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Dick you bring up good technical and adminsitrative examples. My
career too is in land mobile (public safety and railroads) and while there is plenty of trunking and digital taking place above 450 Mhz, there is also plenty of low and high band activity, and always will be. The ARRL seems to be doing a good job studying the BPL issue and informing the ham community, but the public safety, industrial, business, government, etc., users will have a louder and more credible voice (safety of lives & property, commerce, homeland security, etc.). I am wondering what the ARRL is doing to form coalitions with other (non-amateur) stakeholders, and to build concensus that has a loud and effective enough voice with the Commission and with Congress. Politically and techincally, the ARRL and/or the amateur community cannot stop this on their own. 73 Dan (K0DAN) On 14 Oct 2003 20:42:09 GMT, Dick Carroll wrote: dt wrote: Hams are not the only users of the affected spectrum. They may be the most vocal, but perhaps the easiest to discredit or deflect. What about the other users of the HF-thru-VHF spectrum? Police, Fire, EMS, Federal Government, Business, Utilities (the power companies themselves), Military, Aviation, etc., etc.? Do they not have consultants who are in touch with industry affairs? Does APCO (and other industry communications associations) not have knowledge about BPL and a position on it? Before I retired I was a field engineer working with a statewide public safety organization which uses low band VHF for base to car communications statewide, and that system is still virtually as I left it nearly 10 years ago. I have learned that they are aware of the BPL docket and filed in opposition, and have some idea that it will impact their communications, but I wonder if they have a clear view of what looms should BPL be widely implemented. While working I spent considerable time on RF noise issues, and I am rather sure that such a radio system cannot coexist with BPL. What happens is that when the noise intererence reaches a certain level, in a FM receiver the limiter saturates, and even a strong on-channel signal will not cause the squelch to open. The reciever remains quiet, and the call is unanswered. I was able to locate one troublesome noise source which was reported as repeater trouble in that the repeater would ocassionally go quiet in mid-transmission when a car was calling in. By the time I would drive the substantial distance to the repeater, a thorough checkout found no problem with the repeate equipment whatever. After several fruitless trips and attempts to find the trouble, I finally happened to be onsite when the trouble appeared, and it was all limiter saturation. Looking around outside while the noise was present in an attempt to spot a source in the local rural area, I soon found it- an arc welder in a shop several hundred yards away. When the welder was in use, the arc caused noise that saturated the receiver limiter, effectively shutting down the repeater. We relocated that repeater to a more isolated site where it still functions as intended. That example is but one case. BPL will, following power lines, also follow roads and streets since power lines follow streets and highway/road rights of way everywhere - the same places where police and highway patrol units'communications are active. The interference issue simply WILL cause something drastic to be implemented, what I don't know. If common sense has anything to do with it, BPL will be sent packing. Widesp[read implementation of BPL spells the end of lowband VHF use by public safety organizations. And with states' budgets in the deflated condition they are in most places, the funding will not be available to replace those systems in the forseeable future. I just called a former co-worker who is still working, and asked him if the organization knows that there is a BPL test site in the state. He said they did not. I suggested he might want to pass the word on up the chain so that they might want to send a mobile unit into the test area to get firsthand information on just what the effects might be. I'm also passing along all the info I've gathred here and from other sources. We'll need all the help we can get on this turkey. In short, I'm coninced that while APCO and others may know of the BPL docket I wonder if they have a very clear concept of what it will do to them where low band VHF is used. For instance, what have you heard from the state of Calorfinia, which is reported to use low band VHF for their statewide Highway Patrol, and has over 5,000 mobile units with no telling how many base stations? I have heard nothing whatever from anyone there on BPL. It seems evident that the BPL people are not publishing the existance of these very small test sites any more widely than necessary. So, they won't garner very many,if any, BPL-specific complaints, will they? And they'll be able to say "We must not be causing destructive interference since we haven't generated complaints". Of course limiting the numbers of users in test areas to a very few drastically limits the amount of interference potential. With so few BPL users online there *won't* be much interference caused, thus few or no complaints. Then they will conveniently pass over this fact, and the decision makers won't know the difference. Someone with clout needs to take them to task with the FCC and force them to use much broader test areas with much more realistic noise levels generated so that a more realistic noise picture can be evaluated. As it stands, they may well get what they want by default. Dick W0EX What is the ARRL doing to join forces with other affected spectrum users, perhaps forming a task force to promote common interests? Lobbying senators and congressmen, the Commission, NTIA, etc.? If the utilities' strategy is to divide and conquer, it appears they are being very effective. 73 Dan (K0DAN) On 14 Oct 2003 14:03:08 GMT, Dick Carroll wrote: W1RFI wrote: You raise an interesting question, Carl. How exactly should the average ham go about proving that the RFI is indeed BPL, when the BPL people say "That's not us!'?? In the case in Emmaus, the PPL rep told a reporter that Carl had misidentified a "neon sign" (in a residential neighborhood) as BPL. First, Carl is professionally adept with spread spectrum, so he knows what an SS signal sounds like. The signal was heard only in the trial area and when I was in Emmaus, I worked with a local in the trial area who downloaded files for me. When the download started, the noise started; when it stopped, the noise stopped. What really proves it to be not a neon sign, however, is that the time-domain (oscilloscope) signature of the received signal does not have a pronounced 120-Hz signature. Had the PPL representative actually looked at the signal, he would have known that his "explanation" was pretty transparent. I have extended by email a very cordial inviation for the PPL folks to attend a local club talk I gave; they did not respond. I then emailed a cordial invitation to work with them on interference issues; they did not respond. This boggles the mind, because if I were about to invest millions of dollars of my company's money and a national organization came to me and told me that there was a serious problem with the technology, and offered to drive over 200 miles just to show it to me, I think I would spend the hour or two and take a look. It's beyond obvious that the BPL people are adamantly intent on stonewealling and bypassing ham radio and anything else that tries to get in the way. They're aware that many of the impacted spectrum users are so widely scattered that much of the interference caused by BPL even when it becomes widely implemented they won't be noticed due to their limited exposure caused by lack of adequately close proximity. Hams, which *are* pretty well scattered throughout the population, should be ignored and their complaints deflected by such incorrect assertions as the above "neon sign" explanation. Make it so that there is so much question as to hams' competance to make such a call they can be portrayed to be wrong, whatever the facts. It's obvious obfuscation and an end-run around us, and whatever other protesters weigh in that can be similarily deflected. They hope that the "serious" users of that part of the spectrum will prove to be so few and widely scattered that their protests will be few and managable. And once BPL installations are widespread, they know it would demand a clearly demonstrated, very serious interference problem to csuse its abandonment, and they don't think that will happen. They maybe right. If so many users sign on that the sheer numbers of BPL users overwhelm all the protests of spectrum pollution and damage to communications sheer numbers and politics will prevail in their favor, they believe. All they really need to do is get it approved and "out there" in large amounts in most populated areas, then the situation will take care of itself, they think. If allowed to proceed, BPL will forever change usability of the HF and Low VHF part of the spectrum. |
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