NOTE: This does not include a light bulb.
Check for normal Het. Osc. test-point voltage.
Check for proper LMO injection voltage 1.0-1.5 VRF.
Check for a high AC ripple content in the LV-B+, HV-B+ and bias voltages from the power
supply.
Check to be sure that the shafts do not touch each other in the insulated coupling, and that the
set screws do not touch the PA shield.
Check to be sure that the PA tune shaft turns the variable capacitor & is not slipping in the
insulated coupling.
ah.4.8. SB-102-8: Alternate Method of Neutralizing the Final Amplifiers
May 23, 1974
SB-102 Bulletin No: SSB Transceiver SB-102-8
NOTE: Be sure unit is off and power supply high voltage capacitors are discharged.
1. Disconnect final plates & screen grid.***
Turn unit on.
Rotate the BAND switch to 28.5.
Place the VTVM RF probe in the ANTENNA connector.**
Set the FUNCTION switch to TUNE.
Rotate the LEVEL control fully clockwise.
Adjust the PRESELECTOR control for a maximum reading on the VTVM.
Adjust the FINAL control for a maximum indication on the VTVM, with the LOAD control set
at the 50 ohm position.
Using an insulated screwdriver, adjust neutralizing capacitor for a MINIMUM indication on the
VTVM.
Readjust the neutralizing capacitor for a minimum indication on the VTVM.
Turn the FUNCTION switch to the off position.
Discharge high voltage power supply capacitors.
Reconnect final plates & screen grid.**VTVM & RF probe will be needed.
***To remove screen voltage in SB-100, SB-101, HW-100 & HW-101 disconnect R920
(100 ohm resistor) from buss wire between pins of V8 & V9. In the SB-102 removal of
accessory plug is all that's required. To remove high voltage in SB-100, SB-101 & SB-
102 disconnect red wire at lug 4 (in SB-100 lug 3) of terminal strip BK that goes to
grommet BL. In HW100 & HW101 disconnect red wire going to lug 1 of RF choke in
final cage.
SB-102 Service Bulletins Page 179
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