Simulcast P25 system - should I choose closest sites or all of them?

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theTastyCat

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Hey all - trying to receive Metro Nashville PD on my new TRX-2, which I believe is simulcast P25. Having zero luck. Also zero luck receiving the TACN network, which is used by dozens of agencies and has repeaters all over the place. As a ham, I figured the closest few repeaters would minimize it trying to hunt around for a signal, but some reading I've just done is confusing; should I leave them all on and let it decide? Especially as this is for a mobile install.

Also any tips as to why I'm not getting Metro or TACN would be greatly appreciated :)

Many thanks, all!
 

an39511

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I use a high gain Yagi and turn on attenuation. Aiming at the closest site may not bring good results because there may be another tower behind the one you are aiming at down range. In my case I aim at a tower that has nothing around it. I use a 14db gain antenna with a very narrow receive path. It took a lot of aiming and testing during different seasons to find the best reception.
 

theTastyCat

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Gotcha. This will be for a mobile installation for me; would it be better for me to use all sites or not?
 

buddrousa

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I had a friend in Hendersonville before he moved and the TACN is solid in that area. I also this summer run I-24 into Nashville downtown and worked the TACN system from several miles in Ky all the way in on the rubber duck antennas with a Uniden 436 and Radioshack 668.
 

GTR8000

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Let's be clear about this. Simulcast means "Simultaneous Broadcasting", which means in a P25 simulcast cell you have multiple RF subsites transmitting the exact same signal on the exact same frequencies from different physical locations simultaneously.

In other words, there is really no way to "pick" which repeaters at which site you want to monitor. It's all the same signal floating through the air on the same frequencies.
 

buddrousa

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The TACN is not a simulcast system in the West Tn 20 sites are not the same frequencies. Not sure how thetastycat has his setup but mobile I get most sites at 30 plus miles TRX and x36 both and 40 plus miles on my 25 foot ST2 base antenna.
 

theTastyCat

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I may be using the wrong terminology - sorry guys. What I'm asking is this: in EZScan, I have the option to select which sites of a multi-site system I want to monitor. Metro Nashville PD gives me three sites while TACN probably has 50. Should I monitor all of them or just those I think I will be closest to? Seems to me that using all of them would help while mobile but would it slow down scanning?

Also trying to figure out if it's me using the stock antenna indoors or simulcast distortion that's making my audio sound so weird, and if so, if this is part of the problem...

Thanks all!
 

buddrousa

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I only use the number of sites it takes to hear at home I use 5 when I travel West Tennessee I use all 20.
But you are true the more sites the longer the scan times.
I would find the sites I hear at home and make one playlist then I would make a playlist for my travel areas
 

theTastyCat

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Makes sense. Is there any relatively simple way to monitor each site individually to test or do I need to reprogram the scanner every time?

Sorry for all the dumb questions - I really appreciate all the helpful responses. Steep learning curve to these new scanners but totally worth it!
 

buddrousa

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When I go out mapping TACN sites I setup 20 systems one site per system and run pro96com on a laptop on a Radioshack PRO18 or PRO668 both program just like the TRX. So what I am getting at is you can setup 5 or 6 one site systems and test for what works best for you.
 

theTastyCat

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Thx buddro - trying to understand! So would that be the same as 5 or 6 scanlists and see which ones I'm receiving from the most frequently?
 

buddrousa

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Yes that is the way I do them is name the TACN 4-20 TACN 4-22 ect and put only one in each scan list until I get done testing
 
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