Ну что, друзья, мои исследования и письма Хансу о кликах в QCX mini прошли не зря =)
Вышла новая версия платы REV3, где уже есть RC фильтр для энкодера и конденсаторы на землю для манипулятора (ключа) от наводок во время передачи.
Из нового мануала =)
The paddle inputs, and the rotary encoder switch, are read using dedicated microcontroller I/O signals. In PCB Rev 3, the paddle inputs each have a 1nF capacitor to ground, whose purpose is to get rid of any stray RF that may have been picked up on the paddle cable.
Note that in PCB Rev 3, there are additional R-C filters on the ROT A and ROT B signals containing a series 10K resistor and 10nF capacitor to ground; these are shown on the schematic of the whole front panel board. The purposes of these filters is to suppress clicks that occur on tuning. The clicks are at a low level and not normally audible except on dummy load (on an antenna, the band noise normally masks the clicks). The exact origin of these clicks is unclear and they do not occur on the QCX+ and QCX-classic. Tests were undertaken that prove the clicks do not arise due to microphony and neither are they due to a PCB layout issue. Anyway, the R-C filtering attenuates them greatly.
Форум 
