Mike, You already know the answer- it's by *measuring* the signal strength. Even high-end propagation programs like ComStudy, which I use, can only estimate what the signal strength should be, based upon known topography. The "fly in the ointment" is the fact that the real world does not agree with the digital elevation models or the land coverage models. My expensive software, and the free Radio Mobile software, share the same deficiency: The real world does not agree with the model! Trees grow, and buildings are erected, and both will attenuate the signal and affect the coverage. To be blunt, only a fool will embrace the coverage plots without verification.
I use a really nifty tool made by Berkeley Varitronics, known as the "Coyote." It is basically a recording signal strength meter. The Coyote unit contains both a GPS receiver to continuously determine and record the position, date, and time, and a calibrated receiver to provide a continuous record of the signal strength received. I simply drive the perimeter of the promised coverage area, and the proof is in the signal plots. Even in the best-planned systems, there will be dead spots. Even if such dead spots cannot be eliminated, it is valuable information to know where they are. There are some well-known radio manufacturers who have made fantastic promises about coverage when bidding on a contract, who later had to upgrade their systems at a huge cost, because someone actually used a mobile signal strength meter to check on the claims. That company wound up making only a paltry profit after they were forced to meet their claims. 73, Eric Lemmon WB6FLY -----Original Message----- From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of Mike Besemer (WM4B) Sent: Thursday, January 03, 2008 2:17 PM To: [email protected] Subject: [Repeater-Builder] Measuring Coverage Area What's the most accurate down-and-dirty method of measuring the footprint of a repeater's receiver coverage? I know. the whole question sounds like an oxymoron, but inquiring minds want to know. de WM4B Mike Kathleen, GA
