IDX-PRO+VDI

[medj]

I have a problem that it works but Poor 5 cm
I want to ask any pieces that controls the detection distance
After finishing it I promise you that Post all the details of the device industry
I'm with him in the period of 6 months and will hope to Create Detector
Thank you

[Koala]

Had a good look at the board can't find any shorts. Checked the value of caps and resistors. Forgot to mention I am using BCX38C for MPSA13 and BC237 for BC547 and for one of the LM358 I am using a LM258. It's so close to working properly.

[Koala]

Made some progress. The idiot I am I place a resistor in place of C4. The silkscreen was patchy over the letters but it was clearly the bigger square. Don't know how I did it but I have change it. Now my disc mode is now not quite as good as it was but the all metal mode is a better. Added a resistor to the ground pot and I can balance the ground out 32K. This has fetched the distance of the disc mode to 95% of what it was. All metal mode can almost match this but only on head phones volume is very loud when close to the coil but drops of very very quickly and is only very faint for the last 5". Any ideas which part of the circuit I should be looking at.

[Koala]

Need to sort out all-metal mode first then it will never get nervous as is only working to about 4" UK copper 2p coin
I swopped U5 and U6 over no difference.
Same coin in disc mode I get 10" easy and a bit more with a broken iron signal with a 8" coil so well pleased with this

[Davor]

You are supposed to tune the VR4 to a position where all-metal mode becomes "nervous" and you'll get plenty of depth.

[Koala]

Took the sens pot off and measured with a multi meter everything was fine. Reconnected and now get an extra 1" when wound all the way up but the tone is broken is the correct. Pin pointing seems to be working small amount motion needed.

Distance in all metal mode is still poor. about 1/3 of the disc mode.

[Koala]

Hi I need some help please I have built a silverdog board and have a few small problems. I am testing with a factory coil.
Detection range in Disc mode is okay. Discrimination is working okay.
Detection range in all metal is about 1/3 of Disc mode
Threshold pot works in all metal mode but has no affect in Disc mode is this normal
Sens pot does nothing. Makes no difference if you disconnect it. Same in both modes
Ground balance has to be wound all the way over is this because I am using a 20K pot instead of a 22K
I have a scope and a multi meter.

[Fabian]

Hello. My detector is working properly on the bench. Good discrimination, good balance of ground. The DD coils work great, 37 cm in disc mode. The capacitor 24 should be 100pf, not 100nf ...
Now, I will try with CC coils.

Regards,

Fabián

[skyline25]

Hello what program can convert pcb schematic schematic VDI-led pcb I want to do, has anyone pcb for her

[ashefr10]

hello, I have not altered and have not put resistance 4k7 my r25 is 47 ohms and I have no problem of stability, the only problems I had two mistakes resistance value if everything was ok.

may be you have a problem with balancing your coils if you built the same head

[seadoggy]

it comes from classical pcb without modification

do you remove R25 resistor and add 4k7 resistor between pins 6 and 7 of U4 (LM393)??
i have problems in discrimination mode like you before MD is not stable to much noise!!my R25 is 47 ohms!!i must turn trash hold to "0" to be stable but i lose depth.

[ashefr10]

Is your PCB Modificate or its is normal PCB whit out any changes??

it comes from classical pcb without modification

[seadoggy]

here is the 3rd re-encoded video, it was of poor quality on youtube.

Is your PCB Modificate or its is normal PCB whit out any changes??

[tonyh]

OK , for DD 27 cm (10 inch)

TX : 34 turns diamètre 0,6 mm with the capa 1 µf > 1,7 ohms > 0,59 mH

RX : 260 turns diamètre 0,2 mmet with capa 47nf > 90,4 ohms > 34 mH

thanks, it gives me something to aim for when I build my IDX

[ashefr10]

can you give some construction details, wire thickness, number of turns, inductance etc. thank you.

OK , for DD 27 cm (10 inch)

TX : 34 turns diamètre 0,6 mm with the capa 1 µf > 1,7 ohms > 0,59 mH

RX : 260 turns diamètre 0,2 mmet with capa 47nf > 90,4 ohms > 34 mH