ZETRON 37-MAX Installation Manual page 39

Section 5. Installation
position, move it to 'B' and try again. Once the level has been set, supply a signal on the
receive channel with test tones of 500 Hz, 1000 Hz, and 1500 Hz while monitoring the
transmit frequency. The deviation should remain reasonably flat for all three tones. If not,
move jumper JP6 to the other position and readjust the receive level (R2) if necessary.
Enter a DTMF "#" to exit this test.
If using a DTMF digit as the test tone, do not hold the digit continuously for more than eight
seconds, or a RESET will occur. If the signal is not being repeated, check that the receiver is
supplying audio to the Model 37-MAX. Some duplex capable radios disable their receivers
while transmitting. If this is the case, the radio will need to be modified before continuing.
6. Encode Output Level: To set the encode level, enter the DTMF command "395#". The
Model 37-MAX will key the transmitter and encode a 136.5 Hz CTCSS tone. Adjust the
potentiometer R1 to set the encode level at 15% of full channel deviation (example: that
is ± 750 Hz deviation on a channel licensed for 5 kHz maximum). If it is difficult to
achieve this deviation, move the jumper JP2 (
again. Enter a DTMF "#" to exit this test.
7. CTCSS Pre-Emphasis Test: Enter the DTMF command "396#" to start the CTCSS pre-
emphasis test. After that, each time a DTMF digit is received, the panel will change to
encoding a new CTCSS tone. The three tones that it will cycle through are 67.0 Hz, 136.5
Hz, and 250.3 Hz, then it loops back again. The deviation levels of all three tones should
be close to the same. If they are not, switch the position of jumper JP1, repeat step six,
and then repeat this test. It is important to the proper operation of the repeater that there
not be more than a few hundred Hertz difference in the encode deviation between the
highest and lowest tones. Enter a DTMF "#" to exit from this test.
8. DCS Encode Polarity: Enter the DTMF command "397#" to start the DCS encode of
"023". Verify that the code "023" is being transmitted. If code "047" is being decoded
instead, then the DCS Encode polarity must be changed using either command "216#" or
"215#". Verify that the encode is being sent at approximately 15% of full channel
deviation. Enter a DTMF "#" to exit from this test.
9. Exit The Program Mode: Enter the DTMF command "99#" to exit the program mode and
return the Model 37-MAX to normal operation. Replace the top cover and mount the
Model 37-MAX in the repeater.
5-4
NOTE:
) to the opposite position and try
LO/HI