MFJ-936C
Deluxe High-Efficiency Magnetic Loop Tuner
Instruction & Technical Manual
7.
COAX OUTPUT:
This is one of two
output
ports for using a coax loop instead of wire.
8.
PVC MOUNT:
This is the mount point for the PCV cross assembly.
The MFJ-936C
Deluxe High-Efficiency Magnetic Loop Tuner
™
Rear Panel connections function to
permit connecting the wire loop at the output, and connecting the coaxial line at the input of the
tuner. Refer to Figure 5 and the labeled component locations.
Figure 5: Rear-panel Connections: 1.) Wire loop connectors, 2.) Coax input
1.
LOOP CONNECTORS:
Connect wire loops here.
2.
COAX INPUT:
Connection to transceiver.
A wire loop antenna connects to the Loop Connectors with the two wing nuts provided on the
Loop Connector standoff rods. RF from the transceiver is input at the rear coax port. Care must
be taken not to disturb the wires leading from the lugs on the Loop Connector stand-off rods and
entering through the back of the tuner. The connection points must be kept clean at all times.
This unit is
not
intended for outdoor installation except during portable operation and must be
protected from the elements.
3
LOOP THEORY
A magnetic loop antenna is one that is characterized by low-noise reception, working well even
when mounted at ground level, and a circumference of less than
1
/
3
wavelength. The ideal small
transmitting antenna would have performance equal to a large antenna, and the MFJ-936C
approaches that performance. Bandwidth is quite narrow due to the extreme high-Q of the
tuned-circuit configuration when paired with a capacitor.
The components in a resonant transmitting loop are subjected to high currents and voltages
because of the large circulating currents in the high-Q tuned circuit formed by the antenna. It is
very important that the capacitors used in this antenna have a high RF current rating. Even a
100W transmitter develops currents in the tens of amperes, and voltages across the tuning
capacitor can be greater than 10kV. This consideration also applies to any conductors used to
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Summary of Contents for MFJ-936C
Page 18: ...USER NOTES ...
