Amateur P25 popularity…

[AK9R]

I'm talking about plain copper lines...been in use for over a century for transporting audio around the world.

I'm curious. How difficult is it to get dedicated wireline for repeater linking these days and how reliable are they? I say that because I routinely see telco tombstones that have been damaged, knocked over, covers off, wires hanging out, etc., and left unrepaired for months. It's as if the telco realizes that nobody is using wired telephones, so why bother maintaining the plant.

 

[rescue161]

Just because something is wireless doesn't mean that it doesn't use wired infrastructure.

 

[Project25_MASTR]

I'm curious. How difficult is it to get dedicated wireline for repeater linking these days and how reliable are they? I say that because I routinely see telco tombstones that have been damaged, knocked over, covers off, wires hanging out, etc., and left unrepaired for months. It's as if the telco realizes that nobody is using wired telephones, so why bother maintaining the plant.

It depends on the area as to availability. Today you'll often see something digital based with ADC/DAC conversion. Sometimes its via a fractal T1, sometimes it's straight IP and passed via MPLS. Sometimes it's old school copper. It's fairly reliable, just expensive.

 

[mmckenna]

I'm curious. How difficult is it to get dedicated wireline for repeater linking these days and how reliable are they? I say that because I routinely see telco tombstones that have been damaged, knocked over, covers off, wires hanging out, etc., and left unrepaired for months. It's as if the telco realizes that nobody is using wired telephones, so why bother maintaining the plant.

AT&T wireline announced that they'd stop selling conditioned copper circuits in my area back a few years ago. I still have several in use. I wouldn't try ordering a new one now.
The techs that really knew how to build out and maintain those circuits are gone (I hired a few of them). Now, you get a guy that understands two wires go from here to there, but that's about it. I doubt any of them could properly set up a circuit now.

If you watch the FCC notifications, you'll see a lot of notices about the big carriers abandoning their copper plants in parts of the country. Here's one that came through today:
DOC-384207A1.pdf

Copper cable plant has been abandoned in some areas, and all service is now on fiber. The copper plant is still in place, but no longer maintained in some areas. Again, the outside plant guys are gone, retired, moved on, died off. The newer techs don't have the skills to run the large plants like that any more. Carriers found it easier to migrate it all to fiber and just break out to copper for the "last mile". Easier for the techs, cheaper to maintain.
It's too bad, the old Bell System copper plant was a beautiful thing, verging on an engineering wonder of the world. No so much any more. I did hire an AT&T guy about 15 years ago as a field tech. He moved up to OSP Engineer, then took one of the younger techs under his wing and taught her everything he knew. She keeps our stuff running, still builds out a mean copper plant where I need it, but mostly engineers fiber systems now.

All my new stuff will be on my own IP network, a mix of fiber and point to point microwave. I've pretty much lost my confidence with AT&T wireline. They are no longer who they once were. Only thing left now is for all those big copper cables to start falling off the poles. There is good money (or, at least was) in pulling old cable and recycling it.

None the less, copper pairs did this for decades, and it did it well. "Back in the day", AT&T ran an excellent system and getting a circuit across country wasn't a problem. Heck, at one point I had a couple of dedicated AT&T ISDN/BRI circuits running from California out to Hawaii for some special usage.

 

[ladn]

None the less, copper pairs did this for decades, and it did it well. "Back in the day", AT&T ran an excellent system and getting a circuit across country wasn't a problem.

We had a 2-wire DC circuit to a remote (radio) base. Physical distance was about 10 miles, but I have no idea what the wireline distance was. It was an AT&T line and we had first rate service from AT&T. After the court-ordered break up of AT&T in the early '80's service went right down the toilet. One Baby Bell maintained our office end of the line, but another Baby Bell had the mountain top end and they wouldn't talk to each other.

We eventually phased out the remote base and transitioned to Nextel, but kept the high powered VHF radios in our cars for several more years. I still have my 90W, 4 channel Mitrek in the garage.

 

[mmckenna]

We had a 2-wire DC circuit to a remote (radio) base. Physical distance was about 10 miles, but I have no idea what the wireline distance was. It was an AT&T line and we had first rate service from AT&T. After the court-ordered break up of AT&T in the early '80's service went right down the toilet. One Baby Bell maintained our office end of the line, but another Baby Bell had the mountain top end and they wouldn't talk to each other.

We used tone remotes over them and they worked fine. Setting up the circuit was a challenge in the later years since the techs that knew how to set levels were few and far between.

We even had a few "OPX" lines, "Off Premise Extensions" off our PBX. Same thing, conditioned pair through the CO and to another location.

And yes, when you get into crossing LATA lines and have to deal with multiple carriers, it can be difficult. That was one of the reasons we kept good techs around that understood both ends of the circuits. Someone had to play the middle man and coordinate.

I still carry a buttset in my truck...

 

[Project25_MASTR]

I still carry a buttset in my truck...

I've found mine (with it's TDR) to be absolutely invaluable when it comes to figuring out exactly how much excess of the 1000 ft box of CAT5e the contractor pulled can be trimmed off for the two pair tone remote setup. (I cut 216 feet off one end and 50 something feet off the other end).

 

[N4GIX]

LOL, I completely agree. You still can’t talk around the world with an ht… this is what I dislike about hotspots. The expensive ht and hotspot may as well be a cordless phone you can buy at Walmart for $20. Only difference is that the phone operates in a different band but in some ways, hotspots are actually more basic because it’s not a private line. You’re effectively in a party line like you were for much of the 20th century… call 589 ring 2 and ask for Bob…

The major difference is that with a cordless phone you have to know someone's phone number, otherwise just dial randomly and hope whoever answers wants to have a conversation...
...on the other hand, with any form of ham radio contacts, you can be assured that whoever answers a "CQ" actually WANTS to have a QSO!!!

The above is precisely what I tell young people who make the cell phone a reason for ignoring amateur radio.

 

[N4GIX]

I got excited to get a P25 UHF radio to go digital, then I decided to listen to the P-25 capable repeaters to learn the nuances of the operators.

The takeaway I learned was that the local machine was quiet. All too quiet in the largest city in the State. When I rant to myself about the lack of amateur use of repeaters in Arizona, why get into a mode that has far fewer users?

When I first got into DMR it was simply because at that time there were ~38 DMR repeaters in the state of Indiana all linked to a single "Hoosier DMR" network. There was only one Fusion repeater that was out of range for me, two P25 II repeaters; one in Valparaiso, IN and the other in Chicagoland.

 

[BMDaug]

The major difference is that with a cordless phone you have to know someone's phone number, otherwise just dial randomly and hope whoever answers wants to have a conversation...
...on the other hand, with any form of ham radio contacts, you can be assured that whoever answers a "CQ" actually WANTS to have a QSO!!!

The above is precisely what I tell young people who make the cell phone a reason for ignoring amateur radio.

That’s fair. I’m not saying it doesn’t have a place at all. It helps newcomers learn the etiquette and some of the technical aspects, but it takes others completely out of the picture. I think you’re right that it’s a solid place to start because you can make tons of contacts which might pull you into the hobby. That’s a good way of looking at it, but I still think it’s more of a technical exercise than a significant achievement in the art of radio. Hopefully starting with a hotspot will drive someone to grow and explore, eventually moving towards a desire to make those contacts without the help of the hotspot.

On P25, for me, it is growing from a simple personal interest to a real safety and security skill. It’s driven me to become more involved with public safety organizations and perhaps towards a new profession!

-B

 

[kb9mwr]

P25 conventional operation is easier to program that DMR. The Astro Saber handheld of the 1990's is a beast you can use for self defense and it can be had cheap. The other good thing about P25 is that all the vocoder stuff has been out of patent for quite a while and the opensource version of the vocoder sounds good. I wish more hams would mess with P25 for all these reasons.

 

[vagrant]

Ohhh...Astro Saber as a...persuasion device. Those were the days. Windshields and noggin's feared the robust Astro Saber. They could also take a spill onto the ground while in pursuit and keep on working.

Anyways, prices are friendly enough for P25 radios and Motorola Quantar's are-a-plenty. I am only now figuring out TMS, so that will be fun to use as well.