MFJ-993B IntelliTuner Automatic Antenna Tuner
Instruction Manual
2005-2012 MFJ Enterprises, Inc.
29
Power-Down Circuit Test
When the 12 VDC power to the tuner is turned off, the tuner saves all settings to non-volatile memory.
The Power-Down Circuit Test checks the power down detection circuitry. It is recommended that this
test be done immediately after the regular self-test described above.
Note:
The tuner must be reset to factory defaults before performing this test.
Here is the test procedure:
1.
Make sure power to the tuner is off.
2.
If the tuner has been reset to factory defaults, skip to step 6; otherwise continue with step 3.
3.
Press and hold
both
the [TUNE] and [L-DN] buttons while turning the power on.
4.
Release both buttons when
DEFAULTS RESET
appears on the display.
5.
Turn the power off.
6.
Press and hold
only
the [L-DN] button while turning the power on.
7.
If the power down detection circuitry is okay, a repetitive message
PASS
will be displayed and sent
as Morse code (di-dah-dah-dit di-dah di-di-dit di-di-dit). If there is a problem, message
PD FAIL
will be displayed and sent as Morse code repetitively.
8.
Turn the power off.
Relay Test
WARNING:
Turn off the transmitter power or disconnect the transmitter before performing
this test; otherwise, damage to the tuner can result.
To test the relays and their control circuitry, press and hold the [C-DN] button while turning the power
on. The message
RELAY TEST
will appear. Four numbers representing the relays will be shown in the
center of the display. The [C-UP], [L-UP], [C-DN] and [L-DN] buttons, corresponding to the position of
the relay numbers on the display, are used to toggle each relay on and off. Press button to engage the
relay and release it to disengage the relay. Listen for relay clicks. Press the [TUNE] button to proceed to
the next group of four relays. There are 19 relays in the tuner. Repeat the above procedure to test all the
relays. Normal operation is resumed after this test.
Firmware Version Number via Meter
Make sure the meter is calibrated. The firmware version number is shown in the copyright message of
the self-test. To obtain a decimal firmware version number via the meter, press and hold the [C-UP]
button while turning the power on. The version number X.YY is represented by the meter forward needle
for X (forward reading
÷
10) and the reflected needle for YY (reflected reading). For example, forward
needle on 10-watt mark and reflected needle on 20-watt mark represent firmware version number 1.20.
Release button to resume normal operation.
