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TRML R
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Line 3:
a. With the handset off-hook, if applicable, press the intercom button (the handset PTT can be used but
audio may be passed over the air) and adjust the Line 3 Tx audio pot (R104) while saying and holding
the word "Five" into the handset until 0dBm is measured across the phone line at the termination panel.
b. Turn "on" dip switch 7 (located on bottom of unit) and key the remote to lock up the 1950Hz function
tone. Adjust R80 tone level (located on baseboard, underneath middle board) until the 1950Hz
function tone measures 0dBm across the phone line at the termination panel.
c. Return dip switch 7 to the "off" position and proceed to the next line output adjustment.
Line 4:
a. With the handset off-hook, if applicable, press the intercom button (the handset PTT can be used but
audio may be passed over the air) and adjust the Line 4 Tx audio pot (R85) while saying and holding
the word "Five" into the handset until 0dBm is measured across the phone line at the termination panel.
b. Turn "on" dip switch 7 (located on bottom of unit) and key the remote to lock up the 1950Hz function
tone. Adjust R80 tone level (located on baseboard, underneath middle board) until the 1950Hz
function tone measures 0dBm across the phone line at the termination panel.
c. Return dip switch 7 to the "off" position and proceed to the next line output adjustment.
Tx Notch Filter
The Tx 2175Hz notch filter is tuned at the factory and should not be readjusted. In the event that the notch filter
needs to be adjusted, the procedure follows:
Note:
Adjustment and measurements are made on the baseboard.
a. Apply 0dBm, 2.2Vpp, 2175Hz signal on the Line 1 red and green phone line input.
b. Using a test clip, jumper left side of R6 to left side of R61.
c. With the scope in the single channel mode, connect probe to U8 pin 7. Adjust R52 to obtain a minimum
signal level. Adjust R54 to further reduce the signal level. Recheck R52 then R54 for the smallest
minimum signal level achievable.
Selected Rx Notch Filter
The selected Rx 2175Hz notch filter is tuned at the factory and should not be readjusted. In the event that the
notch filter needs to be adjusted, the procedure follows:
Note:
Adjustments and measurements are made on the baseboard with Line 1 selected.
a. Apply 0dBm, 2.2Vpp, 2175Hz signal on the Line 1 red and green phone line input.
b. Using a dual channel scope in the X-Y mode, connect one probe to U2 pin 14 and the other probe to U3
pin 8.
c. Adjust R39 until the lissajous pattern closes to a flat line. Remove probes.
d. With the scope in the single channel mode, connect probe to U3 pin 14. Adjust R38 to obtain a minimum
signal level. Readjust R39 slightly to further reduce the signal level. Recheck R38 then R39 for the
smallest minimum signal level achievable.
Unselected Rx Notch Filter
The unselected Rx 2175Hz notch filter is tuned at the factory and should not be readjusted. In the event that the
notch filter needs to be adjusted, the procedure follows:
Note:
Adjustments and measurements are made on the middle board with Line 2 selected.
a. Apply 0dBm, 2.2Vpp, 2175Hz signal on the Line 1 red and green phone line input.
b. Using a dual channel scope in the X-Y mode, connect one probe to U3 pin 1 and other probe to U8 pin 8.
c. Adjust R55 until the lissajous pattern closes to a flat line. Remove probes.
d. With the scope in the single channel mode, connect probe to U8 pin 14. Adjust R73 to obtain a minimum
signal level. Readjust R55 slightly to further reduce the signal level. Recheck R73 then R55 for the
smallest minimum signal level achievable.
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