new mobile antenna idea

[ai4ep]

Remember back in the " cb craze " days when there were combination am / fm / cb antennas for your trusty vehicle ? We also know they did NOT work very well. that was about 25 years ago. Can there be made a combo am / fm / amateur antenna that is cowl - mounted or mounted wherever that particular model of vehicle has a normal antenna for vehicles made these days ? They could come out with a 6 meter version; a shorter 2 meter version, and an even shorter 440 version, or some how make one antenna that would work on all 4 bands for those with multi - band rigs ! They would have to have in the coupling box the capacity to hold 50 watts at least ( compared to the cb models that were for 4 watts ), and price would not have to be that high for the common folk to be able to buy one. ..... this idea may have already been tried by Cushcraft, Hustler, and other companies and gave up on the idea, but you never know, this might be a good idea if it got to the right folks . http://www.qrz.com/iB_html/non-cgi/emoticons/smile.gif kd4amg

[AG3Y]

Back in those days, the primary mode of broadcast radio was the AM band , .5 to 1.6 Mhz and CB was supposed to only be 5 watts at 27 Mhz. Not saying that there weren't some more powerful setups, but I really seriously doubt that they would have tried to couple their rigs into a broadcast band hybred!

Thus under normal circumstances, it was pretty easy to keep the energy from the one radio from getting into the other radio.

Now days, the primary mode of broadcast radio is 88-108 Mhz, and that is fairly close to the 2 meter ham band, if you consider the one frequency as a percentage of the other.

That, and the fact that the power is a fair amount higher for typical VHF/UHF rigs makes it a pretty problematic situation. I would be afraid of a lot of interaction, which would not be good for either radio!

I suspect that if it were worthwhile, some company would have already come out with one. But of course, I could be wrong ! My 2Cents worth

73 from Jim AG3Y

[KF4ZHL]

It could be done. It would be costly though. You would need a duplexer or RF filter of some sort for the commercial radio. You'd need a switch for the other transceivers. I'm not sure where you's get this. Antenna switches are generally designed to connect a single radio to multiple antennas, not vice-versa. I guess if you hooked it up in reverse it would still work. You also need a method of tuning the antenna. An auto tuner at the antenna base probably would work best. I haven't ever seen these designed for anything but HF.

At best, it would probably significantly compromise the performance of all devices attached.