Re: QCX and peaking BPF


Liam Kingsmill <lumetters1@...>
 

Daniel, I've noticed the microphonics you describe below. Tapping different places on the PCB seemed to narrow the most microphonic to the area around IC9 and IC10.

But, other issues were solved by Canada Glen who designed a workaround allowing the receiver to work quite close to what we believe was Hans' design goal.  The workaround bypasses half of IC9.

The oddest issue remains:  Starting the QCX requires a certain power switch contact bounce.  To get the QCX working can require between 1 and 20 power OFF/ON's.

That odd behavior has been mentioned by me twice before in posts here.  Since there have been no comments, it appears the issue is peculiar to # 3171.

Thank you, Glen.  Without your input I'd own a dud.

Liam

On 04/02/2018 07:01 PM, Daniel Urbach wrote:
has anyone else noted that the board is a bit "microphonic" ...in that moving the board about on the bench produces sounds in the headphones ?

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