CB radio beginner

[scotty]

Ill be putting a kenmore 2 meter fm rig on the kawabunga as soon as i get the parts to repair the fairing

[Nerobro]

I woudlnt' worry about ground plane. You can easily buy antennas (dipoles) that are designed for use without a ground plane.

If you were me, you'd stick to a handheld unit, and "maybe'" an antenna attached to the rear fender.

I can't emphisize enough about not putting out big wattage when you're in such close proximity to the antenna. RF burns are NOT fun. (4-5 watts is about what I'd considder safe) You'd be amazed what you can do with just four watts in the CB band.

*looks at the 440 and 2m 1/4 wave antennas on the top of his car*

Just as a note. when recieving, you could stick the antenna in your mouth and it won't harm you. While transmitting... that's another story entirely.

And I must seccond the advice on tuning that antenna. Antennas are relitively cheap, and so are wire cutters ;-) Take him up on the offer of the SWR meter. IIRC you shoudl be tuning for channel 19.. (I "think" that's the middle of the band)

KB9WSA

[Anonymous]

I woudlnt' worry about ground plane. You can easily buy antennas (dipoles) that are designed for use without a ground plane.

KB9WSA

A full-sized dipole for CB frequencies is about 17 feet long. Not the most convenient length for a bike. I wonder if a loaded end-fed half wave with a matching network might perform well, but I don't think Nick's that interested in experimenting with antennas. (That's for hams like us.)

Nick - you said you're mostly interested in being able to hear the other riders when you're leading a group. If you don't plan to do any transmitting, just about any piece of ungrounded metal will do for an antenna at short range. In fact, there are hand-held receivers that are capable of picking up CB frequencies on a small rubber duck antenna. Here's an example:

http://www.universal-radio.com/catalog/widerxvr/0005.html

(Disclaimer: I used to work for this company, but no longer have any financial interest. There are other sources for radio equipment.)

You could slip one in a jacket pocket and use an earphone or small in-helmet speaker. Today's receivers have excellent sensitivity - for short range (i.e. a mile or two) work they'll make up for an inefficient antenna.

If you do eventually want to be able to talk back to the group, what Nero said about RF exposure is worth listening to. A 4 watt CB into a bike-mounted antenna should be safe for short, infrequent transmissions, but if you're going to use more power or talk more frequently, a bike isn't the place to do it. (Your kidneys may protest.)

Dave, WD8CIV

[Nerobro]

the rubber duckies that I used for my HT1000 were claimed to be a dipole. (hey, I really don't know, it's what motorolla claimed) But I think it was an 1/8wave. I'd assume you can get something simmilar for CB.

[Keith Winter]

Being a Ham Radio operator myself, if your going to use a ham radio you will need a licence. Also the only band that would be useable with respect to antenna size is 10 meters. The required antenna for this band is smaller than CB. If you and your freinds like radio's on your bike's, you should ditch the HF band's and all go to VHF or UHF. Both these band's are not subject to electrical noise, it's almost perfect compared to CB for noise, the licence requirements are far easier than HF and they have very effective squelch, unlike CB. Also the antenna's require far less ground plane and are 1/4 the size of CB, in most cases they are smaller than the antenna on your car. VHF and UHF are both line of sight bands and are more than enough for bike to bike talk. They also don't get clogged up with "skip", have VOX microphone's so you don't need to push to talk and are 1/3 the size of a CB making them the choice for limited room install's such as a bike. Also Ham VHF's will tune to government weather and road channels. If you are licenced you will also be able to use the repeater networks that ham VHF offer's, so you can make call's all over North America if you need to,and it's free, CB you can not. Also the tuning aspect of VHF is a lot easier than CB and they are not prone to mismatch of the antenna by near by objects, such as passing cars ect,ect that is inherant with the CB or any HF band. Also the ground plane is the "missing" part of the antenna. All radio's work on full wave length calculations, so if your antenna is 1/4 wave length, as is the case with most mobile units, the ground makes up the missing part of the antenna. Loaded antenna's fool the radio into thinking the antenna is longer than it really is. This is done electricaly with loading coils and sometimes capacitors as well. The ground plays a even bigger role in these units and they are very sensitive to near by objects. The reflection due to mis-match on these loaded antenna's is very high in some mobile hook ups and is not recommended for motorcycles. If you drive around and watch a SWR meter, as I have done many time's, you will see this. VHF is still the best choice for bike's.

[Anonymous]

the rubber duckies that I used for my HT1000 were claimed to be a dipole. (hey, I really don't know, it's what motorolla claimed) But I think it was an 1/8wave. I'd assume you can get something simmilar for CB.

Leave it to Mot to make a claim like that. (Grin) Most rubber duckies in commercial service are 1/4 wavelength whips coiled into a short space. They need a counterpoise of some sort (radials, car roof, or your arm) to come close to being able to radiate. In that case, they behave like a 1/2 wave dipole antenna.

Actually, for Nick's application one of those foot-long rubber ducks that come with the "emergency" CBs would probably work. I wouldn't recommend the magnet mount - it should be bolted on, just so it won't blow off and knock down half the ride group.

I've seen ads for so-called 1/2 wavelength antennas for handheld radios, but they'd need some sort of a matching circuit either built-in or in a separate box at the base. But they've all been for VHF use, not CB.

Dave

P.S. Nick, sorry for the information overload. Debating antennas is ham radio's version of the chain/shaft discussion. D.

[Nerobro]

I tend to believe motorollas claims. Becuase not all of their antennas are "dipoles"

If I were putting CB on a bike... I'd proablly just stick to a handheld unit.

[Anonymous]

I tend to believe motorollas claims. Becuase not all of their antennas are "dipoles"

I'm sorry bro - I was more harsh than I intended to be. I've seen Motorola advertising that was flashy and almost worthless when it came to specs, but their technical documentation is better than many.

If I were putting CB on a bike... I'd proablly just stick to a handheld unit.

Same here. I'm a gadget freak, but I can't think of a lot I want to add on to mine. I'll probably put a clock on the handlebar at some point, but beyond that I don't feel the need for much else.

If my wife talks me into getting that full-dress Gold Wing so she can ride in comfort with the portable TV and minibar in the back, I might end up mounting an HF/VHF radio up front. Or, more likely, I'll just stick an MP3 player in my pocket.

Dave

[Anonymous]

CB

I tend to believe motorollas claims. Becuase not all of their antennas are "dipoles"

If I were putting CB on a bike... I'd proablly just stick to a handheld unit.

There are motorcycle specific units out there. I have a J&M on my Concours that I've been very happy with.