Santa Cruz County

[Ghost117]

Santa Cruz County Sheriff and Fire have multiple sites with the same frequencies attached to their license in the DB, is that a voting system that they use?

Also, is there a benefit or reason for using CSQ? Wouldn't it be better to just use a PL or DPL, so there's no risk of interference from another county?

 

[mmckenna]

Santa Cruz County Sheriff and Fire have multiple sites with the same frequencies attached to their license in the DB, is that a voting system that they use?

Simulcast on the TX side for some channels.
They also use receiver site voting.

Also, is there a benefit or reason for using CSQ? Wouldn't it be better to just use a PL or DPL, so there's no risk of interference from another county?

"better" means a lot of different things. Yeah, it's good to use, but interference isn't a big issue here. I think as time goes on you'll see PL or DPL added to most.

 

[Ghost117]

When you say simulcast on the TX side, does that mean multiple sites transmitting on the same frequency? If so, wouldn't that cause heterodynes if two stations are transmitting on the same frequency?

 

[SteveSimpkin]

When you say simulcast on the TX side, does that mean multiple sites transmitting on the same frequency? If so, wouldn't that cause heterodynes if two stations are transmitting on the same frequency?

Yes, there often is some hetrodyning heard on analog Simulcast systems, depending on your location relative to multiple towers and how well the transmitters are aligned. Analog Simulcast systems require careful alignment to keep it to a minimum. The frequency of each transmitter is kept as close as possible to the exact same frequency. The phase of the analog audio fed to each each transmitter is also adjusted to keep it in phase at each site. All of this greatly reduces the hetrodyning and distortion heard by field unit radios.

 

[Ghost117]

Yes, there often is some hetrodyning heard on analog Simulcast systems, depending on your location relative to multiple towers and how well the transmitters are aligned. Analog Simulcast systems require careful alignment to keep it to a minimum. The frequency of each transmitter is kept as close as possible to the exact same frequency. The phase of the analog audio fed to each each transmitter is also adjusted to keep it in phase at each site. All of this greatly reduces the hetrodyning and distortion heard by field unit radios.

Yes, there often is some hetrodyning heard on analog Simulcast systems, depending on your location relative to multiple towers and how well the transmitters are aligned. Analog Simulcast systems require careful alignment to keep it to a minimum. The frequency of each transmitter is kept as close as possible to the exact same frequency. The phase of the analog audio fed to each each transmitter is also adjusted to keep it in phase at each site. All of this greatly reduces the hetrodyning and distortion heard by field unit radios.

I see, thanks for the info!

 

[mmckenna]

Exactly.
And they had that issue on Fire Red for a while. I believe it was partially caused by a transmitter located over on Toro above Monterey.
The transmitters are referenced to a GPS oscillator, so they stay on frequency very well. Timing is a challenge, but good techs (and they have them) can work that out.

 

[flux4201]

Also, is there a benefit or reason for using CSQ? Wouldn't it be better to just use a PL or DPL, so there's no risk of interference from another county?

Most older simulcast systems ran no PL on transmit as it was harder to phase the PL between all the sites, a lot of systems chose to not run PL unless you spent the $$$ to run PL. CSQ works great until co-channel happens.

 

[Stealthguy05]

Any idea what system they are running? Tait QS2? It sounds similar to the old Hayward channels that used to use the Tait solution. A bit too tinny sounding for my taste.

 

[mmckenna]

Any idea what system they are running? Tait QS2? It sounds similar to the old Hayward channels that used to use the Tait solution. A bit too tinny sounding for my taste.

Might be, but I'm not 100% sure what they are using at the TX sites. They have Tait TB8100 with RX modules at a few of my sites.

 

[Stealthguy05]

Might be, but I'm not 100% sure what they are using at the TX sites. They have Tait TB8100 with RX modules at a few of my sites.

I'm impressed with my ear detecting that it was Tait voting sites. I'll have to ask around.

 

[ea1321]

Hi There,
Do you know if Santa Cruz County is going P25 Phase I or Phase II? I know the County S/O has deployed all new APX radios to their units. I was just curious if they are getting ready to switch to a knew system like Santa Clara County has done. Usually when they hand out new radios, that is a sign that something is in the works.

Thanks!