Onslow

[BryanTheRed]

Could someone do some explaining for me? What I want to know is why I can hear the Sheriffs Dept through out the county. ie I live in Richlands I can hear a Deputy in Sneeds Ferry which is about 35 miles away as if he was outside my house. But our Vhf system for EMS is patched to the TRS and I can't hear my squad in Jacksonville 15 miles away only close if they are on vhf but I can hear all EMS in the county on the 800's ????

 

[drew6553]

ihear ya i always thought onslow jacksonville was a bit confusing if i could sit down with your radio and get things figured out i be we could get it figured out. but i'm here in brunswick

 

[BryanTheRed]

Yeah possibly could do that! Would be fun.

 

[fmon]

Tune the antenna. VHF conventional FM has greater range then 800 trunking. However, if your scanner antenna is tuned to 800, the range should be much better, but VHF range may suffer some.

 

[drew6553]

well what scanner you using cause i also have the scan cat lite however not laptop so i would be forced to carry my tower up there to work on it if ya wanted me to j/k

 

[BryanTheRed]

Hey Jeff do you have any insight to this? It just doesent make much since to me that I can hear the total VHF system anywhere in the county and cannot on the 800 TRS....

 

[Robbyboy]

Onslow 800

This is weird, maybe you have a programming problem because I hear the Onslow 800 TRS as far out as Beulaville guaranteed and as far as wilmington at times...

Cheers

 

[BryanTheRed]

Its not that I just wonder why the Sheriffs Dept is strictly VHF and I can hear ALL of the deputies regardless of where in the county they are. And the county praises this 800 system that IMO sucks. I cannot hear all of the transmission to dispatch I even have this problem on the 2 way radios in Jacksonville which is much closer than where I live. I also can pick up the fire net most of the depts. But for instance I can hear all of Jacksonville Rescue transmission in Jacksonville but not in Richlands or anywhere else in the county but I can hear any EMS unit in the county same goes for Sneeds Ferry I simply cannot hear them but a deputy can be in their parking lot and I can hear him like I was in the car with him!!!! Any insight?

 

[BryanTheRed]

This is weird, maybe you have a programming problem because I hear the Onslow 800 TRS as far out as Beulaville guaranteed and as far as wilmington at times...

Cheers

I guess what I am asking is can you only hear the EMS units or can you hear all of the volunteer rescue squads in the county too?

 

[Robbyboy]

Onslow 800

Contrary to popular belief, they do NOT simulcast on Onslow 800. Ive been to the dispatch center AND in the field... They dispatch on Rescuenet. Events channels are generally cross patched, BUT they usually use 800 and the handful of rescue squads w/o 800 use tac8 etc.

 

[BryanTheRed]

So then whats the explination for why I can hear ALL sheriffs communications all over the county and only limited rescue personel?

 

[drew6553]

could it be prehaps that sheriff's is repeaterd and rescue is simplex? that's the only thing i can think of

 

[CCHLLM]

Don't know if they're using site steering, but if so, the only site that repeats incoming traffic is the site that was selected by the comparator. So if you're on the opposite side of the county from the unit talking, the signal from that site will be weak, if readable at all. What happens then is that when the unit being called replies, and if it comes from a different site, then both those sites are involved in the repeat function but can be on different channels. In that case, your scanner should hear at least one of the repeaters. The question then is, how would a unit on this side of the county hear one on the other side calling them initially? All trunking formats are capable of site steering on a per channel basis, but I don't know of any that do this unless that function is specifically selected by the comm center for special purposes (covert operations in a limited area, etc), and only if they have that capability specifically programmed into the control matrices and available to the consoles. I don't know of any systems doing this as a default.

When in the Onslow area, I've noticed that some 800 talkgroups are not nearly as strong as others, and seem to be "steered," but as to the system logic being used, ya got me.

 

[BryanTheRed]

I was wondering also if it had to do with the equipment. I know for a fact that all of the patrol cars have the same exact radios in them. And I know for a fact that all of the rescue radios are completely different, I dont however know if this would make a difference I would think a system on a channel with the same input and output watts would be better than the mismatched Rescue system!!!

 

[Robbyboy]

I know for a fact that Sheriff Primary is on a repeater system. I do not know how Rescuenet does it because I have never been able to find their input frequency, same for firenet.

 

[BryanTheRed]

You mean the input freq in the radios? I have a master template from the county as to what the freqs are in the VHF radios on the ambulances! If that would help ya??

 

[BryanTheRed]

Problem solved......The Rescue freq isnt repeated, its simplex....sucks!

 

[drew6553]

sounds like your going to need a

Big
Freaking
Antenna

pointed at the source. well good luck trying to figure it out

 

[BryanTheRed]

I've about said screw it! to me its not worht the time, money or hassle. My minitor allows me to hear pages away from work, all I have to do is turn on my HT-1000 or run up to the scanner and I can hear the call and what trucks are in route by dispatch answering them so oh well! LOL

 

[whitehelmet1202]

OK...here is what I have on how the system operates in Onslow County.

VHF EMS Dispatch is 155.400. This is mostly used by the volunteer rescue squads in the county. SOme have 800 radios, but mostly only the County Paramedic EMS units have the 800 stuff for EMS.

EMS is dispatched on a conventional ASTRO 800 MHz repeater. This is cross patched witht he 155.400 channel. When an EMS units talks on the 800 repeater, you hear what is being said on 155.400. The opposite is true as well. If you talk on 155.400 you will hear it on the 800 repeater. This is more like what hams call a "cross band" repeat, or cross patch.

The only way you would hear an EMS unit that is acutally talking on 155.400 is if you are close enough with your VHF radio to hear him . The same goes for the 800 channel.

The Sheriff's Dept uses a conventional VHF repeater on 155.565. ALl field units transmit on 158.970 and the repeaters output is 155.565. "418" uses the repeater as a base station, with only the field units actually using the full repeater.

I agree that simplex is a pain in the butt.

Ask some of the older emergency services members in Onslow what the communications used to be like. I started my fire service career in Onslow County 13 years ago. I remember when every VFD and VRS in the county had to have a "tone repeater" to transmit their pager tones from their base station so the volunteers' pagers would even activate.

I like the idea that they have for the cross patch between the VHF EMS channel and the 800 channel, bur both sides of the system need some work. I think the county was threatning to turn off the VHF for EMS altogether and force the VRSs in the county to go 800 Astro. The main problem with this is the price of the equipment that the VRSs will have to buy to completely switch over. Another problem is paging the volunteers. It's much easier to carry a Minitor pager than it is an XTS2500.

Not to mention the tight budget conditions of volunteer agencies in Onslow. I know the VFDs were facing at least a 3000.00 budget cut with more possibly on the way.

Just my $0.02

Jeff
Surf City, NC
SCVFD & SFVFD