To make sure that you are receiving the very best results from your system it is a common practice to install some kind of pre-amplifier ahead of the RX, this will provide the front end with additional gain, but will also make up for any losses that are occurring in your feeder cables. Some stations go to the length of installing the pre-amp at mast head, if you decide to do this then make sure that it can be properly water proofed.

You may also have to devise some kind of TX/RX switching system such as a coaxial relay. Perhaps a slightly cheaper method is to install two aerials, one for the receiver and another for the transmitter.

The Camtech low noise pre-amplifier stage.

This design by Camtech Electronics dates from around 1986 and is based on two N.E.C NE02136 bipolar transistors. Matching of the transistors between input, output and interstage is achieved by extensive use of microstriplines with bias being applied by quarter wave transformers. The gain of this design is typically 14dB with a noise figure of less than 2dB.

The G4BVK Gasfet pre-amplifier.

The ULNA 23-4 by AZTEX Electronics designed & constructed by Ken Stevens G4BVK on the other hand uses a very good Gas-FET device the ATF10135 which gives it a useful gain of 17db at 23/24cms, with a very low noise figure of only 1db. This pre-amp also has a broadcast band filter to help reduce interference from terrestrial television signals. Unfortunately these are no longer available new, but may occasionally be found on the specialist second-hand market or at radio rallies.