Stanford SR445A Quad 350MHz Preamplifier

The Model SR445A 350MHz Preamplifier contains four wide-bandwidth, DC-coupled amplifiers, each with a gain of 5. The four channels may be used independently, or cascaded to provide a total gain of up to 625. The fast rise time, low noise and excellent DC accuracy of the SR445A make it an ideal instrument for amplifying the outputs of fast photomultiplier tubes and photodiodes. The SR445A can be used to improve the sensitivity or oscilloscopes, photon counters, boxcar averages, spectrum analysers and other high-frequency test equipment.

Features:

• 4 independent channels
• DC to 350 MHz bandwidth
• 1 ns rise/fall time
• 6.4nV/ √ Hz input noise
• Voltage gain to 625
• 50 Ω input and output impedance
• 3ns overload recovery

Each channel has an input and output impedance of 50 Ω. The input impedance of channel 1 can be increased to approximately 500 Ω by a front-panel switch. This can improvde the sensitivity of signals from current and charge output devices, such as photomultiplier tubes. Each channel has a separate offset adjustment allowing you to quickly null DC errors.