[Tom, Jeff]

The SPI amplifier chassis' (S2500712, S2500713) were modified to increase their transimpedance gain, based upon testing in the optics lab from Jeff. Resistors R4 were changed to modify the gain, and capacitors C5 were changed to maintain circuit stability and bandwidth. Exact component changes summarised below:

S2500711

CH1: R4 = 1.5kohm, C5 = 2.2nF
CH2: R4 = 1.5kohm, C5 = 2.2nF
CH3: R4 = 1.5kohm, C5 = 2.2nF
CH4: R4 = 1.5kohm, C5 = 2.2nF

S2500712
CH1: R4 = 5kohm, C5 = 560pF
CH2: R4 = 5kohm, C5 = 560pF
CH3: R4 = 3.3kohm, C5 = 1nF
CH4: R4 = 3.3kohm, C5 = 1nF

CH5: R4 = 3.3kohm, C5 = 1nF
CH6: R4 = 3.3kohm, C5 = 1nF
CH7: R4 = 3.3kohm, C5 = 1nF
CH8: R4 = 3.3kohm, C5 = 1nF

S2500713
CH1: R4 = 54kohm, C5 = 56pF
CH2: R4 = 54kohm, C5 = 56pF