Crappy components ruin the good work and wastes so much good time…
I lost hours because of the auto manual switch as it was crappy one and had bad contacts… maybe bad soldering in the past without flux… component substituted and now the scanning work with no flaw
Now a long way testing…
I’m going to make a follow test with the frequency gen in the feedback to see if it locks and follow if in the range and how the filter behave the multi switch is including 500ohms in series when switched on… that may be because it’s working on 5 v
The correct part would be one for 5v but I haven’t it here
Anyway it already seem to be switching when in lock so it may not be a big problem to have this 500ohm between the filter and pin 9 as it may compensate anyway…
1 de maio de 2023
https://youtu.be/mr51EOeiJnE1 de maio de 2023
https://youtu.be/wM2rFm5TU141 de maio de 2023
https://youtu.be/guxL6m_K2ncThe quad bilateral switch should be HCT 4066 instead of cd4016 that I’m using… this hct part has low on resistance and is faster is designed to work at 5v max… so is perfect for this board… if I notice some voltage across it during operation I may substitute it as it may be cause difference with the loop… supposedly the pin 9 has a high impedance input but who knows… the voltage across it will tell the current consumption from the pin 9
Also I added some 10nf capacitors at the trim going in the non inverting input and also at the output…just to clean up a bit
I than may use the other opamp in the lm358 for voltage follower of the output of the first so there no chance for the pin9 impedance to interfere on the scanning ckt… hopefully I can get a better voltage range regulation at least and maybe cleanup the small negative spike coming randomly