Tait TP9100 Service Manual

Also see for TP9100: User guide Product safety and compliance information User guide Service manual Manual

234 Transmitter Fault Finding TP9100 Service Manual© Tait Electronics Limited May 2005Task 11 óShaper andLevel ShifterIf the voltage measured in Task 10 is correct but not the current, either thePA or the shaper and level shifter for the PA is suspect.Important Ensure that the current limit on the DC supply is 2A. And,when entering the CCTM command 331 x, do not specifya value x higher than that recorded in Task 9. Failure to doso might result in the destruction of the PAs.1. Enter the CCTM command 33 to place the radio in transmit mode.2. Enter the CCTM command 331 x (where x was recorded in Task 9).3. Check that the voltage at the gate of Q106 (see Figure 10.8) is:4. Enter the CCTM command 32 to place the radio in receive mode.5. If the voltage measured above is correct, Q106 is faulty; replace themain board and go to “Final Tasks” on page 134. If it is not correct,go to Step 6.6. Check the circuitry between pin 14 of IC101 (see Figure 10.7) andthe gate of Q106 (see Figure 10.8). If a fault is found, repair it,confirm the removal of the fault, and go to “Final Tasks” onpage 134. If the repair failed or Q106 itself is faulty, replace the mainboard and go to “Final Tasks” on page 134.gate of Q106: 2 to 5V