Re: QCX-Mini 40m – low audio and odd IC9 voltages


howard winwood G4GPF
 

not necessarily so, I would suggest going through the alignment process again, follow Hans instruction and video to the letter, before blaming the components. 
the bandwidth is very small and needs accurate setting of the 3 pre set potentiometers to get the signal through.

Just a suggestion……….

On 24 Mar 2021, at 14:20, Ronald Taylor <wa7gil@...> wrote:

Doug, the symptoms you are indicating point toward a possible issue with the last stage of amplification (IC10A). That's based on the fact that you seem to have good levels at the "Audio 1" measurement point that comes from the first stage output of IC10B. If voltages on pins 1,2&3 are good (roughly half the supply voltage), check first C51and continuity from it to IC10 pin 1 and to the headphone jack. IF the cap is good and all connections good, then you may end up replacing IC10 even though the voltages look good. Good luck ... Ron

On Wed, Mar 24, 2021 at 7:00 AM <kb8m@...> wrote:
Greetings.
I too am having low audio issues. My voltage readings are on par with what you've discussed.  I am, however, able to adjust BPF to about 8, and all my alignment adjustments do change.  Depending on how I start with the IQ-Bal, some of my adjustments can go from 8 to 0...   Is that ok?  Although I am getting low volume, If I strain I can pick out average stations, and if a station is very strong it comes through at an audible, albeit low, volume level.  I did connect to an antenna last night and worked Oregon from S. Michigan.  Also the RBN shows my freqs are correct.  Any help with the volume issue would be appreciated.

Doug KB8M



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