VHF Antenna

[Legacy]

Hi all. Need to replace my VHF antenna. Defender has one that's 16' and the same model in an 8' version. Since it'll be mounted on my tower, should I still opt for the tallest?

Here's a description:

Digital antennas incorporate several technological breakthroughs which allow them to transmit farther than any other antenna.

An exclusive advanced ground system internal to all digital antennas gives these antennas greater range by directing the rf power closer to the water (see diagram above).

Most antennas lose 50 to 90 percent of the rf power due to a poorly grounded design! In order to eliminate signal loss in the antenna itself, every digital antenna is tuned for a minimum standing wave ration (swr) which approaches 1: 1that translates to low, low signal loss.
In addition, a ferrite choke bead is used to contain rf power in the antenna system, directing it into the radiating element and preventing it from leaking back into the transmission cablethis is a big problem with other antennas.

Finally, a marine grade low loss UV protected rg-8x cable is supplied to reduce transmission line loss. All antennas are made with a tough high-gloss white urethane finish.
Black and black/gold special ordered add 5%.

This model:
Gain- 10. 0 Db,
Size- 16 ft. ,
High performance VHF,
Cable- 20 ft. , Black/gold n.l.a.


Thanks.

Rick

[N4QC]

The Digital Antenna site points out that the 532-VW antenna should have a support mounted 3 to 4 feet above the base. The antenna does come with a Mini-UHF to PL-259 adapter plug.

I would be concerned about possible corrosion build up over time at the joint, as it is a 2 piece antenna. However, if you have access to a RF SWR/Watt meter, or a SWR Analyzer, you can keep track of the quality of your output signal.

Looks like there is but twenty feet of cable…

Would you ever need to lower the antenna…

Height helps the distance aspect, but if the guy on the other end has basically the same configuration as you, except he has an eight foot antenna, if he can hear you on his receiver - you may not be hearing him on his transmit depending on the distance…

10db gain is much better than 6db – more than twice as much…


Hope this helps,

[mhanna]

I like how the article says they say the antenna is made close to a 1:1 SWR. It better be or its not an good antenna ...
More gain is good but everything comes with an expense. You pattern will be tighter and thus when the boat rolls signals may come in and out. If you have this years West catalog, read the article on page 28 about antennas.
As N4QC stated use an SWR meter every year when commissioning the boat, I do and found this year that the reading moved away from 1:1 alot. I tried this and that to fix it but it was probably a bad connection somewhere in it. I waited for a sale and bought a good antenna (one made with brass base, and good inside to prevent corrosion) and its working very close to 1:1 again.

You did not say why you are replacing it, if you think its just not transmitting/recieving it could be the 259 connector ? have you tried cleaning, replacing that ?

Good luck
Matt

[Legacy]

Thank for the thoughts guys. My antenna is quite high as it is mounted on my tower. I can hear everything clear as a bell, but when I transmit, people even close by, can barely hear my. My assumption was that I needed a new antenna. I'll check all connections again. The radio and antenna are almost 10 years old so maybe it's time for an update anyway.

Rick

[Mariner]

It could also be your radio, or even just the microphone. Does your unit have a PA function? That's a good way to test if the mic is working right.