|
On-The-Go Radio
A Look At Our Prototypical FRS Station And
Special Recognition by Alan Dixon, N3HOE / WPUC720 / KST8678 |
Photo A. Our “small base station” antenna setup. (All photos courtesy N3HOE.) |
||
|
|
Last month we began our description of how to assemble your very own “higher-power” FRS monitoring and operating station. Our prototype FRS home-base station is actually a GMRS small base station operating on the GMRS interstitial or “splinter” channels, as we had previously noted. These same channels are actually those used by Family Radio Service handhelds, on Channels 1 through 7, and you will need an easy-to-get GMRS license, of course.. Let’s start from the top. I assembled the prototype station described here for about $200. At this relatively low cost there is little reason why REACT monitors and other communications volunteers desiring to monitor and respond to FRS Channel 1 shouldn’t have a functional and powerful GMRS small base station with which to do so. Photo A shows the antenna setup. Our antenna sits atop two 10-foot sections of common TV antenna mounting poles, available at RadioShack, mounted at ground level. This puts our antenna mount exactly 20 feet above ground. Had this been a freestanding antenna assembly, the distance to the tip of the approximately three-foot-long antenna would have to have been limited to a total of 20 feet. (Caution: Twenty feet of antenna pole(s) cannot safely support anything as a freestanding assembly, however.) Our antenna pole assembly is securely mounted to a house, though, so this antenna could legally extend 20 feet above the roofline, to the antenna tip. But let’s say, for example, that the negotiated deed restrictions on our “test” home limit the tip of the antenna from extending more than 10 feet above the roofline. Our antenna now must stop just short of that height. Considering that we have made our antenna at least 20 feet above ground level, we have it placed within an optimum height for our purposes here. Though difficult to see in this photo, a ground wire extends down the pole from the antenna, and then goes to an eight-foot grounding rod. In Photo B, we see our RG-8 feedline (along with a parallel coaxial feedline for HF) terminating into a gas-discharge-type static discharge “block.” (You should be able to get one of these at the same place you got your antenna.) A ground wire runs from the ground terminal on the static discharge unit to an eight-foot ground rod, just like the ground wire at the antenna. According to the National Electrical Code, ground wires must be at least #8 (8-gauge) aluminum or #10 copper, and need not be insulated (ANSI/NFPA 70-1996 NEC §810-21(b), (h)). Check with your local code enforcement authority for updates and to see if more stringent codes apply in your locality. |
||
