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Damit, I am jealous. I lived in Florida for six years, but all before I started burning paychecks on Motorola gear
I am new to this forum as I am new to P-25, and have heard one audio sample of a P-25 transmission compared to an excellent FM transmission, and I must say that I can find no other example of superb quality of voice (save FM or TV Broadcast audio) in any radio service.
I've read through most all of the posts since 2004 and can say I'm glad APCO-25 is gaining momentum as opposed to D-Star, as I've heard some hams say D-Star leaves some things to be desired, including inferior audio quality, robustness, and non-standardness (as in non-native, non-IP-based transport layer).
I haven't read much about P-25's data stream capabilities, and I hope it has some, which would be excellent for Traffic-handling, such as the 2-year drills we have for accident-training for the Three-Mile-Island nuclear power plant in Middletown, PA, should an "incident" ever occur again as did occur in 1972 here.
The closest P-25 repeater to me (as far as I know) is in Allentown, PA, with the next closest in the Penn-Jersey Corridor region (Bucks, Chester, Montgomery, Delaware, & Phila. counties in PA + Camden, Burlington & Gloucester counties in N.J.).
I live in the Central Pennsylvania Dutch country region, closer to Harrisburg, PA; as such, I don't expect any repeaters using P-25 to go up within a 20-mile radius of me for the next 2 years (and I hope I'm wrong).
Since P-25 is a digital AND an IP-based protocol, I'd like to pose the following questions:
1. How difficult is it for someone with an analog repeater and internet-access to link up from a distance to a P-25 repeater (mixed-mode or digital-only mode) via a semi-permanent virtual circuit, and could the control-ops or users have the ability to enable/disable such a link? (hopefully, for the local end here to eventually become P-25 just as the distant end now is)
2. Assuming some exsisting P-25 repeater systems have internet access, could repeater owners here (who have analog repeaters, or even simplex repeaters, such as a private individual ham with a 50-milliwatt repeater in his backyard or neighborhood) be able to CONNECT to a P-25 repeater outside this region or state, via IP thru the internet, for the purposes of either INCREASING ham activity locally, and/or to expose hams (even if it's only partially-digital) to the EXPERIENCE of P-25 and what it has to offer and really sounds like?
3. Assuming the price of gear continues to decrease as more public-safety and other users sell or salvage radios/systems designed to work on P25, would it be feasable to build a trunked system in which most of the local/regional repeaters (especially the low-profile ones and the Echolink or IRLP-connected ones) could be accessible in fringe areas with other low-profile P-25 setups in those fringe areas covering several unused frequencies in the 70-cm band, or in the 33-cm, 23-cm or even the 2300 MHz. band? This would be akin to a cell-like setup, and hopefully could someday be within the financial reach of more aspiring hams wishing to set up handheld communications in their neighborhoods or even just in their homes with 10mW-like private repeater nodes.
I've read through most all of the posts since 2004 and can say I'm glad APCO-25 is gaining momentum as opposed to D-Star, as I've heard some hams say D-Star leaves some things to be desired, including inferior audio quality, robustness, and non-standardness (as in non-native, non-IP-based transport layer).
I haven't read much about P-25's data stream capabilities, and I hope it has some, which would be excellent for Traffic-handling, such as the 2-year drills we have for accident-training for the Three-Mile-Island nuclear power plant in Middletown, PA, should an "incident" ever occur again as did occur in 1972 here.
The closest P-25 repeater to me (as far as I know) is in Allentown, PA, with the next closest in the Penn-Jersey Corridor region (Bucks, Chester, Montgomery, Delaware, & Phila. counties in PA + Camden, Burlington & Gloucester counties in N.J.).
I live in the Central Pennsylvania Dutch country region, closer to Harrisburg, PA; as such, I don't expect any repeaters using P-25 to go up within a 20-mile radius of me for the next 2 years (and I hope I'm wrong).
Since P-25 is a digital AND an IP-based protocol, I'd like to pose the following questions:
1. How difficult is it for someone with an analog repeater and internet-access to link up from a distance to a P-25 repeater (mixed-mode or digital-only mode) via a semi-permanent virtual circuit, and could the control-ops or users have the ability to enable/disable such a link? (hopefully, for the local end here to eventually become P-25 just as the distant end now is)
2. Assuming some exsisting P-25 repeater systems have internet access, could repeater owners here (who have analog repeaters, or even simplex repeaters, such as a private individual ham with a 50-milliwatt repeater in his backyard or neighborhood) be able to CONNECT to a P-25 repeater outside this region or state, via IP thru the internet, for the purposes of either INCREASING ham activity locally, and/or to expose hams (even if it's only partially-digital) to the EXPERIENCE of P-25 and what it has to offer and really sounds like?
3. Assuming the price of gear continues to decrease as more public-safety and other users sell or salvage radios/systems designed to work on P25, would it be feasable to build a trunked system in which most of the local/regional repeaters (especially the low-profile ones and the Echolink or IRLP-connected ones) could be accessible in fringe areas with other low-profile P-25 setups in those fringe areas covering several unused frequencies in the 70-cm band, or in the 33-cm, 23-cm or even the 2300 MHz. band? This would be akin to a cell-like setup, and hopefully could someday be within the financial reach of more aspiring hams wishing to set up handheld communications in their neighborhoods or even just in their homes with 10mW-like private repeater nodes.
KA3RXE,
Welcome to the board.
One change to your post above, D-Star IS IP based as well.
In D-Star's current form, if you know the callsign of an operator you want to talk to and if the repeater you and the other operator are linked to the main database, then you can talk to that operator anytime, anywhere. (simple version)
The same can be done with P-25 machines, but the IP base I believe is a little on the expensive side to be cost prohibitive (corrections if I am wrong are welcomed please).
Another digital mode starting to take hold in the amateur world is MotoTRBO with a group in CO, already linking several machine via onboard IP.
No bashing P25, just adding information as I play with all three of the above.
Dan
KA8YPY
Welcome to the board.
One change to your post above, D-Star IS IP based as well.
In D-Star's current form, if you know the callsign of an operator you want to talk to and if the repeater you and the other operator are linked to the main database, then you can talk to that operator anytime, anywhere. (simple version)
The same can be done with P-25 machines, but the IP base I believe is a little on the expensive side to be cost prohibitive (corrections if I am wrong are welcomed please).
Another digital mode starting to take hold in the amateur world is MotoTRBO with a group in CO, already linking several machine via onboard IP.
No bashing P25, just adding information as I play with all three of the above.
Dan
KA8YPY
FYI:
For those traveling into the Philadelphia Metro area, there are currently four P-25 Ham repeaters on the air with fairly decent coverage throughout the city and surrounding areas.
These repeaters are:
For those traveling into the Philadelphia Metro area, there are currently four P-25 Ham repeaters on the air with fairly decent coverage throughout the city and surrounding areas.
These repeaters are:
- 443.100 MHz, Offset + 5.00 MHz, CTCSS: TX=203.5 & RX=131.8, NAC: 293
Philadelphia, Pennsylvania (Center-City)
--------------------------------------------------------------------------------------------------------------------- - 146.895 MHz, Offset -.600 KHz, CTCSS: TX/RX=192.8, NAC: 293
Pine Hill, New Jersey (Camden County)
--------------------------------------------------------------------------------------------------------------------- - 442.150 MHz, Offset +5.00 MHz, CTCSS: TX=156.7 & RX=131.8, NAC: 293
Camden City, New Jersey (Camden County)
--------------------------------------------------------------------------------------------------------------------- - 448.325 MHz, Offset -5.00 MHz, CTCSS: TX/RX=127.3, NAC: 293
Westampton, New Jersey (Burlington County)
---------------------------------------------------------------------------------------------------------------------
Austin Texas P25 Repeaters
There are 2 VHF and 1 UHF P25 Ham repeaters here in Austin..
146.940/146.340 107 NAC
146.680/146.080 123 NAC
442.650/+5 114 NAC
Also, if you're in the Austin area and need equipment at a good price, or help programming equipment, or help with anything P25, contact me: harmon@k5hdm.com
Thanks!
Harmon
There are 2 VHF and 1 UHF P25 Ham repeaters here in Austin..
146.940/146.340 107 NAC
146.680/146.080 123 NAC
442.650/+5 114 NAC
Also, if you're in the Austin area and need equipment at a good price, or help programming equipment, or help with anything P25, contact me: harmon@k5hdm.com
Thanks!
Harmon
K5tit
That guy was confused.. the K5TIT in dallas doesn't have a tone and it's DSTAR, not P25..
That guy was confused.. the K5TIT in dallas doesn't have a tone and it's DSTAR, not P25..
source for alot of HAM P25 repeater info by state
i have assisted the new owner of P25 Amateur Radio with organizing a page for each state's P25 ham systems, i have searched many sites for people posting P25 ham repeaters and organized all the info by state.
please check it out, its alot different now, i updated last week.
P25 Amateur Radio
i have assisted the new owner of P25 Amateur Radio with organizing a page for each state's P25 ham systems, i have searched many sites for people posting P25 ham repeaters and organized all the info by state.
please check it out, its alot different now, i updated last week.
P25 Amateur Radio
i suspect it is the free counter that was placed at the bottom, i noticed once that was there, my address bar at the bottom spent more time flip floping between several links that i had not seen before. ill notify the admin to remove the counter, and maybe we can find a different counter that doesn't contribute to the above situation.
KE5PL
Member
another P25
147.22+, NAC293. Midland County, Texas 2200' on a DB224. It has been up for 5+ years.
147.22+, NAC293. Midland County, Texas 2200' on a DB224. It has been up for 5+ years.
KE5PL
Member
doh!
Make that 200' on a DB224. 2200', I wish...
Make that 200' on a DB224. 2200', I wish...
reedeb
Member
Someday, when they all go digital that will be the end of my ticket.
Is there a better detailed list of USA P25 ham repeaters anywhere? There's so much cruft in this thread I can't find what I'm looking for, even with a search.
W2NJS
Member
The 2010-2011 ARRL Repeater Directory has a P25 repeater listing section beginning on page 715.
I think I found it, my membership was approved yesterday so I now have access to the files. APCO25hamradio : APCO 25 amateur radio
The 147.2850Mhz repeater in Edgar, Ontario (near Barrie) is now linked digitally with the 444.750Mhz machine in Toronto.
There's also a standalone dual mode repeater in Berkely, Ontario (south of Owen Sound) on 145.2900Mhz.
There's also a standalone dual mode repeater in Berkely, Ontario (south of Owen Sound) on 145.2900Mhz.
Baylink
Member
So, folks, here's a silly question: I've been hearing lots of "The grand P25 experiment has failed" chatter in various places, that all seems to amount to "The vocoder deals really poorly with background noise (and we weren't smart enough to design the radios with extremely low mic pre gains)". Is that truly the problem, is it insoluble, and how is it affecting ham P25 use?
It hasn't necessarily failed, it's a new technology still. They're still working on fixing the problems, in fact there will be a P25 Phase II standard coming out (no release date set, so it'll be a while). The users that seem to take the brunt of the complications are firefighters, who deal in noisy environments (next to pumps, fire, water hose, air tanks/respirators, etc).
Here's some really interesting information on PSCR tests that gauged the intelligibility of P25 modulation compared to straight FM modulation. You can actually listen to audio clips comparing the differences. They found that analog works better than P25 in some environments, and P25 works better than analog in some environments, and also that neither P25 nor analog works well an some environments. The Public Safety Communications Research Program
Here's a PowerPoint-style PDF that's a little bit easier to read and shows percent of intelligibility on each test: https://docs.google.com/viewer?url=...bout_pscr/highlights/iaff_redmond_nov2009.pdf
As for ham use, well, most of the P25 problems seem to be environment-related. Hams aren't usually operating in noisy environments. I haven't heard of any hams complaining about P25 problems. But let's say it this way: hams don't rely on their radios like public safety agencies do. Most ham repeaters aren't passing life-threatening traffic all day and all night. But a positive effect for hams is that there is more and more P25 surplus equipment coming into the market every day. I suspect we'll see a flood of P25 equipment come into the ham community once agencies upgrade from P25 Phase I to P25 Phase II when the Phase II standard is finalized and released (in the next decade or so, I presume).
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