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On Sun, 12 May 2013 20:36:26 -0400, "Ralph Mowery"
wrote: I was thinking there was a mobile antenna system that you mounted two antennas and had a switch box that phased them for differant directions. Don't believe it worked too well as the antennas were usually too close together. Chuckle. That's because the co-phasing harness combiner would produce a giant null in the fore and aft directions. The box had a 3 position switch, that selected antenna 1, 2, or both. The problem was that there was no way to use a real Wilkinson splitter with the switch, so the both position was simply both antennas in parallel. That didn't work. The the base station 'scanner' antenna was devoloped using 3 verticals in a triangle patern several feet apart. Seemed to work ok for what it was. It's still being sold and it actually works fairly well. It's just a VHF/UHF version of an HF "fan" antenna, where each band has its own dipole. Well, for the scanner antenna, a monopole. The stranger looking the antenna, the better is works (and sells). During that period of time, I think Antenna Specialists' made up much of the CB antenna sales. Yep. I wasn't involved in antenna design at the time, but I did meet with some of the designers. The RF part of the design was minimal. The aesthetics, cosmetics, packaging, and sales pitch were the major considerations. Only double the power,, many of the ones I knew ran 50 to 100 watts in the mobiles back in the 70's. It started with doubling the power, again for good reason caused by the power divider. Radios had such features on the schematic as "Don't short this resistor or you will transmit at illegal power levels". That would usually get the typical 23 channel CB up to about 12 watts in. Linears came later. Incidentally, in about 1979, I worked on a marine 2-30MHz HF SSB transmitter. The 150 watt power amplifier was my design. Sales of "replacement" power amplifiers were rather high until management found out what the dealers were doing with them. Oh well. During those years you could sell almost anything to the CB. Much like for the last number of years you can sell to the audio/hifi people. Best scam I know of is the wire going from the hifi to the wall socket. For about $ 120 you get 6 to 8 feet of 'special wire' Even if it was special that would not account for the wire going from the outlet to the breaker box and then to th epole transformer.. Got $10,000? http://www.amazon.com/Denon-AKDL1-Dedicated-Link-Cable/dp/B000I1X6PM There probably should be a law against this, but on the other hand, the purchase of such an overpriced cable is probably its own punishment. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
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