Lrl from Italy

[Jeg]

Hi friend
Looks like something is wrong, but wait for Franco to tell his opinion as he is very experienced on this.


(try connecting your voltmeter at the output of your sensor. When you touch the antenna, does the output signal drops?)

[FrancoItaly]

Originally Posted by Jeg

Hi friend
Looks like something is wrong, but wait for Franco to tell his opinion as he is very experienced on this.


(try connecting your voltmeter at the output of your sensor. When you touch the antenna, does the output signal drops?)

Yes, otherwise it could mean that there is a self oscillation. By touching the antenna a part of the signal on the base of TR2 (the mixer) is absorbed by the body and therefore the signal amplified by the sensor stage decreases slightly.

[JHERICKU]

hello friend franco,Should I connect the negative probe of the multimeter to ground and the positive one to antenna to get the reading or the positive probe to transistor 04 emitter ?

I am so sorry..I have few knowledge about electronics..My apologies..

[FrancoItaly]

Originally Posted by JHERICKU

hello friend franco,Should I connect the negative probe of the multimeter to ground and the positive one to antenna to get the reading or the positive probe to transistor 04 emitter ?

I am so sorry..I have few knowledge about electronics..My apologies..

The negative probe of the multimeter to ground and the positive to transistor 04 emitter.

[JHERICKU]

Originally Posted by FrancoItaly

The negative probe of the multimeter to ground and the positive to transistor 04 emitter.

I got 1.5 volts on transistor04 emitter with the trimmer on maximum..I have noticed that it beeps when I touched the board or the potentiometer and the antenna but the output not dropping..I believed the antenna is on positive line.It gives me 12v measurement..

[JHERICKU]

I remove the quartz and I got .044 volts on output..Can anyone have idea especially to franco if I got the correct output?
ps.I used 4mhz quartz..
Thank u for suggestions in advance..

[Rubin]

I would like to know who knows or has tested, if the franko circuit can detect nuggets.
I ask, because i have many signals from a place and i find only small nuggets.
I am comfused

[FrancoItaly]

Originally Posted by JHERICKU

I remove the quartz and I got .044 volts on output..Can anyone have idea especially to franco if I got the correct output?
ps.I used 4mhz quartz..
Thank u for suggestions in advance..

The sensor stage output measurement is on the emitter of TR5, not TR4.

[JHERICKU]

Originally Posted by Jeg

Hi friend
Looks like something is wrong, but wait for Franco to tell his opinion as he is very experienced on this.


(try connecting your voltmeter at the output of your sensor. When you touch the antenna, does the output signal drops?)

I do not know where to put the test probe to measure the voltage..I have have no idea if it is droping or not..

This time I change te 10k potentiometer with 25k and remove the sensor stage for a while but there is no buzz and led ligths at all..I have noticed that when I touched everywhere on the board the led and buzzer beeps also..I think it is grounded..
Any suggestions my friend..

[FrancoItaly]

Originally Posted by JHERICKU

I do not know where to put the test probe to measure the voltage..I have have no idea if it is droping or not..

This time I change te 10k potentiometer with 25k and remove the sensor stage for a while but there is no buzz and led ligths at all..I have noticed that when I touched everywhere on the board the led and buzzer beeps also..I think it is grounded..
Any suggestions my friend..

The point to be measured is the output of the sensor stage, the one that goes to the input of the display stage. For the rest I don't know what to say, check the assembly carefully, maybe you made some mistakes.

[JHERICKU]

Originally Posted by FrancoItaly

The point to be measured is the output of the sensor stage, the one that goes to the input of the display stage. For the rest I don't know what to say, check the assembly carefully, maybe you made some mistakes.

I put the probe on sensor output and I got 4.+volts. I touched the antenna and the voltage is thesame..why should I do?