CompuServe Messages

Hi, John… >>>Tell me more about the Paraflector. Manufacturered by SCALA Electronic Corp in Medford, Oregon. The phone number I have for them is 503-779-6500. The Paraflector is a ruggedly built 900 MHz designed for a professional in communications and is fairly large for what is thought of as a typical 900 MHz antenna. The front/back ratio is excellent as is the forward gain. Oh, yes…the forward lobe of the antenna is narrow and well defined, excellent for rejection of unwanted signals. The cost reflect the quality of construction – several hundred dollars each. ..and it will definitely look high-tech on the top of your old brick office building <g>. The contact I use at SCALA is/was Dan Fowler. >>>…and a range up to 20 miles using supplied whip antennas. I believe the active words here, John, are "up to 20 miles". <g> Several hundred feet falls within that "up to 20 miles" range. I have a handheld 440 transceiver with a "duckie" whip antenna on it that will talk about 25 miles from my front door too…only the other end is at 4,500 feet on a mountain top with a +9dB gain omni antenna. The problem with statements such as this…and I have seen the glossy spec sheet you have…is anyone with any perception of how close the line-of-sight horizon actually is and the awareness that 900 MHz is essentially visual line of sight communications (almost deemed as a microwave frequency) tend to discount their claims. With the proper overall radio system design and consideration given to antenna height, gain, and directivity, 20 miles is well within the limits of a system gain of 135 dB. If a radio system is the best choice for a communications channel, then many of the "wireless" products on the market will fill that need. But I find it very frustrating to have a spec sheet like this one presented to me because most of the time I would have to say, "Yes, but…" As an example of what I mean by line-of-sight…I assisted with the troubleshooting of a wireless system based upon product that shall remain nameless because the ends of the wireless system wouldn't talk. The application was between two buildings about 3/4 mile apart separated by a rise in the ground. A line-of-sight path did not exist. Each end of the wireless system had an outdoor yagi antenna about 20' above ground level with a 11 dBi gain and fed with 1/2" helix semi-rigid very low loss coax. After all these RF enhancements, about 10% availability was the best we could obtain. We checked the RF output of the unit and it was at spec with proper modulation…and when the two units were brought within visual line of sight, provided a solid reliable circuit. (We did this last just to verify that the system DID actually work with a proper RF path.) BTW, the system still does not function. You will be very satisfied with any SCALA antenna, John. …JJ Read action !