CalFire Repeater Question

[brendan3]

Hey all,

I have been scanning calfire command and locals which I understand are “repeated” frequencies.

When a transmission is repeated is it only repeated through the tower that the transmitting radios tone is set? Or does it ever work like a simulcast system where repeaters in the area will work together to repeat the transmission?

 

[markclark]

Hey all,

I have been scanning calfire command and locals which I understand are “repeated” frequencies.

When a transmission is repeated is it only repeated through the tower that the transmitting radios tone is set? Or does it ever work like a simulcast system where repeaters in the area will work together to repeat the transmission?

I can tell you the Grass Valley Net uses multiple transmit sites simultaneously for nearly all transmissions on the main dispatch channel.

I can't speak to other Cal-Fire systems around the state. I'm sure other members will comment on their respective areas.

Good Luck!

 

[brendan3]

I can tell you the Grass Valley Net uses multiple transmit sites simultaneously for nearly all transmissions on the main dispatch channel.

I can't speak to other Cal-Fire systems around the state. I'm sure other members will comment on their respective areas.

Good Luck!

Thanks for that.

I’m in San Diego/Riverside area so wondering how those systems work.

 

[KK6ZTE]

Hey all,

I have been scanning calfire command and locals which I understand are “repeated” frequencies.

When a transmission is repeated is it only repeated through the tower that the transmitting radios tone is set? Or does it ever work like a simulcast system where repeaters in the area will work together to repeat the transmission?

Does it sound clear or is there a buzzing sound? No matter how good any simulcast system is, there will be spots where you hear two sites at equal strength and different times, causing simulcast noise. Or, like the junk USFS/LPF does where they key multiple tone select sites at once, all unsynchronized, and it sounds bad everywhere.

Typically, the "Local Net" and "CDF Command" State owned and operated systems are tone select and only the tone specified (ex. "Tone 2") site will repeat. However, some of the County owned and operated systems may be simulcast. For instance, CAL FIRE SLU/San Luis Obispo County Fire uses the simulcast County Fire Dispatch channel for dispatch state and county incidents, and they have three additional simulcast command channels available for use, in addition to SLU Local and CDF Command nets.

 

[Kingscup]

Riverside is not simulcast. Pretty sure neither is San Diego but not positive.

 

[mmckenna]

My -old- documentation on the CZU area shows that the dispatcher would reply on the specific repeater/tone for the unit that called. That may be out of date now, but it was true a few years ago.

 

[officer_415]

When a transmission is repeated is it only repeated through the tower that the transmitting radios tone is set?

This is typically how Cal Fire's local and command nets work throughout the state. You'll hear units calling dispatch and vice versa "on local tone 4" or "command 1, tone 1" etc.

 

[avdrummerboy]

BDU unit selects the individual site for dispatch and command/ response. They can open up all towers but such all call scenarios are infrequent.

 

[tkenny53]

Generally, output tone will be constant for the area, command and tach channels may be different.
Riverside will dispatch to many sites using tone/freq to a given tower, then the output is on a different freq and tone.,
So for like Indio, will be heard very distant in Temecula, as they are hitting the local tower in Indio for the area the call is going.
I have tried to use the input tone and freq to tower a few miles away, and it didnt help make things clearer. I can hear SD Co in Temecula very well.

 

[ECPD279]

Around the bay, SCU repeaters are unlinked and each have a different input tone, even though the input and output frequencies, and the output tone all match. The repeater that is being talked into is the only one repeating. Listen to the daily fire weather broadcast on the local, and if they repeat it three or four times, and start each one with something like "SCU fire weather forecast on local Tone 1..." you'll know your repeaters aren't linked. If they read it once, they're probably linked.

This will happen when they're toning out large incident dispatches too. You'll hear tones that might be strong, then a pause, and then tones that are scratchy or vice versa. They're sending the tones on the repeater that is closest to each station. Then they'll usually repeat the dispatch more than once, to hit each repeater.

 

[nokones]

CDF repeaters are controlled from the Command Centers for the area of their operational responsibilities. Some repeaters may be controlled by using mux circuits on the State's Public Safety Microwave or by using a specific CTCSS tone from a local or remote control station.

All repeaters receive a 159 Meg freq from the mobile and transmit out on a 151 Meg freq. Each repeater will decode a specific CTCSS tone that the mobile must select depending on the area they are in, and in some cases the Command Center.

The DWR (Department of Water Resources) and Fish and Game use the same 159/151 freq configuration for their repeaters.

The repeaters are not simulcast or multicast.

 

[mcjones2013]

Related fun fact, the LNU St Helena Command Center uses a remote transmitter in Sacramento (on a state tower near Downtown) to hit at least some of the LNU EAST (151.340) repeater sites.

If you use an altitude graph between the St Helena ECC and the LNU EAST repeater sites you can see the ECC is in a valley and doesn't have line-of-sight to most if not all the repeater sites, but the Sacramento remote transmitter does.

 

[nokones]

Related fun fact, the LNU St Helena Command Center uses a remote transmitter in Sacramento (on a state tower near Downtown) to hit at least some of the LNU EAST (151.340) repeater sites.

If you use an altitude graph between the St Helena ECC and the LNU EAST repeater sites you can see the ECC is in a valley and doesn't have line-of-sight to most if not all the repeater sites, but the Sacramento remote transmitter does.

If they are using a remote control station to control sites from St. Helena along that ridge line where Mt. Vaca sits, they may be trying to control stations like Berryessa, maybe St. John and other sites that are not on the microwave system. I don't recall if Berryessa and St. John are microwave controlled or not. By now maybe they are.

A control station at the Richards Blvd. would make sense if they are trying to control repeater sites along that ridge line from St. Helena. Of course, I would assume a remote control station controlled by St. Helena would also make sense if it was at Mt. Vaca unless it may be a frequency issue with the Bay Area.

 

[mcjones2013]

If they are using a remote control station to control sites from St. Helena along that ridge line where Mt. Vaca sits, they may be trying to control stations like Berryessa, maybe St. John and other sites that are not on the microwave system. I don't recall if Berryessa and St. John are microwave controlled or not. By now maybe they are.

A control station at the Richards Blvd. would make sense if they are trying to control repeater sites along that ridge line from St. Helena. Of course, I would assume a remote control station controlled by St. Helena would also make sense if it was at Mt. Vaca unless it may be a frequency issue with the Bay Area.

The tone I often see them using from the Sac transmitter is Tone 6 - 156.7, which according to the repeater map would be Mt St Helena.

 

[officer_415]

The tone I often see them using from the Sac transmitter is Tone 6 - 156.7, which according to the repeater map would be Mt St Helena.

Weird, I would think they would be able to hit that from the ECC. A transmitter in Sac would make more sense for Mt Vaca, Berryessa Peak, and Walker Ridge.

 

[nokones]

Mt. Vaca is microwave controlled so a remote-control station is not necessary unless Cal-Fire wanted to go the cheap route and not pay for the mux charges. That was CalTrans' and Cal-Fire' philosophy many decades ago but Cal-Fire will still have to pay the mux charges for the control station at Richards Blvd. from St. Helena. The mux fees were charged by the miles from point-to-point, I don't know how they charge for a mux channel today.

 

[ramal121]

St Helena just made the announcement that the microwave to region HQ in Santa Rosa is down. West units should use tone 10 or tone 14 for now. Not sure how that works over here. I know that tone 14 (Geyser Pk) has no microwave or remote connections.

 

[brushfire21]

The tone I often see them using from the Sac transmitter is Tone 6 - 156.7, which according to the repeater map would be Mt St Helena.

I know a little about this and a few people at St Helena ECC. Mt SH Tn6 is usually direct from the "Big Tree" antenna which is at the ECC. If you are seeing 156.7 from Sac then someone may have chosen the wrong antenna to transmit from which can happen I suspect. Usually Tn5 is from the Sac antenna and possibly Tn4 as well, though Big Tree may have a good enough reach to hit Berryessa Peak directly.

Someone else posed a question about microwave on Berryessa. Having been to the radio site several times working on another wireless system in the same room, yes there is state Microwave on the tower and it interconnects a few different mountain sites. As there are other state agency(s) at the site, one for sure is using the microwave system. However I never looked to deep into if there was a connection between LNU east and the microwave side but doubt it.

 

[officer_415]

Usually Tn5 is from the Sac antenna and possibly Tn4 as well

This makes more sense. What about Tone 3?

 

[mcjones2013]

I may have gotten the tone wrong, usually they were seen while driving. I'll try to sit for a bit and see what I can grab with the attenuation on near the tower next time I'm around it.

Here's a screen grab from a video CAL FIRE took at the LNU ECC. If I understand their console correctly, they have two choices for LNU E, one in Sac and I'm assuming the other at the ECC, and can select which tone from either to use. There's also a dedicated VACA, maybe directly via microwave?