Serbian "Most Wanted"

[rdec4]

That's really good question! I also asked my self that!!?
It had role of "Sense" in 1265 design.
Right here it does not have any important role. It can be omitted.
Yet i included it on my pcb and tested audio behavior when adjusting that trimmer. It makes some slice difference - not a big deal.
With or without it - not a big deal...
I just being smart as* and named it "Bias"...to daze the enemies!!!

ivconic thank you for your response . I have another question. Potentiometer "Threshold" as a specifically threshold level, is or not dependent on potentiometer "Sense"?

[ivconic]

ivconic thank you for your response . I have another question. Potentiometer "Threshold" as a specifically threshold level, is or not dependent on potentiometer "Sense"?

As i noticed; not.
BTW that treshold preset is most interesting feature to experiment with. Whole quality of final audio output directly depends on treshold adjustment (as i experienced).
That treshold feature is main reason why i replaced old audio stage with this one.

[rdec4]

As i noticed; not.
BTW that treshold preset is most interesting feature to experiment with. Whole quality of final audio output directly depends on treshold adjustment (as i experienced).
That treshold feature is main reason why i replaced old audio stage with this one.

ivconic thank you again .

[night]

hi ivconic good project thanks What is the voltage regulator u7 is 7805 our 7809 schematic 7805 layot is 7809? Which is true? and which better performance tgsl 1265 our SMW

[ivconic]

hi ivconic good project thanks What is the voltage regulator u7 is 7805 our 7809 schematic 7805 layot is 7809? Which is true? and which better performance tgsl 1265 our SMW

Both. 7809=9V, 7805+ZD4V7=9.7V. I put 7805+ZD4V7.

Which better? Read previous posts.

TGSL = Extra accurate Disc, Stable, Descent depths.
SMW = Average Disc, Stable, Extra depths.

Both are very good and both are low budget, good for DIY.

[Magma]

Coil

The data for the coils DD 27-28:
TX - 75 windings, 0.45mm wire, diameter 200mm.
RX - 160 windings, 0.27mm wire, diameter 200mm.
Tested on more than 60 performed detectors.

[Magma]

Design of my first "Caesar", made 2001.

[WM6]

The data for the coils DD 27-28:
TX - 75 windings, 0.45mm wire, diameter 200mm.
RX - 160 windings, 0.27mm wire, diameter 200mm.
Tested on more than 60 performed detectors.

Thanks. What are yours measured inductances?

[Geo]

Hi Ivconic.
I see some differences betwen the 2(your) schematics and the original one.

So R24 and R26 is 1M3 or 2M2???
R28 at PCB is 4k7 not 1K.
C14 and C16 at Prototype are 1n and at your are 1uF.
Please can you tell me what you are use???


Regards

[Qiaozhi]

Design of my first "Caesar", made 2001.

Please can you tell me where you bought the stem, arm rest and coil housings?

[Magma]

Thanks. What are yours measured inductances?

Rx-11.8mH
Tx~2.6mH

[Magma]

Please can you tell me where you bought the stem, arm rest and coil housings?

The stem is made of aluminum handle for painting and arm rest of PVC pipe 110mm (or aluminum plate) , coil housings I was bought in Bulgaria.

[Qiaozhi]

The stem is made of aluminum handle for painting and arm rest of PVC pipe 110mm (or aluminum plate) , coil housings I was bought in Bulgaria.

Interesting. It is difficult to see the detail from the photo, so I assumed it was being manufactured locally. Nice job!

[WM6]

Design of my first "Caesar", made 2001.

What is this, battery department or pin-pointer?

[Magma]

I recommend this rezistor as protection against hypersensitivity.