Two-stage UHF antenna preamplifier

How it works

A band-pass input network selects the intended UHF region. Two common-emitter stages then raise the signal level before it reaches the receiving equipment. The archive describes a nominal gain of 21 dB.

A preamplifier raises noise and unwanted signals as well as the wanted signal. Strong local transmissions can overload it or the receiver; more gain does not always improve reception.

On the bench

Use a compact RF layout and a grounded metal enclosure. Measure gain and stability with the intended cables and receiver, and check whether strong-signal interference increases.

Resources & provenance

Rewritten from the original circuits/rfr/hg65q0p_rfr009.php page. Component values and historical performance claims have not been independently bench-tested. The circuit figures have had their watermarks removed.