Johnson County P25 System

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Jack007

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Okay, now I'm a little confused...
I just happened to take another look at the list of freqs and see that I have TWO 800s; but there's another list that shows several more. Also, "post rebanding"???

Can somebody please post the DEFINITIVE confirmed list of all these JOCO 700 system freqs?
I'd like to check it against what I've had loaded in my unit these last few months!

Jack007
 

RecoveryTow

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Hey everyone. I am looking at picking up a RS Pro-197 for a good price. My main purpose is to monitor Lenexa PD only. I am on rotation with them, and need to know if this unit will work with the P25 system. The specs say it works with the APCO 25 systems, so I am correct to assume it will work for what I need?

Thanks in advance!
Mike
 

MadSpleen85

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Hey everyone. I am looking at picking up a RS Pro-197 for a good price. My main purpose is to monitor Lenexa PD only. I am on rotation with them, and need to know if this unit will work with the P25 system. The specs say it works with the APCO 25 systems, so I am correct to assume it will work for what I need?

Thanks in advance!
Mike

Yes it will.

Just so you are aware. Lenexa Police use encryption on their secondary talkgroup, meaning you cannot monitor it with any scanner. You can monitor their primary dispatch talkgroup, this is where the calls are initially dispatched. If you are hoping to hear your company name coming up on the rotation before they call you, chances are you will not hear that on the primary talkgroup. Just something for you to keep in mind.
 

mancow

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If some of you in the outlying areas are looking for an antenna to listen to the JoCo system I have found a good one.

TinyURL.com - shorten that long URL into a tiny URL

It arrived today and I went from absolutely nothing to almost a full meter on the PSR800. It's about 5 feet long and is very well built. The specs say it's for the 700-750 range but it seems to work just fine with the upper 700s. The only issue I have is when the system utilizes one of the 800 frequencies. That is just too far out of range and the radio sputters but I'm happy with it since I can now listen to most of the traffic.

2011-05-04_17-12-25_747.jpg
 

MadSpleen85

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Mancow, what part of the area are you monitoring from? Just curious.

I don't think I have seen any antenna in the 700MHz range that are that large. If it works, thats what matters though.
 

n0lqt

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If some of you in the outlying areas are looking for an antenna to listen to the JoCo system I have found a good one.

It arrived today and I went from absolutely nothing to almost a full meter on the PSR800. It's about 5 feet long and is very well built. The specs say it's for the 700-750 range but it seems to work just fine with the upper 700s. The only issue I have is when the system utilizes one of the 800 frequencies. That is just too far out of range and the radio sputters but I'm happy with it since I can now listen to most of the traffic.

If you feel brave, try CAREFULLY nibbling off exactly 1/16 of an inch off each element on each side of the boom. The difference between in an ideal dipole at 725 MHz to 775 MHz is 0.1425 inch. Divide that in two for each side of the boom and you have 0.07125. 1/16 inch is 0.0625. If the center frequency was 725 MHZ then triming 1/16 inch off each side will raise the center frequency to around 765 MHz. If you have metal working skils and some tools, you could tune it to a slightly higher center frequency even still to put it at around 795 Mhz and split the difference on the two bands. Even though it says 700 - 750MHz., I doubt that it has a very wide band-width though (15 Mhz. tops...) The forumula is l=143/fx12, f is the frequency in MHz and l is the total length of the dipole. This is a good article on Yagi design and modification.
 

mancow

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I was actually thinking of doing this. I did the same thing recently to move a three element 154 yagi to 167 but I want sure if not being able to vary the spacing of the 700 beam would cause problems since there are so many elements.

Thanks for the info. When the weather dries out I will try it. I'm sure cutting those elements will be a pain in the ***. I suppose I can use the saws all with a metal blade.
 
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mgolden2

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Wirelessly posted (Mozilla/5.0 (iPod; U; CPU iPhone OS 4_2_1 like Mac OS X; en-us) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8C148 Safari/6533.18.5)

If you think about it, maybe take before/during/after pics and post those too!
 

n0lqt

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I was actually thinking of doing this. I did the same thing recently to move a three element 154 yagi to 167 but I want sure if not being able to vary the spacing of the 700 beam would cause problems since there are so many elements.

Thanks for the info. When the weather dries out I will try it. I'm sure cutting those elements will be a pain in the ***. I suppose I can use the saws all with a metal blade.

The actual difference in element space between 725 MHz and 775 MHz is on the order of a 1/64 of an inch. It will change the feed point impedance a couple of ohms (less than 1 db loss) and will change the antenna pattern somewhat. It may make it a little more directional or possibly add a side-lobe.
 

MadSpleen85

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Anyone else still monitoring the old Fire/Med-Act analog dispatch frequency? Unless my old RS-2040 has taken a dump on me, I have not heard anything toned out in about a week or maybe longer.

Anyone know what the county decided to go with as far as station and personnel alerting?
 

kb0gus

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If some of you in the outlying areas are looking for an antenna to listen to the JoCo system I have found a good one.


It arrived today and I went from absolutely nothing to almost a full meter on the PSR800. It's about 5 feet long and is very well built. The specs say it's for the 700-750 range but it seems to work just fine with the upper 700s. The only issue I have is when the system utilizes one of the 800 frequencies. That is just too far out of range and the radio sputters but I'm happy with it since I can now listen to most of the traffic.

2011-05-04_17-12-25_747.jpg

Mancow... did you get this installed? How does it work? Has anyone had any luck using a yagi in the middle of the county to help alleviate simulcast distortion?

I picked up the same antenna of ebay and am thinking of trying it... I just am lazy and don't wanna jack with installing it, running the cable, etc if I don't have to as I don't have any other external antennas.

Thanks!
 

mancow

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It works very well in pulling in distant 700 stuff but I still get distortion due to simulcast and I think there really is no way around that due to my location being out of county. I'm not sure how it would perform in county where you are trying to pinpoint a certain tower.

I am still intending on climbing up on the roof to trim it a bit for the upper 700 range but haven't got around to it yet.
 

CWR

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I have a question on the Jo. Co. 700MHz frequencies in the data base.
I thought I was missing some , so I added.
772.9875
853.775
853.9625
And I went from reception , to NO reception.
SO , I checked the FCC Database
772.9875 comes back No License Found
AND , 853.775 & 853.9625 are listed as part of another trunked system in the county.
So , I took the above frequencies back out , and everything is working fine now.
Any thoughts ? ? ?
 

hkrharry

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I have a question on the Jo. Co. 700MHz frequencies in the data base.
I thought I was missing some , so I added.
772.9875
853.775
853.9625
And I went from reception , to NO reception.
SO , I checked the FCC Database
772.9875 comes back No License Found
AND , 853.775 & 853.9625 are listed as part of another trunked system in the county.
So , I took the above frequencies back out , and everything is working fine now.
Any thoughts ? ? ?

They are migrating the old trunked freqs into the new 700 mhz system, yes the new radios do that,

You only need the control channels in your rig that ought to make things Ezer to load.

Also at some point later this year look to see the new KCMO P-25 & JoCo 700 P-25 get linked together
for the new regional super system called "MARRS". BTW incase any of you over here have not been following the Missouri List the new P25 KCMO is spitting RF and a lot of testing activity.

Hey OP100 check out Dwight's paper on the station alerting : http://tinyurl.com/JoCoStationAlerting

It was written in Nov 2007, Dwight frequents the list here maybe he will chime in on an update.

HH
 

CWR

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I'm just saying , I don't think those 3 frequencies ;
772.9875 , 853.775 , & 853.9625 , are part of the 700 MHz trunked system.
Search the FCC Database and draw your own conclusions................
 

MadSpleen85

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.....

Hey OP100 check out Dwight's paper on the station alerting : http://tinyurl.com/JoCoStationAlerting

It was written in Nov 2007, Dwight frequents the list here maybe he will chime in on an update.

HH

Yeah I remember looking that over when the digital system was just being funded to become a reality.

Locution is still in use it seems. I listen at least 8 hours everyday and in the past week I have heard at least 4 different units reporting a problem with Locution not activating when a call was dispatched. That is the only alerting that I have heard mentioned.
 
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