BASIC BOARD MODULE (BBM)

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.

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