VHF antenna angles

[Four Suns]

I've noticed this more and more up here on the bay. People seem to mount their antennas at an angle to match the angle of the hard top, or struts, or anything to try and make it "look good"

That's a Sea Ray 450 behind me here in Cambridge but there are several other Sea Rays at the dock that have done the same. My limited understanding of VHF (and most other) omni directional antennas is the signal radiates perpendicular to the antenna hence you want the straight up and down and as high as you can get them. Like the boat next to the Sea Ray. Do you all communicate with aliens up here on the north bay and is that why you angle them back or am I missing something? Doesn't this angle back thing destroy the signal forward and backward of the boat?

I also like the extender on the GPS to put the GPS antenna right in the radar beam as well as the hailing loud speaker angled down at the helm. Guess the captain can really hear him/herself when yelling over the thing. Maybe his kids sit behind him and that is a way to make them listen.

 

[ImpulseIII]

May not be practical or operationally functional, but it does make the boat look faster!! Kind of like "spinners" on hubcaps or fender skirts on cars.....Nah, you are all too young to remember that "cool" stuff!

 

[fwebster]

Gary,

I'm suprised at you....you have completely missed the point.

The 450EB owner just wants to commune with nature by blasting the fish right under his transom with his VHF signal........ wonder if they speak the same language?

 

[SearayPaul]

Antennas should be straight up and down for the best propagation of your signal. The higher the frequency the more important this becomes. This is the theory.

In practicle application there are other factors that influence the way the radio wave is disipated across the air. The radio wave energizes the antenna which causes a harmonic to be induced which spreads the signal out in concentric circles with the antenna being the center of the rings. These rings are in perpetual motion until the recieving antenna picks up the signal where it is amplified by your radio. Sensitivity of your radio and the gain of your antenna will determine if you recieve the signal since the wave was transmitted in an infinal plan.

The arch in this picture is going to do more to alter the signal than the angle of the antenna. The arch will either act as a reflector or a director of the signal which would do more to influence the reception. In addition the radar and those other antennas can create intermod or wave cancelation of the signal. The wave cancelation is a function of the harmonics of the signals of the various devices.

Bottom line as long as the VHF antenna is high and clear you will be fine. If you are trying to DX with the VHF that is another matter.

 

[ImpulseIII]

Yeah, what Paul said !! :thumbsup:

Paul, great explaination...thanks

 

[Presentation]

Where we boat all hailing is done on channel 16. This includes asking for a bridge opening for, …..wait for it…….7 different bridges between three towns, Menasha, Oshkosh and Winneconne.

At times I get tired of listening to all the chatter. I can be 15 miles away and still hear the requests for bridge openings.

In the rules it says you should transmit on the lowest power possible that will do the job. (my words, but that’s what is says) In reality I think many don’t know how to go from 25 watts to 1.

My ‘fix’ has been to lower the antenna. I can still hear a mayday hail that is anywhere near me yet I don’t get all the constant interruptions of having to listen to all the bridge opening requests.

 

[PartnerShip]

When traveling north and south on the ICW I usually keep my antenna at a similar angle. Notice in the photo that it's no higher than the anchor light. Running this way will let you clear a lot of bridges without asking for an opening. My radio communications are usually short range and there is no noticeable change.

 

[Skuza]

I can remember "back in the day" when my dad had his 340 and '85 390 and the cool thing back then was matching your antenna's to the angle of the arch. Then somtime in the '90s it was cool and "sophisticated" to have them straight up and down. Thats the way we're "wearing" our antennas these days! :lol:

 

[Skuza]

I can remember "back in the day" when my dad had his 340 and '85 390 and the cool thing back then was matching your antenna's to the angle of the arch. Then somtime in the '90s it was cool and "sophisticated" to have them straight up and down. Thats the way we're "wearing" our antennas these days! :lol:
Now who remembers when windsocks were cool to have on your antenna??? :smt017