Quote:
Originally Posted by toorani
Hello dear franco
I hope you always be healthy
I found the problem circuit,Tr2 transistor was faulty.
The collector voltage is now: tr2 2.8 volt ,tr3 4.5 volt, tr4 4.5 volt
why the collector voltage tr2 is 2.8 volt?
Without the quartz, the output voltage is zero(emiter tr5) and with quartz is 4.1 volt
signal Emitter tr1 is 8 Mhz 2.4 volt pic to pic,Of course capacitor c1 is Two parallel capacitors 560p.
capacitor c13 is 200 nf and c14 is 100 nf but why The output voltage does not exceed 4.1 volts?
capacitor c2,c3 and c4 is 1.8 pf
Thank you very much for your guide
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4.1V is ok. 2.8V at TR2 collector voltage is ok, as here the signal is very small. If touching
the antenna the output changes the sensor stage is ok.