CB antenna, Help me choose Options

[pknowles]

I want to get a CB antenna for my trip to Nationals this year. Right now I have a hand held CB with a 6" antenna mounted on the CB. I'm going to keep the hand held because from what I have read there is little performance difference between a hand held and a professional radio, other then tunability. The performance is in the antenna. I'm thinking about getting a magnetic mounted antenna that I can put on the roof of the truck.

Questions:
1. What have you guys used and what to you recommend?
2. I know a longer antenna should perform better then a short one for CB freqancies, but how tall can I go? My truck roof is about 6 feet 2" high off the ground.

I'm willing to spend $50 if I can get something good. If it makes a big difference in performance I can go a little more.

[John_D.]

Both of my handhelds came with short magnetic mount antennas. (couple of feet tall)

Putting it on the roof gives it a good flat metal bottom (ground plane) that's needed for a good signal, so you're way ahead right there. Also with it on top of the truck, it's higher than most of the near obstructions, so you're good there too. Definitely won't need a big whip antenna up there... (IMG:http://www.frrax.com/rrforum/style_emoticons/default/smile.gif)

Beyond that, you could always get a swr meter and tune the length, but unless you're going for distance records, that's probably overkill.

[pknowles]

What should I expect from different antennas? Will a name brand CB antenna perform a lot better then a $35 radio shack one. If I go cheap, I'm thinking about the Radio Shack 21-994. I know the longer the better, but I have no idea what is a "good" antenna is vs an "ok" antenna.

[BigEnos]

I have a through-glass (think 80's car phone) CB antenna that seems to work great. I didn't want to have wires draped all over my truck so I went with something that was sorta permanent but could be removed fairly easily. Seems to be fine so far. I think it was $20 and I'm pretty sure they sell them at Wal-Mart, though that's not where I got mine.

[trackbird]

Longer isn't always better. Each antenna has to be tuned to a wavelength (1/4 wave, 1/2 wave, 5/8 wave, etc). So, your choices of lengths will be defined by the wavelength of the frequency that you're using and the loading of the antenna. If you took a 5/8 wave antenna and stretched it to some random length, it would typically be worse and not better.

However, I'm a licensed amateur (ham) radio operator, so I'm about worthless when it comes to recommending specific CB antennas.

I can recommend a nice tri band HT for those who are licensed to use one...... (IMG:http://www.frrax.com/rrforum/style_emoticons/default/huh.gif)

[pknowles]

What kind of transmission and recieving range can I expect? Right now I have a tough time getting 1 mile.

[trackbird]

What kind of transmission and recieving range can I expect? Right now I have a tough time getting 1 mile.

What is the output rating of the radio (wattage?)?

For reference, from a hillside (to a hillside, with nothing in between, line of sight), we can get about 7 miles out of 50 milliwatts (.05 watts) out of a handheld (under perfect conditions though) and with 5 watts I could get to the mountain beside Martinsburg WV from turn 9 at Summit Point (probably 15-20 miles). This was on a ham handheld using a portable antenna (radio mounted). CB is a lower frequency and tends to go farther (for the same wattage) than what I was using (I was on 1.25 meters/220 mhz and CB is 11 meters/29 mhz in wavelength) and the range should be better with a proper antenna and reasonable wattage (10 watts should do well for you with a proper antenna).

[pknowles]

What is the output rating of the radio (wattage?)?

4 watts output. I'm assuming it is 4 watts as sent from the handheld and the actual wattage transmitted depends on the effencency of the antenna.

Also I've been reading that 4W is the FCC limit, but they state 4W almost if people using more then that. I have no experience in this type of stuff.

I did however figure out how to build a SWR meter.

[John_D.]

I did however figure out how to build a SWR meter.

Cool. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/smile.gif)

I think I used to have one, way back in the day... No idea where it ended up though.

[trackbird]

4 Watts on a proper antenna, on 29 mhz should get you an easy 4-5 miles. The problem beyond 4-5 miles is the curve of the earth. If you are fairly low to the ground, you start to get the plannet in the way of your signal. When I was at Summit Point, I was transmitting to a receiver that was on the side of a mountain. That helps a ton (and then some).

Of course CB's can "skip" when the atmospheric conditions are right and go a long way. Using a tower (40 feet) and a good directional antenna, Dad was talking to guys in Michigan from Martinsburg (20 miles from Summit Point). He was using 10 watts. This was on 6 meters (50 mhz), and again, lower frequencies can typically travel farther for the same wattage (but you'll not have the antenna he does on his home tower, or the height).

As with everything, there are lots of variables. I'd think 5 miles is a good minimum number, you may do better than that though.