                        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]


