The design of very wideband amplifiers using transistor feedback pairs is discussed in detail, and typical experimental results are given. With source and load impedances of 50Ω, the product of gain and bandwidth is nearly 2000 MHz for a single pair, and over 10000 MHz for two pairs in cascade, subject to a maximum bandwidth of about 400 MHz. Noise factors range from 2 to 6dB. Source impedances other than 50Ω can be used.