Ray, I may be able to be of assistance in this area.... grab a cup of decaf, and read on...
It sounds as if these guys are working on a buffer based system. AS FM Broadcasting rules have been referenced before, we will call this approach the 73.207 approach, which is a "minimum distance" type of spacing system. Even the Commission allows "contour protection" based applications under 73.215. The first item to approach is to be absolutely sure you are making a valid request. This will require very accurate parameters to begin the studying process, and you may be required to contact the repeater trustee directly to gain this information. Try to sell them the idea that you want to be a good neighbor, and protect their existing coverage... not encroach upon it. If you get the surrounding trustees on board, it will work to your advantage. I would suggest terrain along a minimum of 36 radials, using a minimum of 3-arc-second data. In mountainous terrain, you should increase the resolution to 360 radials, and possibly even Longley-Rice studies to support your request. I do have 1-arc-second data, but it can be somewhat overwhelming to try to use for large areas of study. I had to produce a ton of studies for my 6m pair. I based my studies on ERP, HAAT, and the report by Roger B. Cary (which the Commission considers to be the "Radio-Rosetta" when it comes to LMR allocations). Then the coordinating council in my area had a database crash, and used a 3 yr old back-up to try and recover. My pair has since been re-allotted to another nearby location. Hence, I will be re-visiting this mess once again. When I made my pleading the coordinators were so overwhelmed with accurate data that they didn't possess... that the President of T-MARC asked me to take on the job... I declined. Just too much on my plate to assume the position, and I am not really too hip to the politics they employ. I don't recall the exact signal levels at this time, but I can provide a copy of the Carey Report to any interested parties and for posting on the RBTIP. The methods in this report are based on D-to-U ratios and reasonably valid propagation curves. In other words.. sound engineering practice. You will need accurate data as well as cooperation of your neighboring repeater owners to accomplish this. To make a long story short, I have come across many instances in 26 yrs of Broadcast Consulting where a "purple cow" (an old Commission Staff term for something that could allow an exception to the standing rules) would exist. As far as I know, there has only been one instance of a waiver for minimum field for an AM facility granted, and only one instance of a Television "Duopoly" (overlap of the Grade B signal level by the same owner)ever being granted. Both were signed by a guy named Perryman... wonder who that guy is anyway?? <grin>! They both took monumental effort. Bottom line, armed with the proper guidelines (the Carey Report) and ensuing research (proof of your "Purple Cow") based on good engineering practice, a coordinating body has no reason not to grant the request. Unless, of course, they don't understand the engineering behind your pleading. If you tactfully educate them in your presentation of the facts, you should be able to work around that issue as well. While the coordinating guidelines in your area may be woefully antiquated, you have a much better chance of convincing these guys of the validity of your request, than trying to change the way they do business. Let me know if I can be of assistance in researching your pleadings.. 73 Mike Perryman www.k5jmp.us -----Original Message----- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] Behalf Of Kris Kirby Sent: Sunday, February 12, 2006 6:40 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] UHF Power On Sun, 12 Feb 2006, Paul Yonge wrote: > The policy of some repeater coordination councils to insist on a 100- > mile co-channel separation for UHF (and 120 miles for the lower- > frequency bands) regardless of the ERP seems like overkill to me. In > fairness, they do allow the consideration of terrain/ERP factors at > locations below 3000 feet AMSL (and more stringent requirements for > "very high profile" locations above the 3000-foot elevation). > > In the broadcast radio industry, we only worry about avoiding any > overlap of the 60 db protected contour with another co-channel > station's 40 db interference contour. Is it time to re-think the > coordination guidelines? Some areas may do this. It would not be a bad idea to do a terrain-based coordination factoring in AMSL and HAAT. It would be more important to have accurate fixes on the location of the entity being coordinated, with the understanding that said information would be protected. -- Kris Kirby, KE4AHR <[EMAIL PROTECTED]> "BIG BROTHER IS WATCHING YOU!" This message brought to you by the US Department of Homeland Security Yahoo! Groups Links Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
