Tower Top LNAs

DCI tower-top amplifiers achieve excellent sensitivity by using very efficient LNAs while maintaining better-than-average intermod immunity through the use of very sharp, low-loss filtering. Each unit consists of a low-loss filter and low-noise amplifier, a transfer switch, and lightning protection on both the input and output coax. The units are housed in a weatherproof aluminum enclosure that bolts to the tower leg.

• The units are powered via 12 volts through the coax.
• The transfer switch allows you to use the antenna in the event of an LNA failure.
• The selective filter ahead of the LNA eliminates all signals except the wanted in-band signals. This configuration allows us to use a much lower noise figure in the LNA and greatly reduces the possibility of intermod.
• Most other commercial LNAs are biased for intermod immunity and achieve an intercept point of about +35 dBm, but this increases the noise figure up to 4 dB.
• The LNAs we use have a typical noise figure of 0.6 dB with a 3rd order intercept point of about 27 dBm.

Tower Top LNA Examples