MD state 800 System

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n3vbj

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Has anyone heard when MSP and DNR/NRP and most other state agencies are switching to Digital 800 Mhz? The MDTA and Port authority have a Tower on the ports property in Dundalk/Baltimore City.. Most of the Counties have gone Digital I wonder if the State will switch soon. I still hear a little on the 39Mhz and some on the 151 Mhz repeaters.
 

ka3jjz

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Check these threads out - you will have a better understanding of the subject

http://forums.radioreference.com/ma...and-area-regional-communications-p25-trs.html

http://forums.radioreference.com/ma...n-forum/231503-maryland-first-700mhz-trs.html

Now as for MSP - at least for now, many (though not all) are piggybacking on their respective county's trunk via portables and some dedicated mobiles - and all are documented here...

Md. State Police - the RR Wiki

I still get lots of activity on 39 mhz outlets...Mike
 

n3vbj

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MSP/NRP 700/800Mhz systems

Thanks Mike,

I remember your Strong Signals Web Pages from the past and on the Brats repeater.


Right after I posted I fired up my PSR500Edit program and checked MD Trunked Baltimore and added those to my Pro197 and Pro 106 scanners. I have yet to hear anything there yet I did see 1 hit on the hits for one of the test groups but no audio, it was a 4 digit ID so i surmise it was from Pikesville MSP At the EOC. I was reading a PDF from one of the other threads on Maryland systems show this system must be up by April 2013. MSP will still use Low band and simulcast until it fully functional, mostly inter agency will use it until it switches for good. I hear by Nov of 2012 to test it and full switch over by April of next year

I have a Tower at the Dundalk Marine Terminal less than a mile from my house and Baltimore Co's Tower at precinct 12 that I can see less than 1.5 miles. I have very few problems with P25 multi path I hope it will be the same with the state system. I have Fort McHenry Tunnel and Francis Scott Key Bridge MDTA will be on that as well so I should hear every thing. Stubbys work best all over Baltimore Co even on the North end and south ends of the county. Chatters a little near 83 and Md line (Hearford zone) I Think the P25 systems in use are far clearer and much better coverage than any 800 Mhz analog system any where.

I think most people are upset now that they found out my Pro 97/97 and my Pro 2096 may or may not reband to the new system and the DSP's are 4 years old if it rebands and sounds like crap cause it's hooked up to a discone on the roof and everything sounds like it underwater! I went out and spent $300.00 on new Digital scanner and hooked up to the same antenna and it sounds the same. Why did they have to go Digital the old system worked fine and I could have saved $300.00 I try to tell them it's not your scanner it the antenna. use a stubby on your Portable and take a PL-259 and turn it upside down and soldier a 4 1/2 inch 12 gauge wire in the center. 4 4 1/2 inch wires and (4) 440 screws and 2 washers and a nut on the 4 holes and bend the wire down to a 45 degree wire. take some TV coax and get a 75 Ohm F to PL-259 male adapter and screw it to the bottom of the antenna you made and put it up on a shelf or out in the open. Get a 75 ohm female to BNC or SMA for your scanner and see the differences in your High Gain antenna outside and this 800 Mhz Vertical . Outside antenna underwater........ indoor vertical crystal clear P25 decoded Audio.
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Jerry Cimildora N3VBJ
 

ka3jjz

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Don't get your apples and oranges mixed up - you're going to end up with mush :.>>

Rebanding has nothing to do with the new 700 mhz system (not 800) nor does it have anything to do with the Baltimore county P25 system. We have a separate thread for that, by the way. In addition the 2096 can be rebanded, but that's quite OT for this discussion...

As you correctly implied, multipath issues are a big problem with this new LSM modulation that these newer systems (such as Baltimore city and Baltimore county) are using. The Unidens don't do very well with this. It would appear that the RS/GRE models have more (although not complete) success with it. Whether the new 700 mhz system will be using LSM is anyone's guess at this point - I don't think that has been decided yet, although I could be wrong about that. I don't even know if they will be using Phase II which no scanner can handle at all (The PSR800 can handle the beta flavor of this scheme..)

I suspect that what will happen is that MSP will use the 700 mhz system when they can, and if they have coverage issues, will revert back to 39mhz. That is the pattern they use when they are using a county trunk - for example, on the Upper Eastern Shore Consortium system. So I wouldn't prepare to drop any 39 mhz programming just yet.

Mike
 
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