Ham Antenna w/Limb Risers?

[Douglas]

Here is my ham antenna without limb risers...

 

[Idahoan]

Drivers side rear of vehicle... Problem solved.

 

[jerdog53]

Why not make the limb risers *the* antenna. VHF on the right and HF on the left

I was going to ask this question! Seems to me that these would be long enough with proper insulation could be very productive.


Sending elections from my electron sending device....

 

[Crom]

I was going to ask this question! Seems to me that these would be long enough with proper insulation could be very productive.


Sending elections from my electron sending device....

Vhf antenna for FM should be vertical, unless you like -20db loss.

 

[lysol]

I would probably put the CB antenna on the passenger side of the hood next to my FM antenna since they are separated quite well in the frequncy range and the HAM antenna on the driver's side. I was looking at motorized antenna mounts so that I could just flip a switch and the antenna would lower below the limb risers until I wanted them back up.

Though, it would probably be easier to just wait for the roof rack and place both antennas up there... too many choices... damn jeeps....

 

[lysol]

Do they make non-metal limb risers?

 

[Tennmogger]

How about building a limb riser that's a dipole on 2 m? Or even a 1/4 wave worked against ground? A piece of cable for a limb riser could be broken up to resonant length by egg insulators.

Bob WB4ETT

 

[lysol]

How about building a limb riser that's a dipole on 2 m? Or even a 1/4 wave worked against ground? A piece of cable for a limb riser could be broken up to resonant length by egg insulators.

Bob WB4ETT

Would that work with the antenna being close to a 45 degree angle towards the rear? I need to pick up a book on antenna concepts.

 

[jerdog53]

I don't see why it wouldn't work, I see this used for trail communications in simplex. Being at an angle like 45 degrees may not be optimal but functional none the less.

 

[lysol]

How close can an antenna get close to a limb riser without affecting the radiation pattern of an antenna? lets say the limb riser is a plastic coated steel line.

 

[Yuman Desert Rat]

Do they make non-metal limb risers?

I'm sure you could make your own. If you had access to some Kevlar cable that would be pretty tough?

 

[gary in ohio]

You would need to put some insulators on the limb risers but you could use it for a dipole on 2, 6, 10, and CB. Range would be limited but it wold be a nice rig2rig antenna. Then setup something higher at camp for longer range communications.

 

[Frdmskr]

Vhf antenna for FM should be vertical, unless you like -20db loss.

Not entirely true. If you are 90 degrees out of phase you can be down that much. However, if you are only 45 degrees out of phase you only loose 3db or half an s-unit. So yes, I have to ask, why not scrape a bit of the vinyl off and load it up. I'd think you could put an insulator or two and create a 2m dipole or a 6m dipole depending on length. Alternately, you could use a 108" whips bent back as a riser. Look at some military vehicles and some folks that try NVIS. Its not ideal, however, you are not trying to win a contest just chat car to car or back to camp/base.

 

[Crom]

Not entirely true. If you are 90 degrees out of phase you can be down that much. However, if you are only 45 degrees out of phase you only loose 3db or half an s-unit. So yes, I have to ask, why not scrape a bit of the vinyl off and load it up. I'd think you could put an insulator or two and create a 2m dipole or a 6m dipole depending on length. Alternately, you could use a 108" whips bent back as a riser. Look at some military vehicles and some folks that try NVIS. Its not ideal, however, you are not trying to win a contest just chat car to car or back to camp/base.

Good luck with that. I won't deny that if done correctly it would work--at least for some range, but why? It would be a lot more work and be very inefficient. Half the radiation would be into the sky and the other half pointed at your face in the cab. It sounds like a dumb idea to me. NVIS antennas operate at HF--NOT VHF, so entirely a different animal--not a good comparison at all, IMO.

 

[Frdmskr]

In ham radio why not is as good a reason as any to try it. Gotta confess a curiosity in how that experiment goes.


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