Ham Radio Forum

I heard some HAM can use two antennas and transceivers in same time. So they can monitor frequency for someone break-in or QRM, etc. Does anyone know how they work? I think if antenna receive a strong signal and put into receiver, maybe the receiver will overload and damaged. Thanks a lot and excuse for my syntax mistakes.

73!

As you point out a secondary antenna close to the transmitting antenna may deliver a damaging signal to the second receiver. This can be avoided by locating the receiving antenna a sufficient distance from the transmitting antenna to reduce the received signal to an acceptably low signal level. Also, a well shielded resistive attenuator could be used between the secondary antenna and the receiver to further reduce the received signal.

This can be done more easily with systems using separate transmitter and receiver. This was common when I was first licensed in 1949 and years following. On inexpensive modern transceivers the input to the receiver section is not normally available and the receiver front end may be disabled when in the transmit mode. Also, to reduce production costs some of the circuitry is shared between the receiver and transmitter sections and cannot be used for both purposes simultaneously.

Hope this helps.

Jess, w4pqk