The QB-840 from Spectrum Control is a RF Amplifier with Frequency 800 MHz to 2.2 GHz, Gain 11 dB, Small Signal Gain 10 to 11 dB pk-pk, Gain Flatness ±0.25 to ±0.60 dB, Noise Figure 6.5 to 7.5 dB. Tags: Driver Amplifier. More details for QB-840 can be seen below.