Thanks, Harry. Excellent job! I'll make sure and update the DB in the morning.
Mike
Appalachian Power (American Electric Power) -- migration to P25
- Thread starter mtindor
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Thanks, Harry. Excellent job! I'll make sure and update the DB in the morning.
Mike
it occurred to me that most of the voice traffic i hear form AEP is related to discussing opening and closing job tickets.
It is obvious that they are using mobile data terminals for this exchange and occasionally you get voice clues
as to where the units are located or to what function a talk group may have.
Do these MDTs us the same systems and/or frequencies as voice traffic?
The reason I ask is that DSD+FL indicates frequent "group calls" on my AEP P25 site with no associated voice traffic heard.
Just curious.
Thanks
It is obvious that they are using mobile data terminals for this exchange and occasionally you get voice clues
as to where the units are located or to what function a talk group may have.
Do these MDTs us the same systems and/or frequencies as voice traffic?
The reason I ask is that DSD+FL indicates frequent "group calls" on my AEP P25 site with no associated voice traffic heard.
Just curious.
Thanks
We are flying blind on most of this. I'm sure there is data on the system, and you should see that in DSDPlus in the channel window (where it indicates CC, VCC -- i think it might show data. Or amybe I'm thinking of Unitrunker.
But, I do wonder if they are actually using what we call "test signals" as data channels. Those are the wide (20 khz) wide channels, usually at least one per site, that exist after they move over to P25. Every site here in Ohio has at least one of them. And if you park on them with any application they cannot be decoded. They sound like a typical P25 test signal. But it would no sense for AEP to keep one or more freqs active 24/7 simply as P25 test signal -- in the case of Ohio for over a year or two. So those 20 khz channels might do something else, like carry data. Or they may have data access on a different band. I just don't know the answer.
And I don't have an answer for why you see group activity without any indication of ENC but also without any voice. I don't we see that up here in Ohio, but I haven't monitored the system since Novemberand can't remember.
Mike
Another insight from monitoring site 37.37... the alternate control channels being used as voice channels do not indicate the same signal strength as the primary control channel. The signal strength of these voice events, as indicated by the FMP24 band scope, is almost in the noise and probably why the decode is poor. Been running the SDS100 along side and voice decode is pretty good.
Wonder why there is so much difference in strength from control to voice channels? Are they not using the same site transmitter.
Wonder why there is so much difference in strength from control to voice channels? Are they not using the same site transmitter.
nd5y
Member
I have seen that on other systems, some with only one site. Not necessarily difference between control and voice channels but different signal strength on different channels. They should all have the same tx power and probably the same antenna so I don't know why it happens.
Yeah that’s what I thought so also. I thought it might be a problem with the RTL-SDR since the fast lane program retunes the SDR as defined by the control channel instruction. I have other P 25 systems that I monitor With the same hardware and it only happens on this one.
Took a little trip to Flat Top this evening
Confirming
Elgood WV (Mercer)
28.28, NAC 01C, 854.0875 CC, 854.6125 ACC, 855.4125 ACC
Neighbors indicated by DSD+FL
37.37 Flat Top 854.9125
42.42 White Gate VA 854.8375
Heard
White Gate VA (Giles)
42.42, NAC 02A, 854.8375 CC, 857.3625 ACC, 858.3625 ACC
Neighbors indicated by DSD+FL
28.28 Elgood WV 854.0875
66.66 Salem VA 854.8625
Also Heard
Gilbert (Mingo)
11.11, NAC 00B, 854.1125 CC, 855.0125 ACC, 855.5875 ACC
Neighbors indicated by DSD+FL
12.12 Dingess 855.3375
29.29 Logan 854.7625 (frequency different in Wiki)
I have not updated Wiki yet but will later this evening if you would like.
Harry
Confirming
Elgood WV (Mercer)
28.28, NAC 01C, 854.0875 CC, 854.6125 ACC, 855.4125 ACC
Neighbors indicated by DSD+FL
37.37 Flat Top 854.9125
42.42 White Gate VA 854.8375
Heard
White Gate VA (Giles)
42.42, NAC 02A, 854.8375 CC, 857.3625 ACC, 858.3625 ACC
Neighbors indicated by DSD+FL
28.28 Elgood WV 854.0875
66.66 Salem VA 854.8625
Also Heard
Gilbert (Mingo)
11.11, NAC 00B, 854.1125 CC, 855.0125 ACC, 855.5875 ACC
Neighbors indicated by DSD+FL
12.12 Dingess 855.3375
29.29 Logan 854.7625 (frequency different in Wiki)
I have not updated Wiki yet but will later this evening if you would like.
Harry
Great Job on confirming Elgood & White Gate Sites that can be added to the database.
Thanks, Harry. Great work, and very appreciated. I updated the wiki (and cleaned it up a little).
Mike
Thanks for wiki work...wasn't sure how much info was desired...probably go a little carried away 
Harry
Harry
Watching the band scope it appears that the noise floor rises at the voice channel frequency (about 5 mhz above control) to mask the signal. I changed to a different antenna with my RTL-SDR connected directly to the laptop and it did improve performance. I am getting voice decode now although somewhat choppy...still learning and having fun
I never had good success with listening. Most the time it was hard to understand.
DSD plus does not seem to like this particular system. Others that I have tuned in are usually very clear. That might prove the point that all P 25 is not created equal.
Definitely Sir you might be onto something
RR download of DSD format talk group list show Applachian Power talk groups as 1F6...I suspect they should be 1F7.
I changed them to 1F7 and they work now in event listings.
Correct?
I changed them to 1F7 and they work now in event listings.
Correct?
I think it does that because the AEP P25 system has multiple system IDs and RR has no way of knowing what talkgroups are associated with what system IDs. Some talkgroups could be systemwide, some could be tied to a specific site. Some could be statewide. But there is no way to diferentiate that in the database other than by having categories.
In your case, 1F7-land, it was appropriate for you to change them. And I would assume that is what somebody in 1F8/1F9/1FA/1F5 land would have to do as well. I don' think there is really any remedy for this -- other than manual editing like you did.
Mike
I agree I didn't find anywhere in the database info that made that connection between TG and System.
I first pasted the RR download into the DSD groups file as is but nothing showed up then i noticed the system was incorrect for the area.
The change made the difference. No big deal...
Thanks,
Harry
I first pasted the RR download into the DSD groups file as is but nothing showed up then i noticed the system was incorrect for the area.
The change made the difference. No big deal...
Thanks,
Harry
It probably would have taken me 2-3 days to figure that out. Glad you figured it out a lot quicker. I've only used that DSDPlus data download facility once, and it was on a system with a single system ID and thus I didn't see the issue.
I think the only thing RR could do is actually cause the generation of the full talkgroup list, with the talkgroups duplicated but with every system ID. Would look messy but would work. It's probably best for it to be left as is and let the user massage it like you did.
Mike
New site on line
Site: 73.73 NAC=049 ; Greenup Ohio
Neighbor: 92715.1F6-50.50 ; Rome
Neighbor: 92715.1F6-55.55 ; Ironton
Neighbor: 92715.1F6-59.59 ; Portsmouth
Neighbor: 92715.1F6-62.62 ; South Point
Neighbor: 92715.1F6-67.67 ; West Portsmouth
Neighbor: 92715.1F6-107.107 ; Pedro
Neighbor: 92715.1F7-2.2 ; Fallsburg
Neighbor: 92715.1F7-33.33 ; Huntington
Neighbor: 92715.1F7-74.74 ; Catlettsburg
Neighbor: 92715.1F7-75.75 ; Hitchens
Neighbor: 92715.1F7-76.76
Channel 0-259: 854.2375 SCC
Channel 0-297: 854.7125 SCC
Channel 0-431: 856.3875 CC
Channel 0-471: 856.8875 SCC
Site: 73.73 NAC=049 ; Greenup Ohio
Neighbor: 92715.1F6-50.50 ; Rome
Neighbor: 92715.1F6-55.55 ; Ironton
Neighbor: 92715.1F6-59.59 ; Portsmouth
Neighbor: 92715.1F6-62.62 ; South Point
Neighbor: 92715.1F6-67.67 ; West Portsmouth
Neighbor: 92715.1F6-107.107 ; Pedro
Neighbor: 92715.1F7-2.2 ; Fallsburg
Neighbor: 92715.1F7-33.33 ; Huntington
Neighbor: 92715.1F7-74.74 ; Catlettsburg
Neighbor: 92715.1F7-75.75 ; Hitchens
Neighbor: 92715.1F7-76.76
Channel 0-259: 854.2375 SCC
Channel 0-297: 854.7125 SCC
Channel 0-431: 856.3875 CC
Channel 0-471: 856.8875 SCC
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