Home |
Search |
Today's Posts |
#5
![]() |
|||
|
|||
![]()
In article ,
Bill Horne wrote: According to Wikipedia (http://en.wikipedia.org/wiki/Near_Ve...dence_Skywave), a horizontally-polarized NVIS antenna will benefit from a ground wire underneath it. Here's an excerpt: "An NVIS antenna configuration is a horizontally polarized (parallel with the surface of the earth) radiating element that is from 1/20th wavelength ... to 1/8th wavelength above the ground. That proximity to the ground forces the majority of the radiation to go straight up. Overall efficiency of the antenna can be increased by placing a ground wire slightly longer than the antenna parallel to and directly underneath the antenna. While the ground wire is not necessary under good to excellent propagation conditions, antenna gain in the 3 dB to 6 dB range are common when the ground wire is used." Since I've never heard of anyone doing this, or seen any hams trying it, I'd like to hear from those who've done it, and find out if the gain is as predicted. 73, Bill W1AC, who is rushing to get a good sky-hook up before the winter We used a configuration of that principal, for years, when doing communications for the Ididarod DogSled Races out in the bush of Alaska. Put up a Dipole for 80 Meters, strung between the trees, and then ran a Grounded Wire, directly under the Dipole, that was 3% longer, electrically. Increased our ERP for Short Range Comms. Typical Ranges were from 120-500 Miles. KL7BB can give you any details, you could require, if you can track Crazy Bill down...... |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
Ground Wires : Think Free and Effective ! - [Was : Minimum Gauge forGround...] | Shortwave | |||
Safety ground versus RF ground for a 2nd Floor shack | Antenna | |||
What's underneath BBC 5975kHz @ 0257UTC? | Shortwave | |||
Dipoles and the rig's RF ground... | Antenna | |||
Transforming your simple Ground Rod into a Ground Anchor : Is It Worth The Work ? - You Decide ! | Shortwave |