SKC - SIMPLE KEYER CHIP

Here is a simple iambic keyer chip that costs only $2.00. Only a handful of components needed to build a complete keyer.

The SKC is designed to provide basic keyer functions for simple qrp rigs. It is particularly useful in Direct Conversion rigs, as it provides a means of generating side tone. Separate outputs for audio mute and transmitter keying provide sequenced audio muting and oscillator shift, allowing these to happen before and after the transmitter is keyed. This eliminates the need for R/C time constants in the auido mute switch(es) in the rig.

When not active, the keyer is in a low power sleep mode. While "asleep" the chip draws just a few microamps. This not only reduces current comsumption when the keyer is not being used, it keeps the internal oscillator from being heard in the receiver section of the rig its installed into. Sleep mode was added to chips shipped after 6/1/06.

more at http://kd1jv.qrpradio.com/skc/SKC.HTM