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Author Message   holl_ands Advanced Member Username: Holl_ands Post Number: 363 Registered: 06-2004 Rating: N/A Votes: 0 Posted on Tuesday, March 22, 2005 - 01:22 am:    DTV PROPAGATION PREDICTION (PPP No. 5): RADIO MOBILE SETUP INSTRUCTIONS. I've checked antennaweb.org antenna recommendations for about half-a-dozen FnznFam. Invariably, the outlook wasn't very good. Except for Winchester, CA, only two to four DTV stations for Scripps Ranch, PQ, N. County Fair and Escondido. So, after hearing forum comments about it being "too conservative", I looked for better methods. Especially methods that give more insight into the underlying models, assumptions and effect of user parameters. The FCC uses a version of the Longley-Rice Irregular Terrain Model (ITM) to calculate required power for a given coverage area and to help prevent interference between stations. Although I started to configure the (free) NTIA version of ITM, I ran across a program that used the ITM model, but had a much better user interface....and LOTS OF PRETTY MAPS!!! I've been building up the database with SD/LA specific files (available via private message). Radio Mobile can be downloaded for free from fol. site: http://www.cplus.org/rmw/english1.html Unzip the "helper" files into the same directory as Radio Mobile. Follow "How To" directions to download SRTM-1 files into a mapdata directory (N32W116 to N34W120). (Virgina Emerg Network works, NASA site is painful). I replaced two of the SRTM-1 files with the fol. 90m resolution SRTM-3 files due to missing data: N32W116 and N32W117. Also print the user documentation found in the "How To" links. Radio Mobile is very easy for a novice to setup and use....the hard part may be interpretation... Use "Map Properties" to display map database by linking SRTM data source to mapdata directory. The map scale is controlled by the "Height" field, since the "Width" field is not working. For LA to TJ: Height = 200 km, LAT = 33.35, LONG = -117.3 "Picture Properties" allows the user to select several different B/W, Color and Rainbow displays. I use Rainbow with Absolute Scale settings tailored to provide realistic colors. If Radio Mobile can't find a map or satellite image overlay file on disk, it will automatically try to locate it on the Internet. Once you're set up, you can tell it to quit nagging you about missing files you don't need. (Message edited by holl_ands on March 22, 2005)