Antena bazowa pionowa MFJ-1904 HG18
Truly portable vertical antennas have two basic problems:
- How do you get an effective ground so your antenna will radiate well?
- How do you support and mount a vertical easily and quickly?
MFJ brings you a simple breakthrough solution that is small, easy-to-carry and radiates very well!
The MFJ Ground-Coupled Portable Antenna Base with the Hy-Gain AV-18VS antenna gives you a stable way to mount your vertical antenna and provides an effective ground by just plopping down the base and standing on it to push the legs firmly into the ground. Itll support many multi-band verticals.
You can operate 160 Meters thru 6 Meters and above almost anywhere with an effective signal. Its perfect for traveling or for semi-permanent summer/winter homes. You can easily set it up and take it down your vertical antenna for stealth operation if you live in an antenna-restricted area.
Time Proven Principle
Mobile antennas on cars, truck and other vehicles are grounded by the vehicle body acting as one plate of a capacitor coupling RF to ground. The time proven principle needs no tuning and the antenna radiates well and gives good SWR on all bands. The capacitance to ground is proportional to the area over ground and inversely proportional to the distance between ground and the car body.
In other words, by reducing the distance between the capacitor plate and ground, the area of the capacitor plate (the car body_ can be reduced dramatically. If that distance is reduced to near zero the capacitor plate can be very small.
A 2x2 foot square of metal firmly against the ground can approximate the capacitance of a car to ground. This provides an effective ground for vertical antennas. A mobile antenna using this capacitance ground will perform about the same as on a car. If the antenna is made longer than a normal mobile whip -- which you can do in fixed portable operation -- the antenna performance can be far better.
The MFJ-1904 Ground-Coupled Portable Antenna Base is a 2x2 foot stainless steel square with reinforcing bends that greatly strengthens it. There is a folded and tapered six-inch stainless steel leg on each corner.
Two antenna mounts let you use a variety of vertical antennas. Two handles make carrying and removing the base fast and easy. You can also attach radials for improved performance. Stainless steel construction means youll get trouble-free service for years. The base is anchored into the ground by stepping on each corner and forcing each leg into the ground. The design of each stainless steel leg firmly anchors the base into the ground.
The base can support a lightweight multi-band vertical antenna -- like the all band Hy-Gain 18AVS -- and provide a semi-permanent installation. you can even hide the base by covering it with dirt.
A built-in antenna mount with two U-bolts lets you mount most standard and homebrew vertical antennas. A SO-239 coax connector is attached to the mount for easy connection. Assembly required.
A standard 3/8 inch x 24 mobile antenna mount is also built in so you can use readily available mobile antennas like the MFJ HamTenna Mobile Whips, Hustlers, bug catchers and screwdriver antennas.
Package includues MFJ-1904 Portable Antenna Base and AV-18VS Antenna.
- Antena pionowa KF MFJ-1904 HG18 - instrukcja obsługi (ang.)