Radio Antenna Height

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Wallkerbay

New member
I currently have a 4ft antenna. I was having problems hearing :? , so I installed a remote speaker. I can hear much better now. My marina manager is 100 ton captain. I had bought an 8ft antenna. I was going to take it back ,He said to keep it and install it .I had alot of static on my speaker. Squelch did not help much. Any help would be nice. :| My Antenna is currently attached to the hand rail on the cabin roof.
 
Wallkerbay":1swrhmxp said:
I currently have a 4ft antenna. I was having problems hearing :? , so I installed a remote speaker. I can hear much better now. My marina manager is 100 ton captain. I had bought an 8ft antenna. I was going to take it back ,He said to keep it and install it .I had alot of static on my speaker. Squelch did not help much. Any help would be nice. :| My Antenna is currently attached to the hand rail on the cabin roof.
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So if I'm reading you right,

1. your hearing is considerably improved with the extra speaker placement, but

2. you still have a lot of static and difficulty receiving the signal, and

3. you still have the 4 ft antenna, but

4. the dock master wants you to install the 8 footer, right?

Why not try the 8 footer without permanently mounting it by simply substituting it for the 4 footer by unplugging one and plugging in the other? (Be sure the comparison is made at equal heights.)

Should be easy to see if there would be any improvement in performance with the longer antenna. It should offer a higher gain, 6db vs 3db, and be a better performer in both transmitting and receiving signals. Keep it mounted up reasonably high on the boat, as VHF radio communication is basically a line of sight like phenomena.

If you still have a lot of static or interference, it could be that some other electrical or electronic component on the boat is interfering with your reception.

Good Luck!

Joe. :teeth :thup
 
I don't disagree with Joe, and certainly encourage you to substitute antennas for more signals but I do think the "static" you are hearing may be generated on board your boat or by the engine or even a nearby engine. If squelch cannot be set then it's highly likely you have a local problem. The longer antenna won't change your problem and may exacerbate it.

Couple of quick checks. Turn everything off but the radio. Can you set squelch? If not, wiggle the antenna connector. Any change in static? If not, then disconnect the antenna. If you still have static and can't set the squelch with the antenna disconnected then it's probably time to buy a new radio.

Squelch is used to silence the radio when no signals are present. It can and will keep you from hearing weak signals, so setting it is as much an art as it is a science. The larger antenna will bring in more signals and many of the ones that would barely break squelch will easily do it with the bigger antenna, but it's not a miracle worker.

Don
 
Agree with both above answers. Look also at possible corrosion--both on posative and negitive power supply, as well as antenna (how is the PL 259 --antenna plug installed?--best soldered).

Depth sounders are often the culprit for static--route the depth sounder lead away from both the power supply and antenna of the radio.

Also "ferrite beads" are placed on all of the leads to each of the electronics. I had a problem on the Tom Cat, until I went through and changed the leads, put on ferrite beads--all high end equiptment and new--but some of the new electronics put out more interference than you might want.

In the long run, it may be the radio--as suggested. One way to trace this down is to use your hand held VHF radio as a diagnostic tool. Move it around the boat and see where the interference is the most--if no interference, then it is definately in the wiring.

Don't have a hand held--you probably should for safety reasons. Take it in the dinghy, if you ever have "abandon ship", a good water proof VHF may save your life. Plus it is a back up -- both for channel monitering and for failure to the fixed mount VHF.

Also check with the neighbors and see if they have interference.

The higher antenna, may actually accentuate the static if it is a bad radio--as Joe said.
 
The boat was up on a work rack and that was about 20 ft above the water. I had turned the sqelch until I could get a clear recieve signal. I had also removed the AM/FM CD and VHF splitter. I am not a fan of splitters. The signal was loud and clear. I will put the 8 ft antenna in obout the same spot. I will use a rgular mount instead of one on the hand rail. The only thing on was the radio. The radio is mounted on the shelf. The depth sounder is in front of the helm. It could be the spitter that was the problem. :)
 
My guess is you don't actually have "static". Boat radios are FM (frequency modulated) and should be fairly immune to AM ( amplitude modulation) noise which static is defined as.

If you completely disconnect the antenna at the radio do you still have the "static"?

It's true a badly designed radio may not have the best FM detector and it will react to changes in amplitude of an incoming signal. The rise over run or slope of the amplitude changes can be seen by the FM detector as a variation in frequency or phase. Does another radio act the same way?

But I bet if you turn off all other electronics (and your motors) on the boat the noise will stop. I'd further bet that the noise isn't coming in on the antenna but on the power supply lines. While it's true that more signal coming in on the bigger antenna will improve your signal to noise ratio you really want to track down the noise "generator".

As others are saying, try and assure you have good "grounding", ie a low impedance return from the radio to the electrical system. A good connection is more than just a DC connection. It must be a good RF connection.

Everyone's advice that it's one of your other pieces of gear making the noise is good advice. You may not have to go to the effort of ferrite "chokes" if you can separate the radio's power lines and antenna feed line enough to stop the coupling of high rise time crud from the other gear. Every microprocessor on your boat is a fast rise time, harmonic generator that will easily put out RF in the 150mhz range. It's this junk you have to suppress as well as insuring a good antenna and feedline.

Ed.
 
I just found out that I have a major static problem when running the wipers. Did not know it was a problem until I was receiving a signal and using the wipers at the same time. This video actually has a sample of the static I have http://www.youtube.com/watch?v=C0OumEAe4xI it happens about 30 seconds in. Not sure yet if it is coming through the RF or the DC power. Perhaps the static you have is actually interference like mine and the other posts describe. My radio is a West Marine VHF650 and antenna is a Shakespeare Mariner 8700 8-footer and a Shakespeare 4357-S Antenna Splitter for AM/FM separation.
 
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