Kenwood Hybrid Tune-Up Procedure
by Ken, K4EAA
http://www.k4eaa.com/tune-up.htmHere are some instructions for how to properly tune your Kenwood hybrid transmitter. It takes longer to describe than it does to actually tune the rig! When you have done it a few times, you can tune up in about 5 seconds total, faster than it took you to read this paragraph!
1. Begin tuning with the Mode Switch in the Tune position. That reduces the screen voltage, and mis-tuning won't harm the rig. Start with a dummy load if possible.
2. Set the Load Control to Minimum, and dial in the band (approximately) on the Plate control
3. Set the Meter Switch to ALC
4. Turn the CAR Control (carrier) up 1/2-3/4
5. Place one hand on the Send switch and the other on the Drive control
6. Flip the Send switch and peak the Drive control. If the meter pegs, turn down the CAR control and peak Drive again.
7. Switch Meter to Ip (plate current)
8. Flip Send switch and tune the Plate tuning to dip the Meter (minimum reading). This is usually the max power output point as well.
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Now you're ready to go for some power! As you perform the steps below, don't leave the rig in Send more than 5 seconds at a time. Give it a rest now & again as you get familiar with this. Most of us can tune a rig in about 5 seconds total, you will too when you've done it a few times!
1. Switch Mode to CW
2. Flip the Send switch and re-dip the Meter with the Plate control
3. Note the Meter reading - You are looking for about 225ma, depending on your power needs - About 1/3 to 1/2 less for PSK or RTTY
4. It will probably be low. Turn up the Load control about 10 degrees, and re-dip the Plate control. Continue doing this until you get about 225ma of plate current when dipped. Remember not to leave the rig in Send too long while you're learning, give it a 5 second rest every 5 seconds.
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You're almost finished! Transmitting at this point would be fine, but you may be able to tune for a bit more power. The next adjustments should be small adjustments, you are "fine tuning" things at this point.
1. Switch your Meter to RF, or use an external power meter for reference.
2. Tune the Plate control for maximum power output. You should see about 100W if you have a power meter.
3. Try adjusting the Load up or down a bit, re-peaking with the Plate tuning after every adjustment.
4. When you're satisfied with your tune-up, check Ip, the plate current, and make sure you're not too far from the 225ma target, and note the position of the controls to use this as a starting point whenever you return to this band.
5. For CW, use the CAR control, and for SSB, use the MIC control to keep the ALC within the range shown on the Meter. This will insure maximum power output without excessive compression.
