ZETRON 748, Technical Manual

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Installation
025-9368H 15
ask you to select which method should be used to establish a telephone connection, press any
key to toggle through the choices, press
ENTER
to select.
Using a DTMF telephone:
Enter the correct function code 114# followed by the hybrid tones. Careful for your ears!
Using a DTMF equipped radio:
Keyup and enter DTMF programming mode (12748 default). Enter the correct function code
114# [2 beeps], then select which method should be used to establish a telephone connection,
1# to dial out on the phone line, or 3# to wait for an incoming ring.
Adjusting hybrid:
Monitor the transmit channel with a service monitor or alternately probe C104 (Main PCB)
with an oscilloscope. Adjust R16 and R17 (on Phone Card) for minimum signal. This may
take several times back and forth to work the signal down.
Using a computer or terminal:
Press ENTER to leave the Hybrid balance adjust test. The Model 748 will then terminate the
phone connection.
Using a DTMF telephone or radio:
Press “#” to leave Hybrid balance adjust test. The Model 748 will then terminate the phone
connection.
9. DIAL CLICK ADJUSTMENTS: If you do not have the Dial Click option (950-9589) installed in
your Model 748 you can skip performing this adjustment.
To perform this test requires establishing a telephone connection through the local Central
Office. The Model 748 provides two ways of accomplishing this, answering an incoming call
and starting the test or taking in a phone number, dialing it and starting the test. It will require an
assistant at the distant connection with a rotary phone to perform this test.
Using a computer or terminal:
Select the “Dial click decode” by typing “12” followed by
ENTER
. The Model 748 will ask
you to select which method should be used to establish a telephone connection, press any key
to toggle through the choices, press
ENTER to select. Your assistant should start dialing a
pre-determined sequence or pattern of digits with a rotary phone. You should see the digits as
they are decoded on the CRT. Adjust R6 on the Dial Click card (702-9424) to increase or
decrease the sensitivity of the decoder card. Once you are satisfied with the decoding, press
ENTER to exit the test. The Model 748 will then terminate the phone connection.