ah.4.12. SB-102-15: Poor AGC Action
June 5, 1978
SB-102 Bulletin No:SSB Transceiver SB-102-15
Leakage in the 6HS6 tubes [PN 411-247] at V10 and/or V11 has been found to cause:
Poor AGC action
Fast S-meter decay
Poor sensitivity when RF gain control is fully clockwise.
This usually occurs after warm up of at least an hour. A positive voltage, usually over 1
volt, will appear at the grid, pin 1, of either one or both tubes.
Replacement of the tube with the positive voltage corrects the problem.
ah.4.13. SB-102-16: 100KHZ Calibrator Spurs
June 5, 1978
SB-102 Bulletin No: SSB Transceiver SB-102-16
Strong signals may occur at other than 100khz points.
Look at the calibrator output [ahead of output diode] with an oscilloscope. Use high
input gain and a slow sweep speed. If the upper portion of the sine-wave signal
appears choppy or uneven, the Y201 crystal may be at fault.
After installation of a new crystal [PN 404-43], recheck with oscilloscope.
ah.4.14. SB-102-17: Poor Preselector Tracking
July 24, 1978
SB-102 Bulletin No: SSB Transceiver SB-102-17
This problem is more noticeable on the 10-meter band. It may be caused by the drive
belt slipping or by one of the variable capacitors not turning due to excessive friction in
its bearings.
Check the belt for being loose or worn and replace as needed. Lubricate the bearing of
the variable capacitors. If lubricating the capacitor bearings does not allow the rotor to
turn freely, replace the capacitor [PN 26-122].
ah.4.15. SB-102-18: Carrier Nulls with C14 Trimmer Plates Completely Meshed
July 24, 1978
SB-102 Bulletin No: SSB Transceiver SB-102-18
If C14 nulls the carrier with its plates fully meshed toward V2 [to the right], relocate C18,
12pf capacitor, to the other section of the null trimmer [C14].
SB-102 Service Bulletins Page 181
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