CW key sticking with Nextion LCD


Joe Puma
 

I recently installed the 5” Nextion on uBitx Rig. I noticed that on the 10 meter band the CW key sticks when pressed and there is a noisy tone that goes along worn it. I guess this is RF getting in the line. If I disconnect LCD from power it goes away. I’ve been trying out .1 uf caps on things I seem to be having RAF issues with and it’s been fixing it with great success. So for the keyer I put a cap over the blue wire going to LCD and ground. It stopped the sticky CW key and I don’t hear the squealing RF in the signal.

Now on 18mhz when I key the CW keyer I hear some hiss when I unkey during that delay time which is 600ms. I also see other weird things that happens during that 600ms delay. When RF was getting in even though it didn’t make the key stick during that delay time, my power and swr goes up briefly. I can make the delay be 0 and be done with it. I only use the CW keyer to trigger my auto tuner so I don’t need the delay but that odd surge in power and swr makes my auto tuner retune after I let go of the CW keyer. It makes using it a tuner tigger useless.

Normally during that delay you dont see any signal but if there is RF in the chain it seems to discharge it back out onto the antenna port during that delay process. This causes the auto tuner to tune.

I’ve only noticed it with the 5” LCD installed.

Jow
KD2NFC

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