Test tone:
Select the desired test tone, press the “Execute” button to transmit a test signal on the channel selected
for 20 seconds or until the “Cancel current test” button is pressed.
The functions of all the other buttons are inoperative during test transmissions.
Te
s
t Tone
s
Modulated
Test transmission generates a carrier modulated with a test tone to check deviations. For
specific test tone and/or deviation values.
Unmodulated
Test tone is an unmodulated carrier that gives a clear carrier and used for checking:
♦
Frequency error
♦
Forward and reverse power
Power check:
Connect an in-line power meter between the radio and the antenna.
Measure the forward (nominal 27W) and reflected power levels by pressing the Execute
button. Never exceed 1W of reflected power.
100 Hz square
wave
Starts a test transmission of a carrier modulated by a square wave. Used to check low-
frequency balance at a frequency of 100 Hz
Random Data
Starts a 20-second test transmission with a carrier modulated with random data.
Random data test transmission is not usually required.
If low system performance is noticed, System Engineering may request the user to run this
Random Data test for checking low-frequency balance and maximum deviation over data.
Random data test requires the use of an IFR COM-120B service monitor with option 03=
30kHz IF filter and its DC coupled demodulator output selected.
74
