In my previous post I mentioned that the hardware filtering of the rotary encoder had improved the reliability, but occasionally I would still get inconsistent results, especially when turning the knob quickly.
Rotary Encoder Contact Bounce on ubitx
Unfortunately, after a while the reliability got worse again. I suspected either dirty contacts or a faulty rotary encoder.
I squirted a load of switch cleaner/lubricant (Servisol Super 10) into the gaps in the housing and rotated the encoder a few times. After allowing time for it to drain/dry I switched on the radio and tried tuning it with the rotary encoder. It worked flawlessly.
ConclusionsNo amount of filtering will fix a faulty rotary encoder, or one with dirty contacts.
However, I still recommend using adequate wetting current and applying some filtering, either in hardware or software (refer to original article). Any mechanical rotary encoder with exhibit some degree of contact bounce/chatter and operating the contacts at very low currents will make them less reliable.
If I get any more problems with the rotary encoder I think I shall be replacing it.