MFJ MFJ-935C, Инструкция по эксплуатации, Страница: 10 / 19

MFJ-935C High-Efficiency Magnetic Loop Tuner Instruction & Technical Manual
The MFJ-935C High-Efficiency Magnetic Loop Tuner/Antenna Current Meter
™
uses fixed-length
wires or coaxial cables which will create a Standing Wave Ratio (SWR) around 1.5:1. Exact
frequency coverage depends on each individual installation’s choice of wire or coax length and
diameter, shape of the loop, height above ground level, and operating environment.
The MFJ-935C High-Efficiency Magnetic Loop Tuner/Antenna Current Meter
™
has a mount for
either an MFJ-57B or MFJ-58B PVC Cross assembly or your own homebrewed assembly. The
assembly is inserted into the three-quarter-inch PVC receptacle mounted on the top of the unit’s
cover. Assembly takes less than five minues from opening the packaged kit to operating! Care
should be taken, to secure the loop if wind becomes a factor in the operating environment.
2.2 FEATURES
•
Powerless: No power supply required.
•
Maximum Input Power: 150 Watts (all modes)
•
Easy-to-Read Loop RF Current Indicator: 0-100 unitless scale with adjustable
sensitivity
•
Easy-Carry Handle: Permits easy handling to/from portable location(s)
•
Small Physical Profile: 5.75” wide, 8.75” deep, by 4.25” tall
•
Low Radiation Angle: Rivals full size dipoles.
•
Quiet Reception: Extremely quiet receiving antenna. High-Q design rejects out-of-band
interference and harmonics and reduces overloading.
•
Indoor Use: Perfect for apartments, hotel rooms, antenna restricted and portable locations.
2.3 CONTROLS & CONNECTIONS
The MFJ-935C High-Efficiency Magnetic Loop Tuner/Antenna Current Meter
™
front panel
controls and indicators (Figure 4) function to permit resonating the wire loop at the output, and
matching the coaxial line impedance at the input of the tuner.
1. TUNING: This adjusts the Butterfly capacitor.
2. MATCHING: This matches the tuned loop to a 50Ω coaxial cable.
3. METER SENSITIVITY: This adjusts the sensitivity of the current meter.
4. COAX OUTPUT: This is one of two output ports for using a coax loop instead of wire.
5. ANTENNA CURRENT METER: This displays the current passing through the antenna on
a unitless 0-100 scale.
6. PVC MOUNT: This is the mount point for the PCV cross assembly.
The MFJ-935C High-Efficiency Magnetic Loop Tuner/Antenna Current Meter
™
front panel
controls and indicators function to permit matching the wire or coax loop to the coaxial line at the
input of the tuner. Refer to Figure 4 and the numbered component locations.
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.
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