New PSR-800 User Trying to Tweak P25 Setting

[KA5YYD]

Bottom Line Up Front: I am trying to set up my new PSR 800 to efficiently receive my local public service agencies that have transitioned to the new City of Houston P25 phase II network.

I have had my PSR 800 a couple of weeks now and have managed to get my local agencies programmed onto scanlists. However, even though I have only a few items in the scanlist, for conventional frequencies, the PSR 800 picks up conversations a number of seconds after my ham radios scanning the same frequencies pick them up. For example, if a unit calls in, I hear it on my ham radio. If I am lucky, I get the dispatcher's response on the GRE.

When I pick up a digital transmission, the audio is remote sounding and "computer-like." I am often getting bits of transmissions and rarely an entire conversation. It also seems like the signals are very weak, as antenna positioning seems critical. I know the design specification for the Houston system was that an HT on a belt should be able to reliably bring it up, so I would assume I should have similar signal strength on the P25 system as the local conventional systems, but I appear not to.

As I understand it, the City of Houston system which my local cities (the Memorial Villages on the west side of Houston) are now using/transitioning to (the Village Fire Department is there at talkgroup 31009, I am not sure how far along the PDs are yet, although they have talkgroups in the database) is a part of a bigger system called the "Texas Wide Area" in the database and is one of two systems with the same alpha tag (bad in my estimation). Specifically, it is the one with the type "Project25." When I look at the Trunked Site Information in EZ Scan, I find 66 sites in various areas, some of which are more than 100 miles from me. I suspected that part of the apparent scan delay is that the scanner was individually listening to all of those sites and perhaps every frequency on each site, so that was part of what was slowing me down. So, I locked out the sites that are clearly a long way off. Was that the right thing to do? I have not been able to tell a difference, but if that is what needs to be done, maybe I should lock out a few more to reduce the time spent scanning frequencies that are not going to do me any good.

It occurs to me that my marginal reception may be caused because the scanner is picking up my talkgroup on a site remote from where I am and has no way of finding the strongest signal on the trunked system for where I am. Is that correct? In other words, do I need to figure out where the towers are and only listen to the one or two on the trunked system that are closest to where I am at a particular time to get reliable reception?

If the answer to the above is yes, how do I do that? The truncated alpha tags in the software for the sites include multiple identical entries for "Houston Public S" or "Houston Public W" which I assume are sites on the south and west side of Houston, respectively. How do I determine the physical location of each site? I have just gotten pieces of transmissions on the P25 systems (Showing up as D2 on the top line of the scanner). Is there something that is on the scanner display that will help me identify the site I am actually hearing when the scanner stops on a talkgroup? So far, I have not gotten it to stop long enough on a D2 transmission to allow me to hit the SEL button to stop it and let me see what all is being displayed.

I have been trying "self help" through trial and error and am getting frustrated. Would appreciate some elmering.

Thanks and 73.

 

[Ed_Seedhouse]

B However, even though I have only a few items in the scanlist, for conventional frequencies, the PSR 800 picks up conversations a number of seconds after my ham radios scanning the same frequencies pick them up.

Your ham radios are going direct to the output frequencies and hearing them immediately, because they make no attempt to use the trunking features of the system. Your scanner has to listen to the control channel, then jump to the frequency for the talkgroup first selected. And when that conversation stops it has to check the control channel again. The bonus is that your scanner can follow the conversation as it hops from frequency to frequency, which it often will on large trunk systems. Your ham radio can't do that, so you will often only get bits of the conversation. So "that's not a bug, that's a feature".

 

[KA5YYD]

Your ham radios are going direct to the output frequencies and hearing them immediately, because they make no attempt to use the trunking features of the system. Your scanner has to listen to the control channel, then jump to the frequency for the talkgroup first selected. And when that conversation stops it has to check the control channel again. The bonus is that your scanner can follow the conversation as it hops from frequency to frequency, which it often will on large trunk systems. Your ham radio can't do that, so you will often only get bits of the conversation. So "that's not a bug, that's a feature".

Thanks for the response. Although I am no expert in trunked systems, I understand there is some overhead associated with getting the radio set to the right frequency, etc. once there is a transmission on a talk group. However, my ham radios are not set up to monitor the trunked systems. I made this observation when using the PSR-800 side by side with the ham radios while scanning conventional UHF FM frequencies on the ham rig and a handful of conventional UHF FM frequencies and a handful of P25 phase II talk groups on the PSR-800. That is what led me to believe I have my PSR-800 set up in such a way that it is scanning "too much" in the way of sites and/or frequencies on the trunking systems, since I don't know any other way to explain what appears from the user end to be "slow scanning." I seriously doubt that is the issue, so I am trying to figure out what else it could be, because if this is as good as it gets, it is not very good. I am figuring it is operator error, I just have not figured out where.

 

[IowaGuy1603]

I had both of my 800's running side by side yesterday (after I tweaked them)..................One was catching things faster than the other.

Both are set up exactly identically.

When using a scanner you are going to miss things......that is a fact of life and is a product of using a single receiver to monitor multiple sources.

It often takes a bit of balancing to get that correct mix that YOU wish to listen to.........


The nice thing about the 800---is that you can experiment. Set up your trunked system split up in 2 scanlists and see if you hear things better.. If it doesn't work format it and go back to your "control" card -----------------------(which you kept before you made changes)

Experiment with the V-Scanner folders to see if that way of organization works for you-----if you dont' like it, you just erase and go back to a config that you know works best.

 

[troymail]

If I'm reading the situation correctly, you're right on track to the problems. You're probably dealing with the LSM modulation issues coupled with the radio's attempt to check/scan all 66 sites to find something to lock onto.

Take a look at these posts:

http://forums.radioreference.com/gre-scanners/257708-psr-800-confusion-multi-site-workaround.html

and more specifically this one:

http://forums.radioreference.com/gr...fusion-multi-site-workaround.html#post1892759

 

[danw5211]

I have a similar situation here with the MSWIN statewide system. I am surrounded by 4 tower sites at +15 miles. A second ring of towers at +30 miles. I locked out all of the 145 towers in Mississippi but the 8 closest towers. 4 for home use and the second ring for mobile use. No problems so far. Although our system use is probably far below the Houston system use.