Home |
Search |
Today's Posts |
#1
|
|||
|
|||
Anyone know where I can find plans for an artificial ground?
napisal w wiadomosci ... I'm probably known as the anti-ground.. lol.. IE: I don't believe in RF grounds in the shack unless the antenna is fed directly from the shack. Which is fairly rare for me, but I have done it on 160m a few times.. My way of thinking is that an RF ground should always be a part of the antenna itself, preferably away from the shack. IE: a dipole is a complete antenna, and requires no ground for proper operation at the antenna, or at the shack. You don't need an RF ground at all. Your dipole is not the dipole but the monopole with the one radial. In the case of a vertical, the RF ground should be under the antenna if a monopole. IE: ground radials under a ground mount, or elevated radials for a ground plane. Your dipole is a horizontal monopole with the one radial. The vertical monopole can have only one radial. More radials is necessary for a strong stations. Do you understand? The only difference between your monopole and your vertical antenna is the direction. Do you agree? S* With either one of these, no RF ground is required for the shack. Ditto for a half wave vertical, which is a complete antenna. The only worry with it, is feed line radiation, which is a bit different issue. It just needs to be decoupled for the best operation. But that is something to be considered with any antenna, including the dipoles. The only ground I use at the shack is the safety ground for line voltage gear.. All lightning grounding must be at the antenna/mast, and at the entrance to the shack. "ground window". I quit using a shack RF ground in the mid 90's or so.. Ain't missed it all at so far... I actually had more issues when running high power "KW+" with a shack RF ground vs not using one. The use of the ground wire tuning may well help it work better on certain bands to prevent a hot shack. But I consider it a band aid to help hide problems that actually should be addressed at the antenna. Or in a perfect world at least.. BTW, I do not agree with the notion that an antenna needs to be resonant. That is another wives tail, as pointed out by Cecil. Even a dipole that is .05 WL long will radiate nearly all power that is applied to it. And antennas are reciprocal between radiating, and receiving. The trick is getting the power to and from the small antenna without it turning into heat. :/ There can be problems with excess loss, but it's not the element's fault for being non resonant. |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Anyone know where I can find plans for an artificial ground? | Antenna | |||
FA: MFJ-931 1.8-30 MHz HF Artificial Ground | Swap | |||
FS: New MFJ - 931 Artificial Ground | Swap | |||
FS: MFJ artificial ground | Swap | |||
artificial ground | Antenna |