Digital 8' vs Digital 4' VHF antenna performance

[Midnight]

I will be purchasing a pair of VHF Digital antenna's. I understand the db gain issue between the two different lengths, however what does it really mean in performance. In a laymans terms is the extra length worth the investment. I have a perference for the 4'on top of my radar arch cosmetically rather than the 8'. First hand experience appreciated! Thanks

[Sea_Dad]

the 8' is 6db gain, the 4' is 3db gain.

All things being equal the 8' will get nearly twice the distance.

[Chaps]

The Digital 4' is 4.5 db

28' Maxcat w/twin Honda 225's

[Birdman]

quote:Originally posted by Sea_Dad:
the 8' is 6db gain, the 4' is 3db gain.

All things being equal the 8' will get nearly twice the distance.

Not only does the 4' antenna have a db gain of 4.5, it will perfrom almost identical to the 8' on MOST boats. To make a long story short, there is not much difference between the two. Trust me. I'm sure Thom will jump in here and explain why!

Birdman, Capt of

[Sea_Dad]

doh. guess I shoulda checked before blurting.

the relationship is the same. the 8' will get further than the 4' by the ratio of their db's.

[tpp517]

The higher the gain the more compressed the signal is. While it is true a 6Db will out talk a 4.5Db higher gain is not always better. If your antenna is to be mounted on a T-top I would use the 4'. In a heavy sea the motion of the boat makes the higher gain antenna less of a performer, as the tight pattern comming off the antenna is "talking from sea to sky". The 4.5Db gain antenna will be more forgiving in a rough sea, allowing you to make the connection you seek.

[Kid Stuff]

My 4 foot Digitl @ 4.5db outperforms my 8 foot shakspere @ 6db because of the shape of the signal. The 6db will outperform a 4.5 db if seas are dead calm.

[NewMoon]

Who has the best pricing on digital antenna's? Should I go with the 4' or 8' on my center console? It will be mounted on a T-Top. I have a 8' cheapo Shakespeare on there now, that is terrible.

202 Scout Sportfisher, Suzuki 140HP, fish out of Point Judith, RI

[reel hungry]

A company named Gam makes a 3 foot whip thats 6db,my buddy has it and a galaxy 5225 6db on two separate Icoms and other than height they work pretty much the same the taller 8' might get out a little farther.JMO



Tim,25'Skipjack FB Diesel
Reel Hungry

[Mumblerone]

The greater the db the greater the distance, period. Also the greater the heigth, the greater the distance. The 3 db antennas (4.5 db, too) were designed for sail boats that are healed over most of the time. In my opinion, a power boat, on average, (in heavy seas, less so) is nearly straight up most of the time...for a lot of reasons. I know that a lot of people use a shorter antenna very successfully (but not maximizing their VHF) , but some day you'll you'll need that extra range! As an aside check out www.icomamerica.com many units do not put out the advertized wattage after you've held the mic down for a few minutes...check this out too. Icom does! You'll note on attached picture the antenna is 4 degree foreward at rest, straight up when I'm running (small point). Summary: height, high db, and max wattage equals perfect setup.

"Never enough time to do it right; ALWAYS enough time to do it over." Boston Whaler, "MUMBLER", 24' Outrage (1996), twin 175 HP Evinrude Ocean Pros. Snowball, the cat...

[Lead_Head]

Try brokenlegdave.com for Digital antennas.

[son of a butcher]

Just got one from Bethelmarine.com $68.75
4 foot 4.5db