MFJ-1623 Instruction Manual
Window/Balcony Mount Antenna
1
MFJ-1623 Window/Balcony Mount Antenna
Introduction
The MFJ-1623 Window/Balcony Mount Antenna was designed to provide portable or permanent HF
communications on 30 through 10 meters and VHF on 6 meters. The universal mount design allows the
user to install the antenna in many ways. The mount will easily attach to window frames, balconies, and
railings. The MFJ-1623 works well indoors mounted to a desk or table as well.
The antenna consists of a whip tuner designed for tuning short whips as well as virtually any random
length wire antenna, collapsible whip, universal mount, and counterpoise wire. The operating frequency
is found by turning the knobs on the whip tuner and setting them for maximum RF current. The
counterpoise wire length can also be adjusted for maximum RF current. The MFJ-1623
Window/Balcony Mount Antenna will allow the operator to get on the air from locations where antenna
size is limited.
The whip tuner section uses a reversible "L" network. The advantage of the “L” network is that it has
only two tuning controls, and only one tuning solution for given impedance match. The MFJ-1623 has
rear panel connectors for coaxial input and a “Hi-Z/Lo-Z” switch for reversing the “L” network. An
internal input-isolating current balun provides isolation of DC and RF grounds for optimum tuning of the
RF counterpoise.
An RF Current Meter indicates the summed antenna and counterpoise antenna currents, making tuning
particularly easy. Simply tune for maximum RF current.
Choosing a Mounting Position
WARNING:
ALWAYS ATTACH THE SAFETY ROPE TO A STABLE SUPPORT
BEFORE ATTEMPTING TO ATTACH THE UNIVERSAL MOUNT TO A
WINDOW FRAME OR RAIL. INJURY AND DAMAGE COULD OCCUR
IF THE ANTENNA WERE TO FALL.
1. Locate the MFJ-1623 in a convenient location. The best performance will be obtained by
placing the antenna outside, however the antenna may be used indoors if necessary. Avoid
placing the tuner near microphones, speech processors, computers, TNC's or other RF
sensitive devices.
2. The design of the antenna allows it to be installed in many ways. It can be easily attached to a
window frame, window box or balcony railing. A Wooden fence is another common mounting
location. The counterpoise is simply placed on the floor. Some installations may require the use
of a C-clamp or vice-grips to secure the base plate.
