Anyone using Tram antenna?

[Marz-Bar]

I was wondering if anyone has any experience with Tram antennas? I see them often on ebay for as much as half the price of other companies products. I will be installing a 4' or 5' antenna on the side of my center console. If anyone has any thoughts on antennas or mounts they liked or disliked i would appreciate it . Thanks

 

[Boatist]

Re: Anyone using Tram antenna?

Get the best antenna you can afford. Small diameter felexable antenna do not last very long if you boat in any kind of rough water. Many use tuned coax as a radiator.

A 5 foot antenna mounted 3 feet above the water has a range of 4.02 miles plus the range of the other station.

I like Shakespears 5225 Galaxy. All the 8 foot Galaxy are good antenna but not cheap antennas.

 

[Marz-Bar]

Re: Anyone using Tram antenna?

Hey Boatist I have a question for you. You stated:

A 5 foot antenna mounted 3 feet above the water has a range of 4.02 miles plus the range of the other station.

Is this calc. assuming 0db gain, 3db gain, or 6db gain on my antenna or does it matter?
I am looking at a 4' antenna with 3db gain. Top of antenna would be 8' 6" from water line. A 4 mile range where i boat and fish would be ok for me.

 

[Boatist]

Re: Anyone using Tram antenna?

The DB gain can help you get thru but does not increase the range.
The range is determined by line of site for VHF or curveature of the earth.
Many places DB gain can make a big difference is weather your get thru.

An example would be San Francisco Coast Guard Group.
They have 6 to 9 antenna around the area and some are 3000 feet high so have a long range.

I have talked to them from Sacramento 80 miles east inland and from the Pacific Ocean 80 North.
There coverage is also about 80 mile west and south.
So they cover a big area but it is still line of site.

However on a nice weather weakend there may be 500 boats out to sea in range and another 500 in San Francisco Bay and the Delta.
So it a good bet that channel 16 has a lot of traffic. You can here boats within about 10 miles of you.
Channel 16 may sound clear to you but there could be 20 people talking on 16 that San Francisco Group can here that you can't here.
Many may be closer to San Francisco group than you.
This is where the DB gain comes in. With a 6 DB antenna you have a Efective Radiated Power of 100 watts and could be the station the Coast Guard here even if a boat closer is also talking. This is also why you should use 1 WATT anytime you can. Range is close to the same but the guy making a MAYDAY Call on 25 watts for sinking will be happy he could over power you and get to the Coast Guard.

With a 3DB antenna your Efective Radiated Power is 50 watts.

8.5 foot above the water range is 4.13 Miles plus the range of another Station.
So talking to another average boat with a 8 foot antenna 2 feet above the water your boat to boat range would be 4.13 plus 4.49 or 8.62 Miles.

If you want the formula it is:
The square root of the antenna height above water in feet TIMES 1.42 = distant in miles.

This Is only for VHF Line of Site transmission. HF frequency will bend and can talk further in most cases.

Hope it all makes since.

 

[nuttyboater]

Re: Anyone using Tram antenna?

Tram isn't too bad, they also make commercial radio products, not just marine. Their VHF product line, 150-174Mhz, aren't too bad but they did have some issues with quality control at one time, but who hasn't? Their UHF products, 450-470Mhz are well built.

Anyway, as for their marine stuff, seems well built enough to me. I could buy two of them for the cost of some brand names. It's all a matter of how important it is to you.

I plan on putting a marine VHF one of these days, but for now i have full cell coverage on the lakes i visit, and without anyone on shore or nearby with a radio it doesn't do much good to be shouting on that if i need help.

Around here Marine VHF is where people that don't want to get a commercial radio license hang out, its VHF CB... I don't want to trust my life to that anyway!

 

[Boatist]

Re: Anyone using Tram antenna?

Many inland area are like you talk about. But when you get out in open water VHF is by far safer way to go than cell phone.

Oceans, main shipping lanes and great lakes make sure you have VHF Marine Radio. You will get help much faster than with a cell phone.

People Useing VHF Marine band if anywher near a Coast Guard Station will get caught and pay the penelty. Are you sure they are not useing the GMRS Band?

 

[nuttyboater]

Re: Anyone using Tram antenna?

GMRS is UHF, 462/467, they are using VHF Marine around these parts thanks to the cheap marine radios these days, you can go to one local marine store and buy the radio and a mobile mag mount antenna for less than $100, funny that you shouldn't use it on land yet these dealers sell mag mount antennas for them huh? MURS is another active area, lots of teenagers on there with the 2w radios that RadioShack was selling for a while.

I listen to them all the time chatting on channel 16 on marine VHF. GMRS and FRS is pretty quiet around here, you could be on there for a week without hearing anyone. Why? Because a bunch of kids got busted using them to facilitate criminal activities last year and they know the police here keep an eye on the radio activity there now.

Normally i would agree on the cell phone issue, however, around here most of the lakes i use, and the campgrounds near them, have stellar cell coverage because of the towers being located on the highest hill next to them! There is a few places though that make me wish for a mobile VHF on the boat, but i also keep my dualband 2m/70cm ham HT with me as well. It would probably make more sense around here to have ham radio onboard, but then they don't make many options that are waterproof other than HT's. There is a new radio from Yaesu, FTM-10R, that has a waterproof remoteable control head and mic, but the body of the radio would have to be hidden or enclosed somewhere to protect it.

PS: I'm an Extra Class ham radio operator of nearly 15 years, so i know a thing or two about radios.. lol

 

[Boatist]

Re: Anyone using Tram antenna?

So you got your Extra Class licence while had to do 20 word per minute code?
Thats Great I stopped at Advanced many years ago because I knew it would be very hard for me to do 20 word per minute code. Took a 3 try at 13 wouds per minute. I may some day go get the Extra now that there is no 20 word per minute code however I never use anything but the VHF a UHF Frequencies.

If I had information about people using VHF marine illegaly I would report to the FCC, Coast Guard and local police as it could some day cost some boater his life plus I respect all radio Frequencies.