August 14, 1973 SB-313 Bulletin No: SWL Receiver SB-313-1 Intermittant Connections Of The IF-Audio And BFO-Power Suppy Boards Installing spacers [PN 255-1] between the chassis and connector mounting plates reduces spacing between board connectors & chassis connectors. This assures a much tighter connection and allows a better orientation of switch wafers to shafts, etc. The #6-1/4" smet screws are to be replaced with #6-3/8" smet screws - 12 required. Threaded press-in standoff spacers will appear in production when parts are available. -------------------------------------------------------------------------------------------------------------------- January 11, 1974 SB-313 Bulletin No: SWL Receiver SB-313-2 Instability Oscillations [audio] can be cured by tinning the edges of IF and BFO circuit boards to improve grounding. ------------------------------------------------------------------------------------------------------------------- August 6,1974 SB-313 Bulletin No: SWL Receiver SB-313-3 Lack Of Heterodyne Oscillation On 21.3 Mhz Band Some SB-313 field units have exhibited oscillator starting problems on the 21.3 Mhz band. This can be resolved with the addition of a 10 pF disc ceramic capacitor [PN 21-3] across the 30.195 Mhz crystal Y109. ------------------------------------------------------------------------------------------------------------------ March 25, 1975 SB-313 Bulletin No: SWL Receiver SB-313-4 No Reception The wafer switch [PN 63-615] used on the Antenna Switch board has been shipped with the wrong type lug installed at lug 7 of wafer B; rear. A standard type lug was used in this lug not being connected to foil "E". These switches can be used by connecting a jumper wire between lug 7 of the switch and foil "E". Quality Assurance was notified and all defective PN 63-615 switches were removed from factory stock. -------------------------------------------------------------------------------------------------------------------- June 6, 1975 SB-313 Bulletin No: SWL Receiver SB-313-5 Bulb Obsolescence The frosted lamp [PN 412-20] is no longer available. If replacement is necessary, use a clear #47 lamp [PN 412-1] with a frosted cap [PN 413-39]. -------------------------------------------------------------------------------------------------------------------- October 22, 1975 SB-313 Bulletin No: SWL Receiver SB-313-6 Circuit Breaker Screw Strips Out Before replacing the circuit breaker because the threads have been stripped, try using a slightly larger screw, [PN 253-55] to secure the breaker. ----------------------------------------------------------------------------------------------------------------- March 4, 1976 SB-313 Bulletin No: SWL Receiver SB-313-7 Crystal Oscillator Fails To Start This problem can be corrected by installing the following change: Change: Q102 from [PN 417-133] to [PN 417-172]. The replacement 417-172 transistor is a 3-lead plastic-case device, whereas the 417-133 is a 4-lead Metal case transistor so be sure the transistor leads are installed in the correct holes. -------------------------------------------------------------------------------------------------------------------- January 14, 1977 SB-313 Bulletin No: SWL Receiver SB-313-8 Replacement Parts For SBA-310-2 that are NLA ++++Information not available at this time++++ -------------------------------------------------------------------------------------------------------------------- Thats everything I hold up to 1989 that covers the SB-313. Enjoy! -------------------------------------------------------------------------------------------------------------------- Okay Gang - That takes care of the SB-3XX series up to 1989. As stated before, if I am able to obtain the missing TEB's, I will fill in the missing ones. Ciao! -------------------------------------------------------------------------------------------------------------------- 73 de Joe W7LPF/4 [NNN0KUU] QWCA - SOWP - NCVA - FISTS - RCC Gordonsville, Va 22942 [Orange Co]