MFJ-941EK Tuner Kit
Instruction Manual
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TESTING
Test and Calibration:
These procedures require the following items:
(1) 100-Watt HF transceiver with adjustable RF-power output
(1) Accurate Wattmeter (Bird with 100H slug or calibrated digital meter)
(1) Accurate 50-Ohm dummy load (100-Watt rating or higher)
(1) Porcelain or plastic light socket with pigtail attached
(1) 40-Watt incandescent "appliance" light bulb (do not use CFC bulb!)
(1) Insulated straight-blade tuning tool for setting trimpots and trimcap
(3) PL-259 patch cables, 3-feet or shorter.
(1) Volt-Ohm test meter (VOM)
Pre-Test Inspection:
Perform these checks and correct any discrepancies.
[ ] Check for loose hardware and tighten as needed.
[ ] Inspect
Antenna
and
Transmitter
capacitor plates for rotor-to-stator shorts.
[ ] With straightedge, confirm inductor is at 1/8" or more below top of panels.
[ ] Inspect inductor. No taps, turns, or switch wires should be shorted together.
[ ] Confirm meter needles both rest on zero.
[ ] Confirm all knob pointers are aligned correctly and turn smoothly.
[ ] Check pushbuttons to confirm push-on, push-off action without sticking.
Meter Lamp:
To test the meter lamp, use the 2.1-mm male power cable and a power source
(12-volts DC or a 9-V battery).
[ ] Connect voltage source to the power cable (either polarity okay).
[ ] Plug 2.1mm cable into
Meter Lamp
on back panel and press
Lamp
switch on.
The meter lamp should illuminate
Antenna Selector Check
:
Use the VOM set at Rx1. The first series checks the
Antenna Selector
in
Bypass
mode. Connect one lead to the center-conductor of the
Transmit
connector on
the back panel. Rotate the
Antenna Selector
switch to each position below and
check the corresponding coax connector for continuity: