Lrl from Italy

[Zicos]

what is the mistake i am doing?

[Zicos]

the calibration should be done with:"1"(piece of copper wire or with telescopic antenna,?)and the result should be 0volt without crystal,"2"(the length should be 30-40cm, not less or bigger?)

[FrancoItaly]

For convenience, the calibration is done with a piece of wire instead of the antenna, but it could also be done with the antenna as long as it is placed about 10 cm from L1. The length of the antenna, during calibration, is 40 cm, but you can vary it and see the result. Honestly, I've never measured the piece of wire, I use a connector with two crocodiles and I measured it now, it's 40cm.
These values are indicative, unfortunately the sensor stage is very critical and it is important to obtain maximum gain because the "phenomenon" has a very small amplitude.

[Zicos]

thank you very much..will try it and let you know.

[Zicos]

good morning Mr. Franco. and to the children of the forum. so I tried it as I calibrated it with the antenna open 97 cm and without a crystal 0 volts. and with a crystal 5.04 volts. it did not catch the signal in the garden.. is there any chance that the display is to blame??? (3led p1 22k -p2 500k -p3 10k)

[Zicos]

how can i upload photos????

[FrancoItaly]

how can i upload photos????

Select " Attachmens "

[Zicos]

where is Attachments?

[FrancoItaly]

On the page where you write your post, at the top, in the center, next to the Smiles.

[Zicos]

this piece of copper wire is used by you Mr. Franco to calibrate???

[Zicos]

I also calibrated with this copper wire that you see in the photo and I understood that the volts go to 0 without a crystal as soon as you turn it in another direction it gets volts again. how should I calibrate??? I think the translation doesn't let me understand what do you want to tell me..

[FrancoItaly]

I also calibrated with this copper wire that you see in the photo and I understood that the volts go to 0 without a crystal as soon as you turn it in another direction it gets volts again. how should I calibrate??? I think the translation doesn't let me understand what do you want to tell me..

Inside houses there are many RF signals, the sensor stage with an antenna at the input can definitely detect these signals. The only thing different from you is that you use a rigid piece of copper while I use a flexible wire and that you move the antenna to different positions. Leave the wire in the same position and touch it only to check if the signal decreases (once the oscillator is connected).

[Zicos]

hello mr franco.thank you very much for helping me. i found the problem. for power supply use a 13.5 volt power supply and then i connect a step down for 12 volt. as soon as I put the power supply with 13.5 volts without the step down the problem was solved.. in the garden test and in the field I used a 18650 battery with a step up to have 12 volts. that must be the problem.. but the signal in the garden was very good and clear... as i had it before but in the field nothing is heard. i will do the circuit with the 78012 and see what happens... again thanks a lot.

[FrancoItaly]

The 7812 IC needs at least 15V input to stabilize correctly, otherwise a low drop IC can be used. I use two 9V batteries in series so that the absorption of all the LRL is around tens of milliamps.

[Zicos]

the 9 volt batteries should be simple or do the rechargeable 9 volt ones as well?????