8. One special situation where the line does not alter the impedance is when its length is an
exact multiple of the electrical half wavelength.
9. An antenna tuner will not affect the antenna impedance nor the standing wave condition on
the transmission line. It will correct the SWR on that portion of the line between transmitter
output and tuner input, so that the transmitter will supply rated power to the system.
10. Standing wave ratio, SWR, is a measure of the mis-match of the system and is used as the
indicator when making tuner adjustments. SWR is direct ratio of load resistance to line's
characteristic impedance.
11. SWR other than 1 to 1 indicates two possible impedances, one greater and one less than
characteristic impedance.
12. Any SWR value less than 2 to 1 is considered a good match.
ALIGNMENT
SWR BRIDGE
In the unlikely event SWR bridge adjustment becomes necessary, proceed as follows:
1. Connect a 50 ohm dummy load to any antenna jack.
2. Turn the ANTENNA switch to the same antenna position and S1 to 50 ohm BYPASS.
3. Set the meter switches to 200 W, SWR and REV.
4. Turn the SWR SET to full CW.
5. Apply power from the transmitter on 14 MHz and adjust the trimmer, C27 in the SWR bridge
for a null.
WATT METER CALIBRATION
1. Place S1 in the 50 ohm BYPASS position and connect a dummy load to the output.
2. Connect the transmitter through a calibrated wattmeter to the input.
3. Set the meter switches to FWD, 200 W, and POWER.
4. Apply 50 to 100 watts from the transmitter and adjust R28 (right hand pot) to agree with the
external wattmeter.
5. Set the meter switch to the 2 kW range.
6. Apply 500 to 1000 watts from the transmitter and adjust R30 (left hand pot) to agree with the
external wattmeter.
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