The predicted coverage for the system presented on this page is for reference only. It has been created using a combination of technical facts and known system performance.
Below we will present two types of coverage area plots that represent the predicated normal coverage area that a mobile (35 watt average) station using the typical 5/8 wave UHF mobile antenna can expect to experience using the repeater system when in the clear. We will also provide predicted coverage area for a hand held (5 watt) user with a 1/4 wave rubber duckie antenna.
The plots depicted below will be of two types, those that are created using Digital Elevation data taking into account antenna height above average terrain of the repeater system antenna and those that using Tiger data for mapping that take into account the system EIRP and antenna height above Ground and Sea Level for distance but not terrain characteristics.
The view from the top of the tower is quite spectacular as can be seen in the following photo, however, what one can see with the naked eye is not the line of sight of the repeater station.
Terrain Analysis Line-Of-Sight (LOS) Plots:
The LOS Terrain Analysis map images for the 443 repeater below were created using the Sight It!™ LOS Calcuator™ MS-Windows terrain analysis software developed by N2CKH. The software is quite a powerful Terrain Analysis tool that is geared for use in Amateur Radio. In the image below contains many peices of data, the colors for each elevation bin have been set in the software with Black as sea level and Blue for 1 to 40 meters in elevation, we have also turned on the Cities, County (white line) and State (Red line) boundry outlines as well as maiden head grid square display overlay layers for a point of reference and dropped the locations for the QTH of N2CKH and K2DE by entering the repsective coordinates.
To continue, LOS coverage does NOT take into account foilage, man made obstructions or even the antenna pattern of the repeater site. Also, due to the nature of the 1 degree DEMs from the USGS and the fact that Sight It!™ you do not see the actual 360 degree sweep as the physical location of the 443 repeater is in the lower right quadrangle of the DEM, on the coast line thus no DEM data is available for that area as it is the Atlantic Ocean at sea level.
To create these plots the software makes use of 1 degree by 1 degree Digital Eleveation data distributed on the Internet free by the U.S. Geological Survey (USGS). This date is called Digital Elevation Model (DEM) data, and is provided in 1 degree, 30 minute, 15 minute and 7.5 minute coverage for most areas of the U.S. Many Amateurs are familiar with 7.5 minute topographical maps for determining their exact coordinates and elevations that have been involved in satellite communications or installation of a repeater system.
In the image below we have choosen different color combinations for the elevation bins than used in the previous image. Note that the brighter the color, the higher the elevation bin it represents. All the areas that have the lime green color within the circle overlaying the map are LOS from the repeater site with respect to average terrain. Again this does not take into account foilage or man made structures or antenna pattern, which could atcually effect both LOS and Radio LOS (R.LOS) to the horizon.
However, for those that use the repeater system from their mobile and with their handhelds, this view gives you a much better idea of the coverage of the repeater in those times of poor performance. Take a look at the lime green covering due North of the repeater site, the most northern LOS to the side of three hills in the Holmdel, Matawan area, that one is the famous Telegraph Hill just off of Route 34. As one can see the other side of these hills block the signal significantly up close to the hills and in many case for some distance beyond. If you look North toward Staten Island New York, you will see that rise in elevation causes the south side of a lare area to be LOS to 443 but the same area complete obstructs 443 beond that point.
The image shows the Line of Sight (LOS) coverage as would be seen from the top of the supporting tower for the AERIALS 443 70cm repeater located in the Ocean Township area, it has a height above ground level (HAGL) of almost 200 feet and is about 300 feet above sea level (HASL). However, there are many areas within a 70km radius of of the system that it does not have LOS to, thus those areas are potential poor areas for mobile and handheld communications. It can readily be seen that parts of both Staten Island and Long Island are served quite well, it is just too bad that the system is not over in the Howell or Lakewood area with same HASL.
Predicated Coverage Area Plots:
The images below were created using Tiger Mapping Data. They depict general predicted coverage radius within the range of the repeater system.
The image below shows a radius of 70km ( miles) in Blue which is the prdicted maximum good mobile (35 watt 5/8 wave antenna) coverage when in the clear. It does not mean that a user can not operate farther while mobile when in the clear in a high terrain location of with a better antenna/power out combination.
The coverage area for a base station will likely extend to a maximum of 150km for non-enhance band conditions or more depending in that station antenna system, power level and height above average terrain.
If one was to correlate to the Terrain Anaysis plots above, it can be seen that centain high spots within the 70km radius actually offer line of sight (LOS) to the repeater antenna (average terrain only) and at those spots it should one attempt access the results would be much better then the general area surrounding them.
The image below shows a maximum radius of 70km as above for mobile, however we have added smaller radius plots for 10, 15, 20 and 25km coverage from the repeater sight for predicted hand held operation when outdoors in the clear.
The purple 10km radius is predicted to yield solid hand held coverge under most all power levels outdoors. It will also provide excellent hand held coverage at 2-5 watt levels in most residential indoor locations.
Moving further out to 15km (between Purple and Green) outdoor performance in most locations with an hand held will start to require power levels of at least 1 watt from most locations with indoor performance dropping off considerably.
Moving further out to 20km (between Green and Red) outdoor performance will depend on being in the clear and using 3-5 watt power levels. Indoor performance will likely be recieve only with very few stations actually accessing the repeater.
Moving further out to 25km (between Red and Black) outdoor performance will likely provide for receive from most locations in the clear, access will require a full 5 watts and be location dependant.
Beyond 25km the reception and accessing via a hand held will be dependant on location and the use of 5 watts. The higher and the more unobstructed the path the more likely one will achieve success.
From past experience when the system was in top performing condition working it outside with a Yaesu FT-470 HT and Diamond RH-77 whip antenna and 5 watts yielding excellent results out to the 20km region and I (N2CKH) was even able to reliably work the system from my parents backyard in Sayreville (25km) down the hill from Route 9 and Ernston road. At the top of the hill around the White Castle only 1 watt was needed as it was much higher ground.
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