ZETRON 37-MAX, Installation Manual

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Section 5. Installation
5-5
ALTERNATE TEST AND ADJUSTMENT PROCEDURE
There is another way to set up the Model 37-MAX on a new radio system that does not
require having a radio with a DTMF encoder. Cycling the Model 37-MAX through the
various test modes is accomplished using the Disable button on the front of the unit.
1. Complete the installation of the Model 37-MAX to the radio(s). Configure the
Communications Service Monitor to display the deviation of the signal it receives on the
repeater's transmit frequency.
2. Cycle power on the Model 37-MAX while holding the Disable button down. Continue
holding the button for at least two seconds until the Status LED turns on. Release the
button after the Status LED turns on to begin the Alternate Test Procedure.
3. The following test sequence will advance each time the Disable button is pressed. To exit
this mode at the end of the procedure, turn off power to the tone panel. If power is not
cycled, the 37-MAX will return to the normal operating mode on its own, 30 minutes
after the test mode was entered.
Key the transmitter and output a 1 kHz tone.
Output a 136.5 Hz CTCSS tone, no audible tone.
Output a 67.0 Hz CTCSS tone, no audible tone.
Output a 250.3 Hz CTCSS tone, no audible tone.
Output DCS code "023", no audible tone.
Enable Repeat Audio Mode, no tones from the 37-MAX.
4. Transmit Audio Level : Set the deviation level of the 1 kHz tone being transmitted by the
tone panel to 60% of full channel deviation (example: ± 3 kHz deviation on a channel
licensed for 5 kHz maximum). The gross level of this signal can be set using JP4 (
TX
),
and the final level adjustment is done using R3 (
TX LVL
).
5. Encode Output Level : Press the Disable button once to start the 136.5 Hz encode. Set the
encode deviation level for 15% of full channel deviation (example: for 750 Hz of
deviation on a channel licensed for 5 kHz maximum deviation). The gross level can be set
by moving JP2 (
LO/HI
) and the final level is set using R1. Check the position of JP1, it
should be in the 'B' position. The only time JP1 would be moved to the 'A' position is if
the repeater was doing CTCSS encode only on a phase modulated transmitter.
6. Encode Pre-Emphasis Test
:
Press the Disable button once to change the encode frequency
to 67.0 Hz and check that the encode deviation remains close to what it was set at in step
five. Press the Disable button again to change the encode frequency to 250.3 Hz and
check the encode deviation again to confirm that it has remained reasonably constant. 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. If
necessary, move JP1 to the 'A' position and start the encode level setting in step five over