Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
On Mon, 06 Apr 2009 13:17:03 -0500, you wrote: yes, remember the claims of 'extended dynamic range' ?? now, producers and 'artists' want every bit to be a '1' look at a current 'hit' with Adobe Audition it has all the 'dynamic range' of a concrete block Gary Everything has been compandored/levelized to death. Current pop music is just unlistenable. I'll stick to my vinyl records and hollow-state audio gear.
RE: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
Eyeing my collection of 80's era open reel tape. Anyone ELSE remember when open reel tape was an option with the music club. 8 track tape was too but not a cd in sight! Chris Kb0wlf Teac x-1000r and 700r -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:Repeater- buil...@yahoogroups.com] On Behalf Of John Gleichweit Sent: Thursday, April 09, 2009 1:26 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone? On Mon, 06 Apr 2009 13:17:03 -0500, you wrote: yes, remember the claims of 'extended dynamic range' ?? now, producers and 'artists' want every bit to be a '1' look at a current 'hit' with Adobe Audition it has all the 'dynamic range' of a concrete block Gary Everything has been compandored/levelized to death. Current pop music is just unlistenable. I'll stick to my vinyl records and hollow-state audio gear. Yahoo! Groups Links No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.285 / Virus Database: 270.11.43/2043 - Release Date: 04/08/09 19:02:00
RE: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
I'm getting ready to send my Teac 7010GSL back for refurbishing. I *STILL* love the sound of 10 1/2 NAB open reel tape... and I *ALWAYS* bought Maxell tape. ;-) Mark - N9WYS -Original Message- From: Repeater-Builder@yahoogroups.com On Behalf Of Chris Curtis Eyeing my collection of 80's era open reel tape. Anyone ELSE remember when open reel tape was an option with the music club. 8 track tape was too but not a cd in sight! Chris Kb0wlf Teac x-1000r and 700r
Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
At 11:26 PM 04/08/09, you wrote: On Mon, 06 Apr 2009 13:17:03 -0500, you wrote: yes, remember the claims of 'extended dynamic range' ?? now, producers and 'artists' want every bit to be a '1' look at a current 'hit' with Adobe Audition it has all the 'dynamic range' of a concrete block Gary Everything has been compandored/levelized to death. Current pop music is just unlistenable. I'll stick to my vinyl records and hollow-state audio gear. Some thoughts that are even more slightly off topic... 1000 recordings to hear before you die http://www.1000recordings.com/book/ And my stereo is also hollow-state mostly Heathkit but with new filter caps. yes, remember the claims of 'extended dynamic range' ?? I remember looking at the output of an early high-end CD player (Sony? I forget) on a scope. It had tremendous dynamic range. Much better then vinyl or even 7.5ips magnetic tape. Totally wasted with todays music. The only thing I could find that would max it out (i.e. run the output from rail-to-rail) was a Telarc 1979 CD of the 1812 Overture featuring REAL cannon. The CD case insert said that the producers were able to track down some of the original type of cannon that would have been used then. And it specifically warned that the recording could damage speakers. The Deutsche Gramophone recording of the same piece is almost as good - both bottomed out my subwoofers. Around the 4th of July some years PBS shows the old WGBH tape of the 1990 (or so) Boston Pops 4th of July show. The later years have the show at night but this is an late afternoon / early evening show and at the right point you can see John Williams picking up a handheld radio that he had on his music stand and cuing the Massachusetts National Guard that was sitting on the far side of the Charles river with multiple 155mm howitzers firing blanks. Not quite the same, but very impressive. They still do it - some years it's the Guard, other years it's the Army, other years it's appropriate era cannon. http://www.flickr.com/photos/antydiluvian/2178640689/ You can hear the cannons in this video of the last few minutes of the 2006 performance: http://www.youtube.com/watch?v=tzL_BY39vf0 Unfortunately you can't see much. Eleven civil war cannons (about a minute and a half) http://www.youtube.com/watch?v=LSyOumYb0wY The Japanese Ground Self-Defense Force Eastern Army Band and 1st Artillery Unit use 105mm cannons: (about 4 min) http://www.youtube.com/watch?v=w-4SRvGUtn8 (watch the flagmen giving cues in the second round of shots) BTW, how many folks know that the 1812 Overture (full title: Festival Overture The Year 1812 in E flat major, Opus 49) is about France invading Russia during the Napoleonic Wars? Despite being a staple at July 4th events it has nothing to do with any US / UK battle. We now return you to our (OT) APCO P25 horror stories thread. Mike WA6ILQ
Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
On Thu, 09 Apr 2009 01:44:55 -0700, Mike Morris WA6ILQ BTW, how many folks know that the 1812 Overture (full title: Festival Overture The Year 1812 in E flat major, Opus 49) is about France invading Russia during the Napoleonic Wars? Despite being a staple at July 4th events it has nothing to do with any US / UK battle. Mike, Agreed. Sousa's Stars and Stripes Forever is a far superior theme for the 4th of July! (GRIN!) Nate -- Nate Duehr n...@natetech.com
Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
At 4/9/2009 01:44, you wrote: At 11:26 PM 04/08/09, you wrote: On Mon, 06 Apr 2009 13:17:03 -0500, you wrote: yes, remember the claims of 'extended dynamic range' ?? now, producers and 'artists' want every bit to be a '1' look at a current 'hit' with Adobe Audition it has all the 'dynamic range' of a concrete block Gary Everything has been compandored/levelized to death. Current pop music is just unlistenable. I'll stick to my vinyl records and hollow-state audio gear. Analog is far from dead: the winner of the 2006 Grammy for best rock album, Stadium Arcadium, was recorded on analog tape. If you listen closely you can hear the tape hiss at the start end of each track. Bob NO6B
Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
Chuck, your experience parallels what many users in Pennsylvania have experienced. The only difference here is that the state continues to throw money at a dead animal believing that it can be made to stand. The general opinion here is that in very strong signal conditions (like in the lab) the system sounds OK. In weak signal locations and the real world the system can easily fall apart. Of course we are referring to the Ma/Com Open Sky system which is a proprietary digital system and is NOT P25. MIlt N3LTQ - Original Message - From: Chuck Kelsey wb2...@roadrunner.com To: Repeater-Builder@yahoogroups.com Sent: Tuesday, April 07, 2009 1:02 PM Subject: Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone? Have you read the engineering reports? I used one of the radios and wasn't very impressed (actually I was quite disappointed). And I was a cheerleader for the system up until then. Chuck And M/A-Com is suing the state because they DID meet the original specs/requirements, and the state is just trying to back out of spending the money. Crooked gov't? naaahhh... Yahoo! Groups Links
Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
The problem with both systems (and is also a problem with Ohio MARCS, which is Motorola Smartnet w/P25 audio, and MI too), is that they were designed and spec'd BY THE GOV'T to provide mobile coverage, not handheld coverage, and they are trying to use it with mostly handhelds. Also it was only designed to serve a few agencies (less capacity), and they are cramming everybody and their brother on it, so it overloads VERY fast. I've seen this time and time again, where an agency goes for a new system, and in order to save a buck, doesn't listen to the engineers, and they wind up with a system that doesn't cover what they want. Milt wrote: Chuck, your experience parallels what many users in Pennsylvania have experienced. The only difference here is that the state continues to throw money at a dead animal believing that it can be made to stand. The general opinion here is that in very strong signal conditions (like in the lab) the system sounds OK. In weak signal locations and the real world the system can easily fall apart. Of course we are referring to the Ma/Com Open Sky system which is a proprietary digital system and is NOT P25. MIlt N3LTQ - Original Message - From: Chuck Kelsey wb2...@roadrunner.com To: Repeater-Builder@yahoogroups.com Sent: Tuesday, April 07, 2009 1:02 PM Subject: Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone? Have you read the engineering reports? I used one of the radios and wasn't very impressed (actually I was quite disappointed). And I was a cheerleader for the system up until then. Chuck And M/A-Com is suing the state because they DID meet the original specs/requirements, and the state is just trying to back out of spending the money. Crooked gov't? naaahhh...
Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
Yes. I experienced both good and bad. When it works, it works great. When it doesn't, it's simply not there. The network experienced a lot of down time, lots of equipment failures, programming problems that were unresolved and then there were the more traditional coverage issues. These are all backed up by a third-party engineering firm, not just from results from the State itself. It's a real disappointment. I expected a lot more. I'm convinced that no vendor, at this point in time, can supply a system to meet the desired results. Chuck - Original Message - From: Milt men...@pa.net To: Repeater-Builder@yahoogroups.com Sent: Wednesday, April 08, 2009 9:03 AM Subject: Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone? Chuck, your experience parallels what many users in Pennsylvania have experienced. The only difference here is that the state continues to throw money at a dead animal believing that it can be made to stand. The general opinion here is that in very strong signal conditions (like in the lab) the system sounds OK. In weak signal locations and the real world the system can easily fall apart. Of course we are referring to the Ma/Com Open Sky system which is a proprietary digital system and is NOT P25. MIlt N3LTQ
Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
While this may be true in many instances, the New York State system was intended to accommodate a huge number of users. I read the engineering results several months ago (so some of the detail has already become a bit faded in the old brain), and lack of coverage was a minor issue in the entire scope of the rejection of the contract - there were plenty of other serious flaws indicated. Sure, Tyco has filed a lawsuit. I think everyone expected that. You don't simply take loosing a $3 Billion contract (more when you start adding user radios) lying down. Do I think New York State was worried about paying the bill right now with the economy where it is? Sure. But I don't think that the supporting data after several rounds of failed testing is fabricated political solution either. And for those who don't know, the radios for the NYS system all did P25 in addition to OpenSky format. Not sure if the OpenSky radios in Pennsylvania would do P25. I was personally disappointed in the system -- I was really thinking it was going to work and be the solution. And it may eventually be made to work - but it's not public safety grade right now, at least not in my opinion, based on outside engineering reports and a few, direct, personal experiences. We'll see what the courts say about it. Chuck - Original Message - From: wd8chl wd8...@gmail.com To: Repeater-Builder@yahoogroups.com Sent: Wednesday, April 08, 2009 9:24 AM Subject: Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone? The problem with both systems (and is also a problem with Ohio MARCS, which is Motorola Smartnet w/P25 audio, and MI too), is that they were designed and spec'd BY THE GOV'T to provide mobile coverage, not handheld coverage, and they are trying to use it with mostly handhelds. Also it was only designed to serve a few agencies (less capacity), and they are cramming everybody and their brother on it, so it overloads VERY fast. I've seen this time and time again, where an agency goes for a new system, and in order to save a buck, doesn't listen to the engineers, and they wind up with a system that doesn't cover what they want.
RE: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
Chuck / Jim, Chuck, your last paragraph says it all. THAT'S the bottom line on all of these new P25/digital voice systems - they are not ready for prime time. Public Safety radio requires a level of reliability that I don't think ANY vendor has been able to meet with P25 technology. Unfortunately, I see someone being hurt before this issue is truly realized. Jim... yes, many systems are engineered/designed around mobile access reliability/availability (the Illinois state system - STARCOM21 - specified 95% mobile access reliability in their RFP, I think. I have the system design document - 20 MB in PDF format...) and currently they are adding additional towers to accommodate portable access in higher populated areas, as well as more channels at the tower sites to accommodate the level of traffic on the system. But I think this will take YEARS before all the bugs get worked out. My biggest issue, as is yours, is the it's either there or not problem with digital voice technology right now. (I hope the manufacturers are listening to this!!) In the ham world, we use digital to communicate when you can't even DETECT the signal, but with these voice systems, it has to be PERFECT in order to be decoded properly. IMHO, we need to scrap the current VOCODER technology in favor of something more tolerant of a bit error level (or maybe employ error correction??). At least with analog, it the signal was down in the noise, you could still, in most cases, be able to discern what the person was trying to say. The other problem with the digital technology is that it does NOT play well with ANY background noise. Canine officers, officers at alarm calls, firefighters and others have experienced this first hand... and this is why they the fire service currently insists on analog on the fireground. Yes, the technology has GREAT potential but, IMHO, right now it is WAY too new for large scale deployment to public safety. Mark - N9WYS -Original Message- From: Repeater-Builder@yahoogroups.com On Behalf Of Chuck Kelsey While this may be true in many instances, the New York State system was intended to accommodate a huge number of users. I read the engineering results several months ago (so some of the detail has already become a bit faded in the old brain), and lack of coverage was a minor issue in the entire scope of the rejection of the contract - there were plenty of other serious flaws indicated. Sure, Tyco has filed a lawsuit. I think everyone expected that. You don't simply take loosing a $3 Billion contract (more when you start adding user radios) lying down. Do I think New York State was worried about paying the bill right now with the economy where it is? Sure. But I don't think that the supporting data after several rounds of failed testing is fabricated political solution either. And for those who don't know, the radios for the NYS system all did P25 in addition to OpenSky format. Not sure if the OpenSky radios in Pennsylvania would do P25. I was personally disappointed in the system -- I was really thinking it was going to work and be the solution. And it may eventually be made to work - but it's not public safety grade right now, at least not in my opinion, based on outside engineering reports and a few, direct, personal experiences. We'll see what the courts say about it. Chuck - Original Message - From: wd8chl wd8...@gmail.com To: Repeater-Builder@yahoogroups.com Sent: Wednesday, April 08, 2009 9:24 AM Subject: Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone? The problem with both systems (and is also a problem with Ohio MARCS, which is Motorola Smartnet w/P25 audio, and MI too), is that they were designed and spec'd BY THE GOV'T to provide mobile coverage, not handheld coverage, and they are trying to use it with mostly handhelds. Also it was only designed to serve a few agencies (less capacity), and they are cramming everybody and their brother on it, so it overloads VERY fast. I've seen this time and time again, where an agency goes for a new system, and in order to save a buck, doesn't listen to the engineers, and they wind up with a system that doesn't cover what they want.
RE: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
If it's either there or its not is supposedly a problem, you'll never see that go away in digital comms. You can bit-stuff FEC codes by the metric truckload into a signal all day long, but at some point, it just falls out. That's digital. Period. Anyone surprised by this must not be paying much attention to how these technologies work. MORE IMPORTANTLY: You can't LOWER channel bandwidth and retain audio quality and still have room for tons of FEC. Good old Nyquist and his mathematical friends... Hint: THE REAL ACHILLES HEEL OF P25 AND OTHER DIGITAL SYSTEMS... is that we're trying to implement them in LESS RF BANDWIDTH than the traditional FM analog signals. The natural progression should have been to convert to digital in the SAME channel spacing (expensive, and no economic gain, perhaps), and then start cranking up the compression over the years. The speed at which BOTH requirements were driven in, is painful for all. You mention that hams detect things using digital techniques, far down into well below the human ear noise floor on analog receivers. What you fail to mention is that those systems REPEAT the message over and over and over again. (WSJT, for example.) This isn't possible in a real-time voice system without using MORE bandwidth. It could have been done. Making a digital system that accurately reproduces telephone quality audio or better, and has multiple transmissions of the same bits (error correction) is certainly a no-brainer. (The entire telephone network runs on such technology these days... try finding an analog stepper switch at your local CO! Since they're not using RF paths that fade, and have other problems, their error correction needed is miniscule compared to an RF system.) Other's have also complained that the VOCODERs chipsets from DVSI introduce too much audio delay. I personally feel that complaint is a red-herring, since prior to audio delay on digital systems, there was always the feedback loop howl... same problem, just different timing and our ears aren't used to it. Once you get used to either one, you learn to move away from the loudspeaker... it's informal training, in most user's heads. Never seen any public safety radio folks go out to a parking lot and show anyone how to avoid feedback howl, but the users figured it out from seeing PA systems and people giving speeches, etc. But many probably don't easily make the mental leap that digital echo on-scene is the same thing. And I doubt anyone's got time to show them how to avoid the audio loop-back noise either, but if they give the users a hint that it's CAUSED by the same thing, they can apply their old head-knowledge to the new systems. (Don't stand next to the truck that has the big loudspeaker turned all the way up!) The engineering needed to deal with background noise is that it's going to take some super-duper DSP heavy hitter math to get RID of it prior to feeding the VOCODER. That's going to cost some serious bux... It's already common in the telco central office and audio/videoconferencing world, especially as packetization delays have been added by the move to VoIP on the long-haul circuits. Conferencing/wireline engineers have much easier challenges though, and can do things like ping the room for acoustics at the start of a call... or slowly slide in an adjustment for removal of echo as the bitstream passes by in the most advanced echo cancellers in the world. (Ever notice how most conference room speakerphones ding or play little snippets of music or similar at the beginning of a call? You think it's just another techno-noise, but the DSP is actually sampling the echos off the room walls, glass windows, etc... and adjusting the digital filters accordingly.) Unfortunately, the typical mobile radio user's environment is continually changing, they're not willing to pay $3000 a radio (well, some did... that was dumb), and that won't be as easy for the engineers to find the noise in math, and remove it, while still retaining voice quality. It'll take a while. And that $3000 leads to the most important concept, and why the lawsuits are flying. This stuff's expensive. I think the REAL issue is economics. Even though everyone here is a techie and analyzing the system's technical isuses -- the real question is... In order to double our channel space in public safety, is it worth four times the cost? (Ironically, cost vs. channel spacing maps out pretty closely to cost vs. RF power... it's a logarithmic function, if you ask me from a general knowledge of the price tags of these things.) VOCODERS and systems COULD have been deployed that did NOT cut the channel spacing roughly in half, and they would have sounded much better, worked much better, etc... but not only was it a system requirement to use less RF bandwidth, there are now laws in place saying everyone's gotta use less. Less is not always more, and this is an excellent example. Let the engineers build
RE: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
I agree entirely on the RF part of your article. But. Digital modes somehow eliminate feedback? Echo cancelation exists but a great deal of the time it fails miserably. You end up with voice-frequency delayed retransmission in the audio which IMHO is harder to understand 'through' than reasonable (ie - public safety person using lapel mic/HT to talk while inside the car with the car's radio's volume reasonably low) feedback. I personally don't understand the actual need (other than paying the FCC/Congress's bills) for all this nonsense of tightening up tx bandwidth. My scanner says theres a lot less on vhf/uhf than there ever was before as the business users all migrated to cellular. Is the 'real world' trick to just apply for 2 side-by-side 12.5k slots and run your big fat 25khz carrier down the center? ;) JS From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Nate Duehr Sent: Wednesday, April 08, 2009 2:25 PM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] (OT) APCO P25 horror stories anyone? If it's either there or its not is supposedly a problem, you'll never see that go away in digital comms. You can bit-stuff FEC codes by the metric truckload into a signal all day long, but at some point, it just falls out. That's digital. Period. Anyone surprised by this must not be paying much attention to how these technologies work. MORE IMPORTANTLY: You can't LOWER channel bandwidth and retain audio quality and still have room for tons of FEC. Good old Nyquist and his mathematical friends... Hint: THE REAL ACHILLES HEEL OF P25 AND OTHER DIGITAL SYSTEMS... is that we're trying to implement them in LESS RF BANDWIDTH than the traditional FM analog signals. The natural progression should have been to convert to digital in the SAME channel spacing (expensive, and no economic gain, perhaps), and then start cranking up the compression over the years. The speed at which BOTH requirements were driven in, is painful for all. You mention that hams detect things using digital techniques, far down into well below the human ear noise floor on analog receivers. What you fail to mention is that those systems REPEAT the message over and over and over again. (WSJT, for example.) This isn't possible in a real-time voice system without using MORE bandwidth. It could have been done. Making a digital system that accurately reproduces telephone quality audio or better, and has multiple transmissions of the same bits (error correction) is certainly a no-brainer. (The entire telephone network runs on such technology these days... try finding an analog stepper switch at your local CO! Since they're not using RF paths that fade, and have other problems, their error correction needed is miniscule compared to an RF system.) Other's have also complained that the VOCODERs chipsets from DVSI introduce too much audio delay. I personally feel that complaint is a red-herring, since prior to audio delay on digital systems, there was always the feedback loop howl... same problem, just different timing and our ears aren't used to it. Once you get used to either one, you learn to move away from the loudspeaker... it's informal training, in most user's heads. Never seen any public safety radio folks go out to a parking lot and show anyone how to avoid feedback howl, but the users figured it out from seeing PA systems and people giving speeches, etc. But many probably don't easily make the mental leap that digital echo on-scene is the same thing. And I doubt anyone's got time to show them how to avoid the audio loop-back noise either, but if they give the users a hint that it's CAUSED by the same thing, they can apply their old head-knowledge to the new systems. (Don't stand next to the truck that has the big loudspeaker turned all the way up!) The engineering needed to deal with background noise is that it's going to take some super-duper DSP heavy hitter math to get RID of it prior to feeding the VOCODER. That's going to cost some serious bux... It's already common in the telco central office and audio/videoconferencing world, especially as packetization delays have been added by the move to VoIP on the long-haul circuits. Conferencing/wireline engineers have much easier challenges though, and can do things like ping the room for acoustics at the start of a call... or slowly slide in an adjustment for removal of echo as the bitstream passes by in the most advanced echo cancellers in the world. (Ever notice how most conference room speakerphones ding or play little snippets of music or similar at the beginning of a call? You think it's just another techno-noise, but the DSP is actually sampling the echos off the room walls, glass windows, etc... and adjusting the digital filters accordingly.) Unfortunately, the typical mobile radio user's environment is continually changing, they're not willing to pay $3000 a radio (well, some did
RE: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
Hmm, I didn't say digital eliminated feedback. You have to go back to the original complaint (someone else) to understand my comments there. They said that at fire scenes and other places where loudspeakers are left on in emergency vehicles that digital sounds really bad when the speaker audio gets back into a fire scene radio. My contention is that we've ALWAYS had a feedback problem in that regard -- analog or digital -- but the PEOPLE using the radios UNDERSTAND the howling/squealing coming from an analog rig because they've seen it before in PA systems, at conferences, at the local baseball stadium. and they also understand how to avoid it. The people in the same situation today with digital radios have no mental frame of reference on what feedback sounds like in digital, so they don't move away from the loudspeaker. Eventually they'll get it. Nate From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Jacob Suter Sent: Wednesday, April 08, 2009 3:47 PM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] (OT) APCO P25 horror stories anyone? I agree entirely on the RF part of your article. But. Digital modes somehow eliminate feedback? Echo cancelation exists but a great deal of the time it fails miserably. You end up with voice-frequency delayed retransmission in the audio which IMHO is harder to understand 'through' than reasonable (ie - public safety person using lapel mic/HT to talk while inside the car with the car's radio's volume reasonably low) feedback. I personally don't understand the actual need (other than paying the FCC/Congress's bills) for all this nonsense of tightening up tx bandwidth. My scanner says theres a lot less on vhf/uhf than there ever was before as the business users all migrated to cellular. Is the 'real world' trick to just apply for 2 side-by-side 12.5k slots and run your big fat 25khz carrier down the center? ;) JS
Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
Chuck Kelsey wrote: The digital horror stories don't seem to be vendor-related either -- plenty of bad press on both Motorola and Tyco (MA-Com - was GE once upon a time). My state is a good example of a digital horror story. $3 billion statewide contract with Tyco cancelled for a system that didn't meet State specifications. Two counties built out as a test (my county one of them) 20 sites for my county alone. It's really too bad. I think that the concept was great. The problem (to me anyways) was that of an immature technology. Chuck WB2EDV And M/A-Com is suing the state because they DID meet the original specs/requirements, and the state is just trying to back out of spending the money. Crooked gov't? naaahhh... On-scene fireground is required to be ANALOG SIMPLEX by whatever agency certifies them...brain fart...IAFC? In any event, in the US, it is required to be analog simplex.
Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
- Original Message - From: wd8chl To: Repeater-Builder@yahoogroups.com Sent: Tuesday, April 07, 2009 10:12 AM Subject: Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone? And M/A-Com is suing the state because they DID meet the original specs/requirements, and the state is just trying to back out of spending the money. Crooked gov't? naaahhh... must be Illinois...
Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
Gary Glaenzer wrote: - Original Message - From: wd8chl To: Repeater-Builder@yahoogroups.com Sent: Tuesday, April 07, 2009 10:12 AM Subject: Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone? And M/A-Com is suing the state because they DID meet the original specs/requirements, and the state is just trying to back out of spending the money. Crooked gov't? naaahhh... must be Illinois... close-NY ;c}
Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
No, Probly Big M found an out for them to cancel the M/A Com deal and upped the kickback amount to the right person so they would buy from them instead. Mike - Original Message - From: wd8chl To: Repeater-Builder@yahoogroups.com Sent: Tuesday, April 07, 2009 10:43 AM Subject: Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone? Gary Glaenzer wrote: - Original Message - From: wd8chl To: Repeater-Builder@yahoogroups.com Sent: Tuesday, April 07, 2009 10:12 AM Subject: Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone? And M/A-Com is suing the state because they DID meet the original specs/requirements, and the state is just trying to back out of spending the money. Crooked gov't? naaahhh... must be Illinois... close-NY ;c}
Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
Have you read the engineering reports? I used one of the radios and wasn't very impressed (actually I was quite disappointed). And I was a cheerleader for the system up until then. Chuck And M/A-Com is suing the state because they DID meet the original specs/requirements, and the state is just trying to back out of spending the money. Crooked gov't? naaahhh...
RE: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
Only if it bears the Rod Blagojevich Seal of Approval (AKA: campaign donation) ;-p Mark - N9WYS -Original Message- From: Repeater-Builder@yahoogroups.com On Behalf Of Gary Glaenzer must be Illinois... - Original Message - From: wd8chl And M/A-Com is suing the state because they DID meet the original specs/requirements, and the state is just trying to back out of spending the money. Crooked gov't? naaahhh...
[Repeater-Builder] (OT) APCO P25 horror stories anyone?
Hello Group, As P25 is being rolled out worldwide, I have been hearing many stories regarding P25 shortcomings...Such as Vocoder problems in high noise situations, Jitter and Multipath issues from users that have converted from their legacy Analog systems, etc . The repeater issues (If any) are especially interesting for me, and would be very interested in hearing feedback from my colleagues from around the globe. Best regards to all Gareth Bennett
Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
Fire Departments in my local area are displeased with the digital systems I have read reports where the roaring noise of a fire in the back ground disrupted the communications resulting in casualties. The town I live in rolled back from a 800mhz apco p25 back to their analog VHF system. Best Regards, Chris Carruba Co-Admin irc.spidernet.org http://www.spidernet.org CompuTec Data Systems Custom Written Software, Networking, Forensic Data Recovery From: Gareth Bennett (Ihug) gare...@es.co.nz To: Repeater-Builder@yahoogroups.com Sent: Monday, April 6, 2009 5:58:02 AM Subject: [Repeater-Builder] (OT) APCO P25 horror stories anyone? Hello Group, As P25 is being rolled out worldwide, I have been hearing many stories regarding P25 shortcomings. ..Such as Vocoder problems in high noise situations, Jitter and Multipath issues from users that have converted from their legacy Analog systems, etc . The repeater issues (If any) are especially interesting for me, and would be very interested in hearing feedback from my colleagues from around the globe. Best regards to all Gareth Bennett
RE: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
Stick with analog, you can't go wrong. I see no reason for departments to convert over to p25. How much differently will it affect communications? You know the old saying, if analog works then why not stick with it, right? _ From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Chris Carruba Sent: Monday, April 06, 2009 7:30 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone? Fire Departments in my local area are displeased with the digital systems I have read reports where the roaring noise of a fire in the back ground disrupted the communications resulting in casualties. The town I live in rolled back from a 800mhz apco p25 back to their analog VHF system. Best Regards, Chris Carruba Co-Admin irc.spidernet.org http://www.spiderne http://www.spidernet.org t.org CompuTec Data Systems Custom Written Software, Networking, Forensic Data Recovery _ From: Gareth Bennett (Ihug) gare...@es.co.nz To: Repeater-Builder@yahoogroups.com Sent: Monday, April 6, 2009 5:58:02 AM Subject: [Repeater-Builder] (OT) APCO P25 horror stories anyone? Hello Group, As P25 is being rolled out worldwide, I have been hearing many stories regarding P25 shortcomings. ..Such as Vocoder problems in high noise situations, Jitter and Multipath issues from users that have converted from their legacy Analog systems, etc . The repeater issues (If any) are especially interesting for me, and would be very interested in hearing feedback from my colleagues from around the globe. Best regards to all Gareth Bennett
Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
With new systems, there are usually horror stories. Our county is essentially an ancient lake bottom and is very flat. We will be adding a 5th and possibly a 6th tower to support areas of poor coverage. I consider this a flaw in the original system design for this area. There have also been dead-spots with the traditional FM systems. One of our county's township's firefighter told me that they always switch to analog when arriving at an incident. Their lack of confidence relates in part to a structure fire when they heard a firefighter inside screaming for help to dispatch. Dispatch didn't respond until later when dispatch saw that the emergency button was triggered. Obviously, his transmission was going through the system and it was probably a surge issue at dispatch. Our county has a population of approximately 164,000 with three dispatchers for police, fire, and EMS. The emergency button flashes on all of their screens and also appears at the state-wide site. Our county APCO P25 trainer mentions that local acoustical noise makes the transmission difficult to understand and to be sure to hold the microphone 2 to 5 cm away from the mouth. He discourages the practice of using the microphone at arm's length. He also discourages the practice of clicking the PTT for an acknowledgment, as there is no squelch tail. I particularly enjoy the inter-operability and the instant display of the transmitting station's identification. I occasionally hear garbled voices during a transmission from a person in an area of poor coverage. We have not seen a large enough event to consume all of our talk-paths yet. Each of our towers has at least two different microwave paths. Our county is about 70 Kilometers in the longest direction. The Michigan State Police project is quite an ambitious system in area covered. About 250,000 square km and 10,000,000 population. Gareth Bennett (Ihug) wrote: Hello Group, As P25 is being rolled out worldwide, I have been hearing many stories regarding P25 shortcomings. ..Such as Vocoder problems in high noise situations, Jitter and Multipath issues from users that have converted from their legacy Analog systems, etc . The repeater issues (If any) are especially interesting for me, and would be very interested in hearing feedback from my colleagues from around the globe. Best regards to all Gareth Bennett
Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
The digital horror stories don't seem to be vendor-related either -- plenty of bad press on both Motorola and Tyco (MA-Com - was GE once upon a time). My state is a good example of a digital horror story. $3 billion statewide contract with Tyco cancelled for a system that didn't meet State specifications. Two counties built out as a test (my county one of them) 20 sites for my county alone. It's really too bad. I think that the concept was great. The problem (to me anyways) was that of an immature technology. Chuck WB2EDV - Original Message - From: Mike Naruta AA8K a...@comcast.net To: Repeater-Builder@yahoogroups.com Sent: Monday, April 06, 2009 10:44 AM Subject: Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone? With new systems, there are usually horror stories.
Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
Hello all, Big M just installed a P25 800 trunking system here that is a 5 site simulcast system. The M radios (xts2500 xtl5000) seem to work fairly well most of the time but there have been some totaly garbled too. Trying to listen on a scanner is another story, as is more garbled and sounds like Donald Duck talking if it picks up at all. The delay in audio from the vocoders between radios through the system is terrible . This delay causes problems if you have units in close proximity to each other where the other radios can be heard. I have heard that this delay really fouls things up when you have units on a scene like a wreck or fire where there is outside speakers being used..sounds like Reverb on steriods (if anybody remembers what reverb is). Most fire depts do switch to an analog direct channel for on scene comms because of this. Mike - Original Message - From: Gareth Bennett (Ihug) To: Repeater-Builder@yahoogroups.com Sent: Monday, April 06, 2009 5:58 AM Subject: [Repeater-Builder] (OT) APCO P25 horror stories anyone? Hello Group, As P25 is being rolled out worldwide, I have been hearing many stories regarding P25 shortcomings...Such as Vocoder problems in high noise situations, Jitter and Multipath issues from users that have converted from their legacy Analog systems, etc . The repeater issues (If any) are especially interesting for me, and would be very interested in hearing feedback from my colleagues from around the globe. Best regards to all Gareth Bennett
Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
On Mon, 6 Apr 2009, Chuck Kelsey wrote: My state is a good example of a digital horror story. $3 billion statewide contract with Tyco cancelled for a system that didn't meet State specifications. Two counties built out as a test (my county one of them) 20 sites for my county alone. It's really too bad. I think that the concept was great. The problem (to me anyways) was that of an immature technology. Kinda like D-STAR... /troll -- Kris Kirby, KE4AHR Disinformation Analyst
RE: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
Gareth, My state transitioned to a state-wide 700/800 MHz Motorola P25 system about 2 years ago, to replace their VHF High band / VHF Low Band system. So far, there have been a number of both complaints and accolades about the system - and it appears that what you hear depends upon whom you talk to. Many users on the street complain about motorboating voice quality, background that covers the actual message being conveyed, dead spots / inability to access the system when needed, etc. Other users gloat about the ability to be able to talk across the state from one mobile unit to another. My personal, unscientific analysis: when it works, it works well. When it fails, it fails VERY badly. It really depends upon the application - for business, it is most likely a very good protocol. For public safety, I have my reservations. If you want details, contact me off-list and I'll try to be of assistance. ;-) Good luck, and be sure to do your homework. you'll need it! Mark - N9WYS n9wys (at) ameritech (dot) net From: Repeater-Builder@yahoogroups.com On Behalf Of Chris Carruba Fire Departments in my local area are displeased with the digital systems I have read reports where the roaring noise of a fire in the back ground disrupted the communications resulting in casualties. The town I live in rolled back from a 800mhz apco p25 back to their analog VHF system. Best Regards, Chris Carruba Co-Admin irc.spidernet.org http://www.spidernet.org CompuTec Data Systems Custom Written Software, Networking, Forensic Data Recovery _ From: Gareth Bennett (Ihug) gare...@es.co.nz Hello Group, As P25 is being rolled out worldwide, I have been hearing many stories regarding P25 shortcomings. ..Such as Vocoder problems in high noise situations, Jitter and Multipath issues from users that have converted from their legacy Analog systems, etc . The repeater issues (If any) are especially interesting for me, and would be very interested in hearing feedback from my colleagues from around the globe. Best regards to all Gareth Bennett No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.0.238 / Virus Database: 270.11.42/2042 - Release Date: 04/05/09 10:54:00 image001.jpg
Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
Kris Kirby k...@catonic.us wrote: On Mon, 6 Apr 2009, Chuck Kelsey wrote: My state is a good example of a digital horror story. $3 billion statewide contract with Tyco cancelled for a system that didn't meet State specifications. Two counties built out as a test (my county one of them) 20 sites for my county alone. It's really too bad. I think that the concept was great. The problem (to me anyways) was that of an immature technology. Kinda like D-STAR... /troll -- Kris Kirby, KE4AHR Disinformation Analyst I've gotta concur with that comment! I was at a 'well known' ham radio store Saturday and they were showing off the D-STAR stuff. They tuned a local D-STAR repeater for me and were braggin on the quality, but the audio was OBVIOUSLY digital... sounded like my answering machine talking to me. I'm just not impressed with any 'all or nothing' communications technology... especially when it comes to public safety. Just my 2-cents. Mike WM4B
Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
Somehow, at some point, possibly about the time the compact disc was introduced, the world started defining audio quality solely as signal-to-noise ratio. Anyone with a new mobile device who mocks old analog bag phones has forgotten how great they sounded. 73, Paul, AE4KR - Original Message - From: mwbese...@cox.net To: Repeater-Builder@yahoogroups.com Cc: Kris Kirby Sent: Monday, April 06, 2009 10:59 AM Subject: Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone? I've gotta concur with that comment! I was at a 'well known' ham radio store Saturday and they were showing off the D-STAR stuff. They tuned a local D-STAR repeater for me and were braggin on the quality, but the audio was OBVIOUSLY digital... sounded like my answering machine talking to me.
Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
yes, remember the claims of 'extended dynamic range' ?? now, producers and 'artists' want every bit to be a '1' look at a current 'hit' with Adobe Audition it has all the 'dynamic range' of a concrete block Gary - Original Message - From: Paul Plack To: Repeater-Builder@yahoogroups.com Sent: Monday, April 06, 2009 1:09 PM Subject: Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone? Somehow, at some point, possibly about the time the compact disc was introduced, the world started defining audio quality solely as signal-to-noise ratio. Anyone with a new mobile device who mocks old analog bag phones has forgotten how great they sounded. 73, Paul, AE4KR
Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
It's amazing when talking to the techs deploying our regional 700 MHz P25 Mother /\/\ system about the requirements for SNR, they had absolutely no understanding of the concept of C/NR and how the existing analog UHF infrastructure already suffered from poor performance - simply replicating the exact same sites with 700 MHz digital equipment was simply engineering a doomed system. Too many times it seems the existing underlying issues of a system are overlooked or forgotten when deploying a new system directly on top of it. Oh well - my tax dollars at work... Again... On Mon, Apr 6, 2009 at 12:17 PM, Gary Glaenzer glaen...@verizon.net wrote: yes, remember the claims of 'extended dynamic range' ?? now, producers and 'artists' want every bit to be a '1' look at a current 'hit' with Adobe Audition it has all the 'dynamic range' of a concrete block Gary - Original Message - From: Paul Plack To: Repeater-Builder@yahoogroups.com Repeater-Builder%40yahoogroups.com Sent: Monday, April 06, 2009 1:09 PM Subject: Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone? Somehow, at some point, possibly about the time the compact disc was introduced, the world started defining audio quality solely as signal-to-noise ratio. Anyone with a new mobile device who mocks old analog bag phones has forgotten how great they sounded. 73, Paul, AE4KR
Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
not to worry it's 'DIGITAL' and that cures all ills. G - Original Message - From: AJ To: Repeater-Builder@yahoogroups.com Sent: Monday, April 06, 2009 1:23 PM Subject: Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone? It's amazing when talking to the techs deploying our regional 700 MHz P25 Mother /\/\ system about the requirements for SNR, they had absolutely no understanding of the concept of C/NR and how the existing analog UHF infrastructure already suffered from poor performance - simply replicating the exact same sites with 700 MHz digital equipment was simply engineering a doomed system. Too many times it seems the existing underlying issues of a system are overlooked or forgotten when deploying a new system directly on top of it. Oh well - my tax dollars at work... Again... On Mon, Apr 6, 2009 at 12:17 PM, Gary Glaenzer glaen...@verizon.net wrote: yes, remember the claims of 'extended dynamic range' ?? now, producers and 'artists' want every bit to be a '1' look at a current 'hit' with Adobe Audition it has all the 'dynamic range' of a concrete block Gary - Original Message - From: Paul Plack To: Repeater-Builder@yahoogroups.com Sent: Monday, April 06, 2009 1:09 PM Subject: Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone? Somehow, at some point, possibly about the time the compact disc was introduced, the world started defining audio quality solely as signal-to-noise ratio. Anyone with a new mobile device who mocks old analog bag phones has forgotten how great they sounded. 73, Paul, AE4KR
Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone?
You mean like a digital rectal exam LOL! Chuck - Original Message - From: Gary Glaenzer To: Repeater-Builder@yahoogroups.com Sent: Monday, April 06, 2009 2:29 PM Subject: Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone? not to worry it's 'DIGITAL' and that cures all ills. G - Original Message - From: AJ To: Repeater-Builder@yahoogroups.com Sent: Monday, April 06, 2009 1:23 PM Subject: Re: [Repeater-Builder] (OT) APCO P25 horror stories anyone? It's amazing when talking to the techs deploying our regional 700 MHz P25 Mother /\/\ system about the requirements for SNR, they had absolutely no understanding of the concept of C/NR and how the existing analog UHF infrastructure already suffered from poor performance - simply replicating the exact same sites with 700 MHz digital equipment was simply engineering a doomed system. Too many times it seems the existing underlying issues of a system are overlooked or forgotten when deploying a new system directly on top of it. Oh well - my tax dollars at work... Again... On Mon, Apr 6, 2009 at 12:17 PM, Gary Glaenzer glaen...@verizon.net wrote:
