So now it is time to bless the world with your new found keying ability. To do this,
we gotta hook it to your rig. Most modern rigs require a circuit that drives the
key center pin to ground. Little current is normally required, but I have
put in a heavy duty higher voltage transistor to be on the safe side. You
should be able to drive a relay with no problem. If you do this, dont forget
the shunt diode to kill inductive induced spikes. Once again, a .01mfd cap
is included to help kill RFI emissions.
Install Q2 2N2222
Install R12 33 ohm connect from Q2-emitter to GND
Install R13 4.7K connect from Q2-base to +5V
Install R14 820 ohms connect from Q2-collector to +5V
Install C4 (.01) between Q2-base and GND
Install D1. Connect - end (without band) to Q2-base
Connect + (band end) of D1 to 87c750-22
Install Q3 2N3019
Install D2. Connect - end (without band) to Q2-collector
Connect + (band end) of D2 to Q3-base
Install R15 100 ohm 1/2 watt. Connect from Q3-emitter to GND.
Install D3 with the + end (band) to Q3 - collector and the other end to GND
Install C6 .01 in parallel with D3.
Temporarily install an extra 220 ohm resistor and LED between +5V and the Collector of Q3 to provide a test indicator.
Power up the circuit again and check that the LED lights when code is being sent.
Note: You must remove the test LED and resistor before attaching to your rig.
