Basic Equalizer Connections

Basic Equalizer Sound Card / Transceiver Connections

For receiving, if using a commercial sound card interface for receive, do what you normally do to hear your transceiver's audio through
your computer speakers.

For transmitting, if using a commercial sound card interface, cable your microphone to the microphone input of the sound card, and
ensure the speaker output of the sound card is routed the the microphone input of the transceiver when you press your PTT
arrangement.

You may just wire the sound card output to the microphone in on the radio with an isolation transformer, if you do not need to use the sound card output for other computer tasks.

An inexpensive and good isolation transformer is available at BuxComm.com model number XFMR115. This transformer has a good low end frequency response down to 75 Hz at -6 dBv. W2IHY has a ready built audio interface unit that may be used to interface your sound card to your radio. I-Box from W2IHY

Interface that switches speakers and keys radio.