External pre amplifier
Although all Spectrum A/D cards have a very powerful input section with a highly configurable input amplifier and a variety of input ranges it is sometimes necessary to have additional external amplifiers if the signal to acquire has an extremely low level. Spectrum offers a range of perfectly matching external amplifiers to cover such cases. These powerful amplifiers have been rated using the Spectrum cards and offer best performance together with high amplification rates.
The amplifiers are simply connected between the signal source and the Spectrum A/D card input and can be manually switched between different settings using small lever keys. All amplifiers allow the offset compensation by using an adjustable screw.
Very low Input Noise
Low input noise is very important for a good signal-to-noise ratio, especially when amplifying small signals. All SPA Amplifiers are optimized for minimum input noise reaching excellent values as low as 0.9 nV/√Hz.
Currently there are 7 different models available to match different speed grades and signal settings. For optimum signal-to-noise performance choose an amplifier with sufficient bandwidth corresponding to the required signal bandwidth. However, keep in mind that unnecessary high bandwidth introduces more wideband noise.
- SPA.1841: 2 GHz bandiwtdh, 40 dB Gain, 50 Ohm input impedance, AC input
- SPA.1801: 2 GHz bandiwtdh, 20 dB Gain, 50 Ohm input impedance, AC input
- SPA.1601: 500 MHz bandwidth, 20 dB Gain, 50 Ohm input impedance
- SPA.1412: 200 MHz bandwidth, 20/40 dB Gain, 1 MOhm input impedance
- SPA.1411: 200 MHz bandwidth, 20/40 dB Gain, 50 Ohm input impedance
- SPA.1232: 10 MHz bandwidth, 40/60 dB Gain, 1 MOhm input impedance
- SPA.1231: 10 MHz bandwidth, 40/60 dB Gain, 50 Ohm input impedance
This is an add-on product for Spectrum's own line of instrumentation product. This product is therefore solely sold together with one of these and not separately.