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QCX key click/thump


Steve in Okinawa
 

I've been testing combinations of different earbuds and sidetone volume and am satisfied when using semi-QSK. But now the "full QSK" click is intolerable. What's the latest guidance on reducing this, also described as a thump?
Thanks in advance. JS6TMW


Arv Evans
 

Steve

I would look through the schematic to see where quiescent voltage changes when switching 
modes.  Coupling capacitors do take time to change voltage between operation modes.

Arv
_._


On Mon, Apr 20, 2020 at 12:50 PM Steve in Okinawa <sfab43@...> wrote:
I've been testing combinations of different earbuds and sidetone volume and am satisfied when using semi-QSK. But now the "full QSK" click is intolerable. What's the latest guidance on reducing this, also described as a thump?
Thanks in advance.  JS6TMW





w2eck
 

I have experienced the same loud "thump" key clicking in my 40M QCX

73
Paul
w2eck


Steve in Okinawa
 

Paul, the thump has been commented on many times here, and several fixes suggested. Being innately lazy, I am hoping someone can point us to the quick and easy solution. 73, Steve


g4edg
 

Hi

Please see my recent post regarding increasing C24 from 10uF to 100uF to stabilise the voltage at pin 5 of IC10. If your board is an older one check the values you have fitted at C21/22, latest kits have 1uF fitted.

With these mods my QCX has near perfect click/thump full QSK.

73 Steve G4EDG


g4edg
 

That should have been "click/thump FREE full QSK" !


Denis DL5SFC
 

Hi to all.
This works perfect!. After adding a 100µF in parallel to C24 the click noise  disapear at low volume Level completely and at higher Level barely noticable.
I have also replaced C21/C21 by 1µF high quality polyester capacitors from WIMA.

Thank you Steve.

vy 73 Denis 

DL5SFC