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Dual 102 whips

A 1/4 wave for the FM broadcast band would be something on the order of about 2.5 feet. Probably not much different than you have now as far as length goes. Probably any of the commercially made antennas for car radios would work just dandy, but who knows what/how that would compare to what you have now?
A typical dual antenna system's only benefit is that it offers 'gain' in some direction(s), but not in others. The biggy would be keeping your car/truck pointed in the right direction! While that 'gain' would be nice, an omnidirectional mobile antenna is much easier to live with than a directional one. Don't get fixated on the 'gain' thingy.
- 'Doc
 
NJCM said:
Could anyone give me a product list? Since a cb antenna isn't adequate for an fm radio. What is? I want the same length antennas if possible, I could run 3 antennas one for the radio and 2 for the cb, but would 2 whips for my cb be beneficial to me? Thanks for the quick replys!
Click to expand...

2 whips for the cb will only really be beneficial if you can get them spaced at least a 1/4 wave apart (approx 9ft) less than that then the benefit is seriously minimised and any gain would be offset by radiation pattern distortion, you'd be as well using one in a central location (ideally roof mounted) for an omni directional radiation pattern, the other problem you would encounter with 2 whips is co phasing them,as the antennas would be parallel to each other you would have to use a 75 ohm co phase harness to get them matched, using a dummy load on one as you match the other and vice versa. not for the feint hearted if you ain't sure how to do it.

as for the radio antenna, any car accesory shop should sell antennas suitable for car radios, as the length is proportionate to frequency then the chances of getting car stereo antennas the same size as a cb antenna is unlikely, but that doesn't mean it isn't as efficient as a cb antenna on its own frequency of use.

for example a 1/4 wave ham radio antenna for 2m (approx 146 mhz) is roughly 50 cm long but its just as efficient as a 9 ft long cb 1/4 wave when its used on 2m band.
 
Marconi said:
Robb, does the implications of the various patterns suggest gain? If so, how much in DB's is noted?

Too bad he didn't give us a single omni for the comparisons.
Click to expand...

the hy gain page on cb tricks has an interesting report on phased vertical clr/gclr antennas.bottom file of the list:

CBTricks.com Hy-gain Electronics Corp. Antennas Index

you have to bear in mind though that unless the phasing is made switchable, gain in one direction will cause loss in another, you don't get nothing for nothing.same applies to mobile antennas. thats why generally speaking on a vehicle one centrally mounted 1/4 wave is about the best allround scenario going.

truckers may benefit from phased arrays to give extra distance ahead, but it comes at the cost of less distance to the back or/and sides.
 
To paraphrase Jazz; don't get your heart set on having two whips if you really want your CB to perform well . . .

UNLESS these antennas are 9 ft apart; they will just cancel signals out of the transmit. So no one here is really going to support that idea - IMO.

Diesel rig drivers can run dual antennas. But that's because the antennas are 9 ft apart! They also transmit bi-directionally. It works for them. It would look awkward to make a dual antenna system work on a pickup truck. Having one antenna on each bumper might work; but it won't work well - because the antennas are below the vehicle's sheet metal.

Antennas - when transmitting - are compromised when placed less than the highest point of the vehicle. Why? Because if any part of the antenna is below the sheet metal - it will skew the radiation pattern (very important). SO, by running the antenna from the highest point (like a magnet mount antenna on the roof) there is no real loss of antenna transmit propagation/pattern.

If you looked at the link I posted above; you would see that is the case in fact.

You might like the LOOK of the dual whips. The guys doing it on their pickup trucks are doing it for the aesthetics - for 'looks'; but not for function. But know this - the guys that do it are POSERS . . .

There . . . I said it . . .
:oops:

EDIT: If you intend to run two steel whip antennas - one used for the CB and the other for the FM radio - that is 'another can of worms'. Having these two same antennas so close together will interact unfavorably. If one is to be used for the FM radio; I think it is the wrong impedance. A 1/4 wave steel whip is 75 ohms. Most FM radio receivers need 300 ohms impedance. Not a match . . . Could be wrong about that one - tho.:love:
 
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Robb said:
To paraphrase Jazz; don't get your heart set on having two whips if you really want your CB to perform well . . .

UNLESS these antennas are 9 ft apart; they will just cancel signals out of the transmit. So no one here is really going to support that idea - IMO.

Diesel rig drivers can run dual antennas. But that's because the antennas are 9 ft apart! They also transmit bi-directionally. It works for them. It would look awkward to make a dual antenna system work on a pickup truck. Having one antenna on each bumper might work; but it won't work well - because the antennas are below the vehicle's sheet metal.

Antennas - when transmitting - are compromised when placed less than the highest point of the vehicle. Why? Because if any part of the antenna is below the sheet metal - it will skew the radiation pattern (very important). SO, by running the antenna from the highest point (like a magnet mount antenna on the roof) there is no real loss of antenna transmit propagation/pattern.

If you looked at the link I posted above; you would see that is the case in fact.

You might like the LOOK of the dual whips. The guys doing it on their pickup trucks are doing it for the aesthetics - for 'looks'; but not for function. But know this - the guys that do it are POSERS . . .

There . . . I said it . . .
:oops:

EDIT: If you intend to run two steel whip antennas - one used for the CB and the other for the FM radio - that is 'another can of worms'. Having these two same antennas so close together will interact unfavorably. If one is to be used for the FM radio; I think it is the wrong impedance. A 1/4 wave steel whip is 75 ohms. Most FM radio receivers need 300 ohms impedance. Not a match . . . Could be wrong about that one - tho.:love:
Click to expand...

So there is no reason to run one 102 whip for the radio and for the cb because the one for the radio would counteract the cb whip?
 
Ok since my dual whip idea is kinda blown out of the water, what would be the best thing for me to do, I don't want to mount them anywhere but my bed or rear bumper. Magnet or bolt ons do not matter to me, Any thing will help me out. Thank y'all again!
 
NJCM said:
Ok since my dual whip idea is kinda blown out of the water, what would be the best thing for me to do, I don't want to mount them anywhere but my bed or rear bumper. Magnet or bolt ons do not matter to me, Any thing will help me out. Thank y'all again!
Click to expand...

Best performance is with a "generic" 102 inch steel whip and a tri-magnet mount.
~$75?

Next best is the "Predator 10k" with the same tri-magnet mount.
~$125?

Third place goes to the "Sirio 4000 Performer" that comes with its own magnet mount.
~$110?

Fourth place goes to the Wilson 1000 or Wilson 5000 magnet mount antenna.
~$75-$85

For best results, mount any of them on the vehicle's top/center roof. Shipping charges extra . . .
 
Because the truck has a brand new paint job there's no way i want to take a chance of scratching it, so that's why said only on the bed.
Could I run dual whips if they weren't 102s? or 2 fiberglass ones maybe?
 
Unless they are mounted 9 ft apart, it will work worse than a single antenna.

Makes no difference if they are 5 ft fiberglass antennas or 8 ft steel ones.

Besides, some of the pictures shows them mounted by DRILLING HOLES to attach the mounting brackets.

I'm sure ANY antenna will work; it is just a question of how well you want/need it to work.

The antenna choice you make - and where you mount it - is pivotal . . .
 
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NJCM said:
Ok since my dual whip idea is kinda blown out of the water, what would be the best thing for me to do, I don't want to mount them anywhere but my bed or rear bumper. Magnet or bolt ons do not matter to me, Any thing will help me out. Thank y'all again!
Click to expand...
If you want performance, just drill a 5/8 hole in your roof and mount a Wilson there. Pop the center dome light out and remove the "B" pillar. Fish the coax down to the floor, under the drivers seat, up under the center console and your done. Very clean install with about the best all around performance as your gonna get ............ short of installing a 1/4 wave whip there.

I know you said you didn't want to, but most people who fiddle fart around with other mounting options end up here anyway, and then they kick themselves for not doing it sooner.
NJCM said:
Because the truck has a brand new paint job there's no way i want to take a chance of scratching it, so that's why said only on the bed.
Could I run dual whips if they weren't 102s? or 2 fiberglass ones maybe?
Click to expand...

The very best thing to do with a new truck, or even an older one with a new paint job, is to throw a concrete block into the bed and get the first scratch/ding out of the way.

EDIT__________
Besides, since we are talking about a dually pickup, anything mounted to the rear bumper or bed rails will be in the way eventually.
 
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Its a k10 and is srw not a dually. I don't mind drilling wholes in the bed, thats not the problem, i refuse to do it on the roof though.:glare:
 

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