serpentine mudflap VHF antenna

[olly hondro]

There is a company that makes them, embedded in mudflaps with an RF connector. I imagine one could come up with a poor man's version, sandwiched between two flaps. Your thoughts ?

 

[olly hondro]

Green Wave Scientific. Will explore the patent offfice website to see what info is available. I like the idea of a stealthy antenna.

 

[ke5eua]

Can't be to effective and if you are expecting to use it on cb forget about it.

I would image it is a unity gain type antenna.

 

[glassk]

http://www.greenwavescientific.com/datasheets/Datasheet VHF antenna Mudflap Antennas.pdf

 

[ke5eua]

I love how it states 20-500 MHz but the vswr graph even shows anything below 90 MHz is over 3:1

I like the idea behind it but without a matching unit to accompany it your just melting the ice off the mudflap.

With the antenna so low to the ground the radiation pattern wouldn't be effective as a whip.

 

[ke5eua]

I do like the video of the salt water antenna system.

 

[olly hondro]

My thoughts are along the lines of driving to the top of a hill then facing the rear of the vehicle toward where I want to communicate. Not on a regular basis, rather, for emergency or relay comms.

I am really am trying to keep the outside of my vehicle as clean as possible (no roof rack, fuel cans, uneccessary lighting) so do not want the antenna farm look. I guess I will just go with handhelds to solve that problem. I need mudflaps anyway, seems nice to have dual functionality wherever possible.

 

[ke5eua]

My thoughts are along the lines of driving to the top of a hill then facing the rear of the vehicle toward where I want to communicate. Not on a regular basis, rather, for emergency or relay comms.

I am really am trying to keep the outside of my vehicle as clean as possible (no roof rack, fuel cans, uneccessary lighting) so do not want the antenna farm look. I guess I will just go with handhelds to solve that problem. I need mudflaps anyway, seems nice to have dual functionality wherever possible.

I understand the purpose, and need. True hams drill holes, lol

 

[tim292stro]

I tend to agree with Mike/KE5EUA. The radiation pattern they put in the datasheet is a free-space radiation pattern in a semi-anechoic chamber - not mounted to a vehicle, and definitely not mounted to a vehicle with your configuration (datasheets illustrate the ideal capabilities of the antenna before the "system" is considered). Vehicles make a terrible ground-plane due to the various body panels, rubber isolators, rust/corrosion, and the noise created by the vehicle's own electrical system - then take into account that the vehicle is mostly isolated from the ground by the tires making the truck a capacitive ground (virtual ground).

If you're already talking about parking your truck for emergency comms, why not get a telescoping fiberglass flagpole and hang a piece of wire from it and make yourself a dipole? The same pole could be used to make a ground plane antenna (4 ground radials). You can keep your radio in the truck if you want and put an N-connector bulkhead fitting somewhere out of sight (like in a rear fender-well) and keep a cover plug on it when not in use (further trick would be to put a dummy N-female connector with a micro-switch in the TX circuit of the radio - so you have to take off the cap, put in on the dummy fitting before you can transmit -should save a power stage or two).

If you just don't want it visible when you don't need it, try an NMO antenna mount through the roof, then put a cap on it when you don't have the whip attached.