May 15, 1979 SB-201 Bulletin No: Linear Amplifier SB-201-1 Sheet Metal Screws Will Not Tighten If the perforated covers will not secure properly due to enlarged sheet metal holes, install a 6-32 speednut [PN 252-22] over the lip and surrounding hold. The 6-32 X 3/8" sheet metal screw [PN 250-8] will then tighten securely. Using the speednuts does not noticeable degrade the products' shielding capabilities. ------------------------------------------------------------------------------------------------------------------ December 10, 1979 SB-201 Bulletin No: Linear Amplifier SB-201-2 Interfacing the Linear To Kenwood Exciters ++++Information not available at this time++++ ---------------------------------------------------------------------------------------------------------------- January 21, 1980 SB-201 Bulletin No: Linear Amplifier SB-201-3 Apparent Self-Oscillation When Used with Kenwood Transceivers ++++Information not available at this time++++ ---------------------------------------------------------------------------------------------------------------- March 7, 1980 SB-201 Bulletin No: Linear Amplifier SB-201-4 Interfacing the Linear to Kenwood Exciters ++++Information not available at this time++++ ----------------------------------------------------------------------------------------------------------------- July 29, 1980 SB-201 Bulletin No: Linear Amplifier SB-201-5 Chassis Reinforcement ++++Information not available at this time++++ ----------------------------------------------------------------------------------------------------------------- September 2, 1980 SB-201 Bulletin No: LinearAmplifier SB-201-6 RFC3 Overheats And Circuit Breakers Trip ++++Information not available at this time++++ ------------------------------------------------------------------------------------------------------------------ January 30, 1981 SB-201 Bulletin No: Linear Amplifier SB-201-7 Conversion For 10-Meter Operation ++++Information not available at this time++++ ------------------------------------------------------------------------------------------------------------------ January 27, 1982 SB-201 Bulletin No: Linear Amplifier SB-201-8 No output or Plate Current ++++Information not available at this time++++ ----------------------------------------------------------------------------------------------------------------- February 9, 1982 SB-201 Bulletin No: Linear Amplifier SB-201-9 Correction to SB-201-4 ++++Information not available at this time++++ ----------------------------------------------------------------------------------------------------------------- October 29, 1982 SB-201 Bulletin No: Linear Amplifier SB-201-10 Unit Oscillates When Used With An Antenna Tuner ++++Information not available at this time++++ ----------------------------------------------------------------------------------------------------------------- April 6, 1984 SB-201 Bulletin No: Linear Amplifier SB-201-11 Interfacing the Linear to Kenwood Exciters The ALC voltage to Kenwood transceivers and transmitters should not exceed -8 volts. To Ensure the proper voltage to the Kenwood, add: An 8 volt zener diode [PN 56-621] across the ALC connector on the back of the amplifier. Connect the banded end of the diode to the ground lug. Adding a control in the ALC line (as instructed in previous bulletins) to control the level of ALC voltage doesn't always work. This control loads the ALC line so much that very little ALC voltage is developed, resulting in the exiter overdriving the linear, In units which have the control installed and the operation is still unsatisfactory, return the ALC circuit to its original design and install the zener diode. ------------------------------------------------------------------------------------------------------------------- Thats everything I hold up to 1989 that covers the SB-201. Enjoy! ------------------------------------------------------------------------------------------------------------------- [[[Note: I have included the Bulletins that I yet to obtain - hopefully I will be able to get them and 'fill in the blanks' for us all.]]] 73 de Joe W7LPF/4 [NNN0KUU] QWCA - SOWP - NCVA - FISTS - RCC Gordonsville, Va 22942 [Orange Co]