Can't hear Dispatch....questions on that.

[muskytooth]

I am new to scanning.......less than a week. I am able to hear the local sheriff talk to dispatch but I can't hear dispatch....

So the questions are as follows....

1. I see the input to the repeater freq. listed on this sight. Should I be using that or strictly the output frequency?

2. Because I can't hear dispatch does that mean they are trunking?

3. Is it possible that I don't have the correct type of system selected? ie conventional vs motorola etc.

4. Is it a combination of the above?

Uniden BR330T

 

[rpowley]

What state, county, and system are you monitoring?

 

[ECHO3]

In general you would program only the repeater out frequency. Sometimes this frequency is also listed as the repeater transmitting frequency. This would apply to conventional frequencies only, e.g. 164.5875. Trunked systems have different requirements.

 

[muskytooth]

Polk County WI, Sheriff on 155.550.

That brings up another question. How can you tell if it is a conventional system or a motorola system etc? Just by the numbers used?

 

[rpowley]

Polk County WI, Sheriff on 155.550.



That brings up another question. How can you tell if it is a conventional system or a motorola system etc? Just by the numbers used?

As ECHO3 states, normally you will use the output frequencies (shaded in green in the RR Database) Most frequency databases will show if frequencies for a specific agency or system are conventional or trunked. If you are missing complete communication on a frequency it might help to increase your delay.

 

[KC4ZEX]

If it is on 155. or any high band ch its standard simplex or a repeater in analog. you only need the output freq. Same for low band and a lot of the uhf 450. On 450 you get into some digital. This is where you get into the motorola p25. GE edacs and a few other systems and on 800 mostly trunked and some systems you can't listen to.

 

[BoxAlarm187]

Just to clarify, 95% of the time, frequencies in the 155Mhz range ARE analog, non-trunked, but trunked VHF (and UHF) systems DO exist.

 

[kb9tyc]

Polk County is almost complete if not complete with a communications system upgrade so that may have something to do with it.

If you look up the callsign for the following record on the FCC website it has the Sheriff' Departments address and phone number. The Cumberland record is a new tower that was just put up.

http://www.radioreference.com/modules.php?name=RR&action=fcc&cs=WQFB539

 

[ECHO3]

Trunked systems are identified on the site's database. VHF high band is not trunked. In response to your initial question, I was using "simplex" as my example. That means both the dispatcher and units are on the same frequency. If you program the repeater out frequency, on such a system, you will hear both sides of the com, unless distance is an issue. On a "duplex" system, such as the current PSP system, the base receives on one frequency and the units on another.

 

[JoeyC]

Trunked systems CAN be on the VHF high band, just as conventional stations CAN be in 800 mHz.
Digital modulation CAN be on VHF high band.
Polk Co WI SO shows to be on conventional freqs in the DB.

 

[kb2vxa]

...- ...- ...- We interrupt this off topic technical debate for a breaking story.

The answer is most likely it's simplex (a bit old fashioned but Podunk Iowa might still use it) or a repeater. Considering the frequency it's probably Podunk, older simplex assignments tend to become repeater outputs with inputs in the 159 range. The clincher is looking up the agency, note it's frequency assignments and search for the correct one(s). Once you have all the assignments you have eliminated the guesswork and can sort them out.

You guys would be lost without the FCC database and web sites like this, before the Police Call book we had to do it all ourselves and there was no such thing as a scanner either. Sounds like one of granddaddy's "when I was your age" stories? Well, it IS! (;->)

This has been a special announcement from KB2VXA Geezer Wireless News, we now return you to the technical misinformation exchange already in progress. ...- ...- ...-

 

[nexus]

Well according to the DB its a repeater, and 155.5500 is the output and 158.8500 is the input. But there are two other sheriff frequencies, one is labeled car-car and the other just says its sheriff, but those are obviously simplex since there is no input.

if he's hearing units on 155.5500 then he should be able to hear dispatch as well.

Musky, you certainly want to be using the output. The input is useful if you're within a couple miles of the unit but that's all. Everyone should be listening on the output. Are you using any PL tones? If so perhaps dispatch is using something different than what you have programmed in. Try turning off the PL tones on your scanner if you have them enabled. If you don't or don't know what I'm talking about then you don't have them on and can disregard that.

The only thing I can think of is if they're moving to a TRUNKING system, they might have their dispatch channel patched in to the 800mhz, and I've noticed in the past when departments patched in their old vhf channel into the trunking some units you'd hear, and some you wouldn't. mostly like a one-sided conversation.

doesn't that scanner have CLOSE CALL on it? If so you might want to go park at the sheriff's office close to their tower and put the close call on and see what comes across your scanner.

 

[pinellasfirefighter]

most likely they are being dispatched over a laptop computer system in their cars like they do here in pinellas county.. now fire is even starting to use them.. but fire will never move away from voice dispatch completely..

 

[kb9tyc]

Polk County used to be dispatched on 155.550 and it was a repeater.

And like I said in the 8th post:

"Polk County is almost complete if not complete with a communications system upgrade so that may have something to do with it."