Is it possible to have (too much) antenna?

The amount of power an antenna will handle has nothing to do with the receive or transmit capability of the antenna. The SWR and the ground of the antenna system has more to with its recieve and transmit capability of the antenna. As long as the SWR is good then the system should work well. There are allot of people that believe the bigger the antenna the better it will work. This in some ways is true. But as a general rule as long as it is matched good it should work well. Some antenna systems work better in some application than others but that is a matter of trial and error for each individual application.

 

The response from the first person to respond flat nailed it. An antenna that can handle high wattage is necessary for a cb radio setup that uses an amplifier. While you can use it with a stock-out-of-the box radio, the antenna that can handle high watts is gross overkill and not cost effective at all.
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If you intend on installing an amplifier to your setup at sometime, then it makes sense. And let me be very clear, I DO NOT in any way support the use of amplifiers. I personally would advise you to spend your money more appropriately. For example: how are the speakers that are hooked up to the AM/FM radio?
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The legal limit for a cb radio is 4 watts. With a legal maximum limit of 4 watts going into an antenna, there is absolutely no way in [bleep] for the antenna to output anything more than 4 watts. Anbody tells you anything different don't believe them.

 

I concur with my colleagues above. A well matched antenna over a suitable ground will talk out *and hear* better than a random antenna system with 200 watts.
The only way in which bigger is better that I'm aware of, everything else being equal, is that a taller antenna will be more efficient than a shorter antenna. Keep apples with apples, though; a 6-ft Shakespeare will likely outperform a 2-ft Shakespeare from the same series, same loading style, etc.
Hams & public safety folks often use short, loaded antennas on their handhelds for convenience, i.e., on 150 MHz, a full sized portable antenna would be about 18 inches long. Hard to carry on one's hip, so most folks have rubber duckies around 6 inches long.
At 450 MHz, a full length antenna is about 6 inches; a lot of cops put 2-inch stubby duckies on to save space on their Batman belts.
In both cases, the shorter antennas do not perform as well (as far away) as their full length counterparts. But in a system where the reduced range is enough, they're fine.
Around town, I use either a 2-ft Barjan fiberglass antenna on my roof for CB so I can park in the garage at the shop and the house. On road trips, I replace the Barjan with a Maxrad base loaded steel whip (about 45 inches long), or a 102" with spring on the rear corner of the van, when I need the greatest range. I've been able to confirm the relative performances on an antenna test range. So the most convenient antenna for me, while the worst performer, is OK for most of what I do.
And high power? The Barjan is rated for, I think, 100 watts; the Maxrad, 200; and the 102", at least 2kw. Know how much I run?
4 watts.
-- Handlebar --

 

The 5000 watts rating they put on those antennas just means that's what they'll handle if you decide to run "heat". Otherwise if you're not running any major power, a 5K antenna is as good as a 2k antenna. That's why my mobile mount is a Wilson 1k instead of the Wilson 5k everyone tells me is "supposed to be better". It's not doing me any good only running 4 watts of power. Plus they're both the same size whip. They both work the same, and I saved $$.

HOWEVER, your antenna "height" DOES play a role in how far you can talk in addition to a low SWR, and how far you can hear.

I'm interested in knowing how you're getting an honest 40 watts from a Cobra 19 Ultra IV, unless you're just running a linear.

 

Me too! I would believe swinging 20.

 

GASP 5,000 watts I did MOONBOUNCE with 900

 

The 2sc2078 final is nominally rated for 4 watts output; it's absolute maximum is 10 watts, and that isn't for long.
Of course, if it's been screwdrivered nearly to death, including spreading out the coils in the output matching network so that it puts out a bunch of harmonics, and is being read by a....ummmm.... less-than-accurately-calibrated wattmeter, and if the needle on the wattmeter developed enough momentum to keep swinging upwards long after the signal had ceased to be there.....
Nah, I'm not going for 40 watts, either.
Wonder what that poor thing looks like on a 'scope?
<sigh>
-- Handlebar --

 

I used a predator 10k good antenna but when I hooked up my 102" steel whip the performance, rec & transmit was way much better & both were at 1.5 on the swr.My own opinion the antenna whether cheap 102" $20 or expensive predator 10k $65 makes all the difference....

 

Hey handlebar, you know they call those types of meters the feel good meters. Most any truck stop CB shop has one. It's one of the tricks of the trade to con unknowing truck drivers into spending their hard earned cash thinking they're getting a big talking radio that really just ends up splattering all over the band.