this is my varna

[mesy64]

hi to all
this is my varna t/r
but this detector have low depth detect .i want high depth .please help me

[technos]

This sounds like a coil problem imho. Hi - If it was me, I'd make sure that my coils resonated (are tuned) to the exact same frequencies and nulled (as the thread on two box detectors talks about). I would bet that helps with depth considerably.

BTW - good job on the circuit boards.

[mesy64]

TANK YOU
I WIND 100TURN WIRE NUMBER 0.30 IN 27*33CM.
BUT WITH COIL HAVE VERY LOW DEPTH DETECT.WHITOUT SHILD.
WHIT SHILD HAVE VERY VERY LOW
PLEASE HELP ME FOR HIGHT DEPTH

[BigBang]

TANK YOU
I WIND 100TURN WIRE NUMBER 0.30 IN 27*33CM.
BUT WITH COIL HAVE VERY LOW DEPTH DETECT.WHITOUT SHILD.
WHIT SHILD HAVE VERY VERY LOW
PLEASE HELP ME FOR HIGHT DEPTH

Before shielding you can wind transmitter coil with 0.50 or 0.60 wire number.It consumes battery faster than this one because of high current . However it may be enough for your utility.

Usually shielding is using for receiver coils against electrical and natural noises .If you filter the noise with your filters in your circuit , shielding is not a must.

[detectoman]

mesy64: you can increse very much the sensitivity, whit put capacitores of ceramic, but those are hig inestable in sun warm, but ideal in time cold, may be should put cap, yellow tipe egg in any step, major green cap, too change the transistores by others of most gain, or most power, tipe bc b, o c, but these can drift then whit hot my congratulations for these cool pcb one embrace

[technos]

deleted double post

[technos]

Usually shielding is using for receiver coils against electrical and natural noises .If you filter the noise with your filters in your circuit , shielding is not a must.

I would not add shielding until the detector worked on the bench. The need for shielding takes place if you are moving your coil through a lot of grass, as you need to have a shield drain of the charge caused by the extra capacitance/interaction with the grass. With a large two box TR detector such as this esp. if it is sitting at hip length as you use it, you would not need one.

I also think some of the shielding recommendations around such as covering the coil with heavy metal tape is excessive and most likely detrimental. Also note with a heavy shield in place, you have a not insignificant 3%+ performance degradation that takes place (With Mesy64's detector it seems to be even more).

With Mesy64's detector, I'd leave the shield off, find the frequency/inductance of his coils, and from that adjust the resonance of his receive coil. Get it working good before putting the shield on, or leave it off entirely.