Home |
Search |
Today's Posts |
#6
posted to rec.boats.electronics
|
|||
|
|||
how does marine vhf antenna work?
In article ,
"Meindert Sprang" wrote: These antennas are half-wave antennas and they don't need a counterpoise. Only a quarter-wave antenna needs one, to account for the other missing quarterwave part, so to speak. Meindert Well, that is not actually true in most cases. If you actually take a Shakespear Fiberglass VHF Antenna apart, you will find that they are 1/4 wave driven elements, with 1/4 wave of Ground Sleeve shoved up the inside of a hollow fiberglass fishing pole and epoxed in place. The really High Gain ones, are Colinear Arrays of 1/4 Wave Segments over a 1/4 wave Ground Sleeve, again shoved up a hollow fishing pole and expoxed in place. Cheap to build and no tuning elements to mess with like your endfeed 1/2 wave whips. Morad 156HD's are actually an Endfeed 5/8 Wave with a matching element built inside the aluminum 1/4 Wave ground sleeve. Mechanically, very rugged, and electrically extreamly rugged. They are the most common VHF Antenna used in the North Pacific, and Bearing Sea. Bruce in alaska -- add a 2 before @ |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
VHF Marine Radio Antenna | Electronics | |||
West Marine is Terrible | Cruising | |||
Which Type of VHF Radio Antenna Is Suitable for a 18-Ft Fiberglass Center Console? | General | |||
Custom Marine Grade LCD Displays = Great Deal | Electronics | |||
FS; Custom Marine Grade LCD Displays | General |