR's will wait some random 10's of milliseconds and if the "Boss" does not transmit, during the first few milliseconds, one of the other repeaters will take priority and become the "Boss".

6) There is a priority interrupt timer so that a portable can transmit back to the repeater during the repeater drop out delay. This causes a clicking on the VRS signal toward the portable. It is a necessary feature. It also means that a few milliseconds of audio might be missed waiting for the priority interrupt interval. (A training issue)

7) The portable radios receiver and the VRS transmitter must operate in the carrier squelch mode for the system to work with multiple VRS on scene. So some interference might be heard on the portable.

In my opinion, it is a workable solution, but has some quirkiness that may make it annoying under stressful communications. If your department is 15 officers and 5 vehicles and the officers are "techies" who can operate a cable TV remote control without getting frustrated, it will work. They do need to fully understand the operation and limitations of the system. If they are not so forgiving of quirky tech (untrainable), then satellite voting receivers might be a better solution.

One of my first assignments as a tech rep was to explain to a rural county sheriff in Iowa how the Motorola vehicular repeaters operated. His response to me was "I don't want to know how it works, I just want it to work". His department was not a good match for that solution.

 

[mdulrich]

4) An SVR needs to be activated when on scene. This can be done in a number of ways. Some agencies use a manual switch, but if the officer bails out and forgets, the repeater will not be activated. This means he will not be able to transmit through the repeater, nor hear dispatch.

A better solution is to wire a switch that activates the repeater when the vehicle is placed in PARK. The radio will also need to be powered on when the vehicle engine is off so it is assumed that a battery protection run/shutoff timer is installed.

Another good solution is a switch wired to activate the repeater when a front door is opened.

Mike

 

[sfd119]

Another good solution is a switch wired to activate the repeater when a front door is opened.

Mike

That...wouldn't work. Door opening would activate the repeater but shutting it would shut off the repeater. Not to mention how many times an officer will go back into their squad during a traffic stop or other event.

 

[clbsquared]

That...wouldn't work. Door opening would activate the repeater but shutting it would shut off the repeater. Not to mention how many times an officer will go back into their squad during a traffic stop or other event.

There is a way to do this using a relay and a momentary switch. You would need to jump pins 87 and 85 on the relay so that when 85 is energized and activates the relay, 87 then keeps 85 activated after the momentary switch has reset itself. To reset the relay, you would then need to either break 86 (ground) or 30 (power supply) with another mechanism.

 

[RFI-EMI-GUY]

There is a way to do this using a relay and a momentary switch. You would need to jump pins 87 and 85 on the relay so that when 85 is energized and activates the relay, 87 then keeps 85 activated after the momentary switch has reset itself. To reset the relay, you would then need to either break 86 (ground) or 30 (power supply) with another mechanism.

Way too complicated. And what mechanism resets this? Just use the park switch circuit and be done with it.

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[clbsquared]

Way too complicated. And what mechanism resets this? Just use the park switch circuit and be done with it.

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I agree, it's complicated. But it was said that wiring the VRS to the door switch wouldn't work though. If a relay was used, it could work. As far as resetting it, a simple toggle switch could perform that function. Or you could get creative and find another way. Maybe the brake pedal, or seatbelt switch. But the Park Kill is in fact the easiest way to do it.

 

[Project25_MASTR]

One might look into the X10DR speaker mics. TxDOT tried a few out on their trucks and were able to get 1000+ ft away from their trucks using an external 2.4 GHz antenna. Also it's a full duplex link so it'll work for trunking.

Other than that, I'm with others in the opinion that a multi-site or voted receive setup should be looked at and is often much more cost effective compared to outfitting a bunch of vehicles with VRS setups in in-band applications.

 

[12dbsinad]

If you're debating a in band VRS, expect to dish out some money for it to work correctly. In all my years, I have seen VERY few in band systems without desense, sometimes severe. I have seen Motorola shops throw these things in and have the end user very disappointed at the performance. It usually takes lots of testing on each vehicle to make it work. Antenna placement, notch filters, etc needs to be engineered on every vehicle. Out of band VRS are way more forgiving. But you'll either need dual band portables, or dedicated portables in the vehicles to use on the VRS.

Try looking at the X10DR as was stated, made by wireless pacific. I have used these with good results for the fraction of the cost of a vehicle repeater.

 

[sfd119]

One might look into the X10DR speaker mics. TxDOT tried a few out on their trucks and were able to get 1000+ ft away from their trucks using an external 2.4 GHz antenna. Also it's a full duplex link so it'll work for trunking.

Other than that, I'm with others in the opinion that a multi-site or voted receive setup should be looked at and is often much more cost effective compared to outfitting a bunch of vehicles with VRS setups in in-band applications.

I'd stay away from the X10DR mics right now. You can get GREAT range out of them while you're outside. Going inside a building...not so much.

 

[Project25_MASTR]

I'd stay away from the X10DR mics right now. You can get GREAT range out of them while you're outside. Going inside a building...not so much.

That's because it's essentially bluetooth and is 2.4 GHz (I did mention that it was 2.4 GHz in my original suggestion, as well that it is a full duplex link unlike a VRS setup).

The main thing being, if it's going to cost between $2,000 and $2,500 to do a proper (assuming in-band) VRS setup per vehicle and 10 or so vehicles are going to be equipped...you are in the price range of upgrading your infrastructure to voted receive and depending on the manufacturer, that's all new infrastructure.

 

[mdulrich]

There is a way to do this using a relay and a momentary switch. You would need to jump pins 87 and 85 on the relay so that when 85 is energized and activates the relay, 87 then keeps 85 activated after the momentary switch has reset itself. To reset the relay, you would then need to either break 86 (ground) or 30 (power supply) with another mechanism.

Not sure of the wiring that was done, but that is how I've seen some systems setup. A momentary switch would shut it down. This allows a partner to get out on foot activating the repeater while the car can still be driven in the area.

Mike

 

[KC4YDY]

I think you guys are overthinking this a bit... The TV station I work for has the Mototurbo radios in our vehicles (30+ radios) and about half of them have the Mototurbo handhelds. We use a drop-in charger that has a simple microswitched wire that ties to the SVR. Walkie is in the charger, no SVR. Pull out the walkie, SVR comes on.

If you are using in-car drop-in chargers, check their install diagram to see if it doesn't have some switched lead that triggers an in-charger/out of-charger signal. Your radio installer should easily be able to wire it up.

My personal vehicle has a HAM dual-band, Mototurbo, SVR, walkie w/drop-in charger, CB, and a scanner. I can almost get my legs under the dash! LOL

 

[nozzle75]

@Dixie729, my Department uses the Pyramid SVR200 repeaters and against my recommendation, they went in-band WITHOUT the pre-selectors (filters). The first page of the SVR-200 manual discourages the use of in-band operation. Our FF's can go about 20' from the truck without the mobile desensing the repeater and wiping it completely out. I installed pre-selectors in the front line Engines and now we get about 200 yards of coverage from the portable to the Pyramid repeater. I installed a UHF repeater in the Battalion Chief's vehicle and provided them with a UHF portable (only use this radio if you need to use the vehicle repeater) and they get 1/2 mile or better coverage. If you're on VHF, use a VTAC channel for fire ground and buy some cheap UHF portables for IC radios. Your IC will have to carry both radios, but it works out really great for us. Oh, and like mmckenna said, take advantage of the 173.xxx channels if you choose to stay in band AND buy the pre-selectors tuned for the frequency you will use.