 | SB-060 |
| Service Bulletin | Amateur Radio Division |
| Subject: TS-120S - Repair Notes | Date: December 18, 1979 |
| SB-060 |
| Service Bulletin | Amateur Radio Division |
| Subject: TS-120S - Repair Notes | Date: December 18, 1979 |
| Symptom | Repair |
|---|---|
| General Problems | |
| Analog Dial Calibration Off | Mechanical adjustment |
| Loss of Digital Display | Check P5/J5 on Carrier Unit |
| Power on Meter Max | RF gain turned max CCW |
| VFO Drift | See SB-827 |
| PLL Digital NG | Pll unit D15 |
| 15 Meters NG | Broken wafer on BCD band switch or connectors on PLL and RF units |
| No RX or TX 10M only | Q16, 74LS163 on PLL unit bad |
| No CW Filter | Short across pins 1 and 2 J29 IF unit |
| Analog Dial Off | Perform VFO tracking adjustments at 50 and 450 |
| No 15M | Core broken on VCO transformer for 15M |
| 3.5 and 7 Band Same | Short at bandswitch under IF unit |
| Transmit Problems | |
| Carrier in SSB | RF unit D2 and/or D3 shorted (see SB-832) |
| Smoke at Final | Check for burned L10 and L11, L40-1011-04 (100uH) also check for long ends of wire shorted to case |
| TX Audio Bad | Check the carrier point adjust and make sure that the final bias is set to 150mA |
| High IC in RX | Bad finals |
| 28.5 HF Oscillation | Tighten ground screws at Relay unit X41-1250 (see SB-844) |
| Low TX out 40M | 50W on 40M and 10W on 10M bad finals |
| Low RF out all bands | Q12 SN16913 on AF GEN unit, or 2SK19GR bad |
| No TX all bands | L25 on RF unit is open (small green inductor) |
| No Digital No TX | Q12 mixer on the PLL unit bad |
| Intermittent SSB Audio | Pin 5 of J5 on AF unit loose |
| No Key or TX | D26 and Q24 2SA562 on AF GEN unit bad |
| No TX | R8 220 ohm resister at key jack burned open (use shielded line for CW key) |
| 15M Oscillation | Install ferrite bead on base of first Mic amp Q18 on AF GEN unit (see SB-844) |
| No TX | Loss of AVB voltage at RF unit, Q9 2SA473 on FILTER unit or 6 volt Zener diode |
| Receive Problems | |
| No CW, No Audio | Sidetone oscillator Q25 on AF GEN unit 2SC1815 |
| Receiver Sensitivity Down | T1, L34-0696-35 on RF unit shorted (see SB-831) |
| SSB Receive Audio Bad | IF shift control turned max CW |
| No RX | Pins of CW filter not cut off after installation shorting IF to ground |
| No Digital No RX | Q26 mixer on the PLL unit bad |