CHP Oceanside

[nhse]

The Oceanside and San Diego channels just don't perform as well as when they were on 42mhz vs 39 MHz. It's great that they are repeated but the power is much lower and because they are simulcasting on several sites at once cause lots of dead spots. I can move line of site just a few hundred feet and go from full quieting to almost unreadable. Many tines you will hear the field units telling dispatch they are unreadable. Last year they did lots of testing and tried different fixes but I think they have given up. Of course there is a spot on god RCS for them but I haven't heard of any plans to switch. I have tried different antenna configurations but seems to only amplify the noise in my area because of the simulcatt.
Anyone hear of any new fixes?

 

[Anderegg]

The CHP in SD is not simulcast. You will hear the signal change dramatically as the dispatcher selects a different mountain, or when the repeaters vote, if they still do voting.

It is not uncommon for a CHP vehicle to be parked just right on a freeway in a ok coverage area, to not hit the repeater unless they move their patrol car a foot or so!

Paul

 

[nhse]

Simulcast was the wrong word. As I understand the new system, they rebroadcast on several mountain tops at he same time and the multi path is problematic over much of our areas. For weeks last year they tried to tweek the timing but never got it to work well at all. Some areas are great, a few hundred feet over and the multi path cancels out the other signal since the timing is off. I know during pursuit that they have turned off one or more of the mountain tops for officer safety. I can be on a mountain top looking at all the sites and have a great signal and move a few hundred feet and crap.

 

[K6CDO]

Simulcast was the wrong word. As I understand the new system, they rebroadcast on several mountain tops at he same time and the multi path is problematic over much of our areas. For weeks last year they tried to tweek the timing but never got it to work well at all. Some areas are great, a few hundred feet over and the multi path cancels out the other signal since the timing is off. I know during pursuit that they have turned off one or more of the mountain tops for officer safety. I can be on a mountain top looking at all the sites and have a great signal and move a few hundred feet and crap.

Actually, Simulcast is the correct word - broadcasting the same audio signal on the same frequency from multiple transmitters at the same time. The issue is that the wavelength at low band is so long that getting everything compensated for properly is very difficult, hence the multi-path issues. Oceanside and Temecula are Simulcast. I don't know about San Diego.

 

[Anderegg]

Don, what is the correct word to describe the analog crackling/warbling/popping on simulcast 800MHz signals? I know there must be a specific technical word for it.

Paul

 

[K6CDO]

Don, what is the correct word to describe the analog crackling/warbling/popping on simulcast 800MHz signals? I know there must be a specific technical word for it.

Paul

I've never seen a technically correct term for it. We call it "grunge."
It's the analog equivalent to the 'R2D2' digital effects of multi-path, and can be caused by almost anything - including that semi next to you in traffic or on the road behind your house.

Don

 

[kma371]

OPs question was answered long ago. if you guys have some sort of personal issue, contact each other directly.