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BASIC BOARD MODULE (BBM)
7-7
4. The tone should pass through the op amp 600 ohm
line drivers, U28A and U28B. Adjust R44 for a
level of -8 dBm ±1 dB at J12.
5. The tone should pass P33, pins 5 and 6 to the
personality card to transformer T201, pins 9 and 10
via the jumper.
• Relay K204 should be active ( < 1V on pin 8)
• Latch U208, pin 16 should be high ( > 4.5V)
• Relay K203 should be active ( < 1V on pin 2)
• Latch U208, pin 17 should be high ( > 4.5V)
• Relay K202 should be active ( < 1V on pin 2)
• Latch U208, pin 18 should be high ( > 4.5V)
• Relay K201, K205 and K206 should be inactive
( > 11V on pin 2 and 8 of each)
• Latch U208, pins 14/15/19 should be low (< 1V).
6. The audio should pass through to the line with a
level of -12 dBm ±2 dB across a series 600 ohm and
2.2 microfarad capacitor.
7.5.2 TEST "2"
This sends 2175 Hz tone from the Tone Remote
Personality Card (-420) to the line.
1. The 2175 Hz tone is generated on the -420 board by
U209, U212 and U213. The tone is passed through
buffer op amp U204B and the major level control
U214A and U214B.
2. The 2175 Hz tone passes through adjustment op
amp U204A.
• Adjust R267 for a level of +8 dBm ±0.5 dB at
EP226.
• This passes through summing op amp U201C and to
the main board via STXA P202, pin 2.
3. The 2175 Hz tone pass through transmission gate
U31A.
• This gate should have a high on the control pin
(U31A, pin 13), from U46, pin 13.
• The transmission gates U30A, U30B, U31D, U31C,
U57A and U31B should be off (< 1V on the control
lines).
• U46, pins 1, 3, 5, 9, 11 and 13 should be low ( < 1V).
U6, pin 15 should be high ( > 4.5V).
4. The tone should pass through the op amp 600 ohm
line drivers, U28A and U28B.
• Adjust R44 for a level of -1 dBm ±1 dB at J12.
• The level should be -1 dBm ±1 dB across the Tx
line.
7.5.3 TEST "3"
This sends a DTMF digit "5" tone from the Tone
Remote Personality Card (-420) to the line.
1. The DTMF digit is generated on the -420 board by
U218.
• The digit passes through adjustment op amp
U201A.
• Adjust R216 for a level of -3 dBm ±0.5 dB at EP223.
• This passes through summing op amp U201C and to
the main board via STXA P202,
pin 2.
2. The digit passes through transmission gate U31A.
• This gate control pin (U31A, pin 13) should be high,
from U46, pin 13.
• The tone should pass through the op amp 600 ohm
lines drivers, U28A and U28B.
• Adjust R44 for a level of -12 dBm ±1 dB at J12.
• The level should be -12 dBm, ±1 dB across the Tx
line.
7.5.4 TEST "4"
This tests the card for sending and receiving data
messages via FSK on the Main Audio and via digital
on the Secondary Data lines. The M-lead and E-lead
circuitry is tested.
1. Sends an FSK message out the main transmit.
• The FSK is generated by U16, then passes through
level op amp U32B.
• Adjust R86 for a level of -12 dBm ±0.5 dB at TP4.
• The FSK then passes through transmission gate
U31C and balanced line driver op amps U28A and
U28B.
• Adjust R44 for a level of -21 dBm ±1 dB at J12.
• The level should be -21 dBm ±1 dB across the Tx
line.