How long for a broad spec. antenna?

[WL74]

I was wondering how long the CB antenna should be for the best broad spectrum transmission? I know that via the SWR, the lower freqs like longer antennas and the higher freqs like shorter antennas - so what length would be a good compromise for broad spectrum?

[linx]

Are you talking about trying to use a CB antenna for UHF frequencies? I'm trying to understand the question. The only thing I think of when you say "broadband spectrum" is "Analog TV". Like the "white space" that will be left free'd when analog tv switches to digital tv, and no one is using that bandspace.

[Circuit Breaker]

I think he meant to say wide banded antenna.

Since most of your activity will be on the normal 40, you're better off tuning the antenna for the best match on channel 19 or 20. That should get you the regular 40 and some coverage below and above. I'm a sideband person and most activity takes place on channel 35 and above so I don't have much use for the frequencies below channel 1. My current antenna - 102" whip with a quick disconnect - has a flat match from 26.000 MHz up to just over channel 40...so it is on the long side and needs to be trimmed so I can get coverage up to 10 meters.

[WL74]

Are you talking about trying to use a CB antenna for UHF frequencies? I'm trying to understand the question. The only thing I think of when you say "broadband spectrum" is "Analog TV". Like the "white space" that will be left free'd when analog tv switches to digital tv, and no one is using that bandspace.

LOL no ... hahaha I am not trying to make it any harder to understand then it is LOL. I am only talking about 26.965 to 27.405 CB bands. I am trying to figure out what is the ideal antenna for the entire Citizens Band

[Circuit Breaker]

Any antenna made for CB will be wide-banded enough to cover CB. Some are better than others but, regardless, if the antenna is made for CB it should cover the entire 40 channels.

[WL74]

I think he meant to say wide banded antenna.

Since most of your activity will be on the normal 40, you're better off tuning the antenna for the best match on channel 19 or 20. That should get you the regular 40 and some coverage below and above. I'm a sideband person and most activity takes place on channel 35 and above so I don't have much use for the frequencies below channel 1. My current antenna - 102" whip with a quick disconnect - has a flat match from 26.000 MHz up to just over channel 40...so it is on the long side and needs to be trimmed so I can get coverage up to 10 meters.

Oh ok thanks! So tuning on 27.185 would be the dead center channel to get the broad freqs then? ...And since you do most of your talking on the upper freqs - you want a shorter antenna correct?

[Circuit Breaker]

If you're only going to be talking on the regular 40 channels, set the SWR to be the lowest at 27.185 (channel 19). My antenna gives me coverage on all 40 channels. But since I also tend to venture above 40 occasionally, I wanted to make sure I had a better match above 40 than I have below 1.

[WL74]

Thanks! Now I am looking at an antenna with a 26-30mhz range - would that be better suited for higher freqs?

[linx]

Any antenna made for CB will be wide-banded enough to cover CB. Some are better than others but, regardless, if the antenna is made for CB it should cover the entire 40 channels.

Agreed. If you need to go further, you could always get an antenna tuner and let it tune the antenna for you.

[WL74]

Nice thanks! I think I will go with the Cobra HG A2000 though ... it has better consumer reports. How much are those antenna tuners?

['Doc]

All antennas have limits. Some have 'broader' limits than others, but that limit is still there. If you really want a 'broad spectrum' antenna, which typically means being able to use all of more than one band (typically what that 'spectrum' thingy implies), you can have such a thing. The 'catch' is that it won't be simple, orders of magnitude greater in co$t, and just about whatever length you can afford, almost. I just happen to have just finished mounting such an unlikely antenna on my truck. It's called a screw driver type antenna. It can cover everything between 6 meters and 80 meters at the punch of a button (and one whip exchange). It is huge, weighs a 'ton', is NOT easy to mount (or afford), ugly (eye of the beholder), and not the most efficient thing in the world. Would I recommend it for any single band use? Good grief, NO! But I'm getting lazier, and I use more than one band, so I got one. It replaced an antenna that you had to 'adjust manually, and was more efficient. That replaced antenna was also the 'pits' to mount, is big, ugly, a huge pain to tune the first time (for each band), and you had to stop to do that band changing. (It ain't easy/cheap to be this lazy and cheap, but somebody has to do it!)
- 'Doc

[linx]

Nice thanks! I think I will go with the Cobra HG A2000 though ... it has better consumer reports. How much are those antenna tuners?

Just FYI. I have a Cobra A2000 that I bought in like 2001. It's a pretty decent antenna. It's got a stiffer whip than like a Wislon, but is more sturdy too. I keep it on hand as the "buddy antenna" for friends that are wanting to get into it, so they can borrow it, or for family members going on trips that want to borrow an antenna. No complaints here.

Tuners cost big money. Unless you are wanting to go full HF, and get your General class ham license, then it doesn't seem like it would be a good investment. They work great, but they're just not for everyone.

[Circuit Breaker]

Since you're new to this...a tuner doesn't really tune your antenna. They should really be called impedance matchers. Tuners switch in (or out) the right amount of inductance and capacitance so that your radio sees a 50 ohm load and you get a decent SWR reading. However, if you were to take a reading between the tuner and the antenna, that bad match is still there. Depending on how great that mismatch is, a good portion of your power will be lost in the cable. The BEST place to put a tuner, if you were to use one, would be at the base of the antenna because it would reduce the amount of power lost in the cable. But that isn't always practical. The same thing also applies to wide-banded antennas. To get one to cover a wide band of frequencies, such as 26 to 30 MHz, requires some form of matching network or loading. That means some of your power is lost as heat...which means the antenna is less efficient. For the most part though, it isn't enough to worry about. In addition, most CB radios are tuned to give best performance on the regular 40 channels....if you go too far above or below that range and performance starts to degrade. Again, usually it isn't enough to snivel over.