Serbian "Most Wanted"

[Pompey]

Air tests with 555 SMW version with 27DD:

24mm coin - 45sm
34mm coin -55sm
diskr -rejects all iron
no reaction to ferrite
very small sound cracks coused by interference
GEB must be adjusted very fine to get best sensitivity and stability.Also coil nulled perfect.

[WM6]

What was the coil you were using?

I was not there. They inform me that it was Excellerator dia 32 cm DD coil (intended for Fisher 12xx series).

[technos]

Here some video scene on general SMW phase and sens test. SMW was build according ivconic mod. Video taken by Tragac (member Serbian MD forum) using mobile phone (so not the best quality of tone repro).

http://www.youtube.com/watch?v=ezmUjCj5nss

What was the coil you were using?

[WM6]

SMW phase test

Here some video scene on general SMW phase and sense test. SMW was build according ivconic mod. Video taken by Tragac (member Serbian MD forum) using mobile phone (so not the best quality of tone/video repro).

http://www.youtube.com/watch?v=ezmUjCj5nss

[Geo]

Hi Geo
What is your final solution for the phase with the coil BM 1600?

Hi Vladimir.
I correct the phase shift of the coil by adding the 10nf capacitor in series with the Tx signal and the 22k potentiometer as at the schematic that i posted here

Regards

[Vladimir]

Yes, but is not comfortable. It is heavy
Maybe today to try a Blumax 950!!!

Hi Geo
What is your final solution for the phase with the coil BM 1600?

[Geo]

Yes, but is not comfortable. It is heavy
Maybe today to try a Blumax 950!!!

[technos]

I finished my Caesar with the BlueMax 1500. The detector is very good at air test,

Of course, using a monster coil always helps too!

[Geo]

I finished my Caesar with the BlueMax 1500. The detector is very good at air test, but i must make a really test when the weather will calm.
I put the detector inside a box of a MD5002. All ok but the coil is very heavy for this box so when i move the detector i hear always some krik.... krak... etc from the bad plastics. If i will keep it, i must replace the box with the arm.


Regards

[Geo]

I shorted C26.Now sound is good .34mm coin detects at 45sm in air with 38DD in discrimination.A very good machine.I want now to make a concentric coil.Any sugestions how many turns L1 L2 and cancel coil? Housing is 24sm. so outer diameter is 24sm and inner -9sm.

With 38cm coil you must detect the 34mm coil at least at 50cm. Check the tunung of the coil!!!

[Pompey]

I shorted C26.Now sound is good .34mm coin detects at 45sm in air with 38DD in discrimination.A very good machine.I want now to make a concentric coil.Any sugestions how many turns L1 L2 and cancel coil? Housing is 24sm. so outer diameter is 24sm and inner -9sm.

[technos]

Hi,Geo,I already tried different caps.Yes the sound become more beautiful if you put 7-8nf instead of 10.But it seems to me like the depth goes less with changing sound to high frequency.

I think if you want better sound you need to change the square wave osc. and find a sine osc. imho.

[Pompey]

Hi pompey.
I don't say to change the value of the capacitor but to short it (to jump), so to don't exist capacitor

Regards

I see!I read "sort" and I think that means to change it Also i made a mistake,I chaged C30 on my pcb,not C26 - C30 for audio frequency..

[Geo]

Hi,Geo,I already tried different caps.Yes the sound become more beautiful if you put 7-8nf instead of 10.But it seems to me like the depth goes less with changing sound to high frequency.

Hi pompey.
I don't say to change the value of the capacitor but to short it (to jump), so to don't exist capacitor

Regards

[Pompey]

Try to sort the C26. Sound becomes more good (not 555 version)

Hi,Geo,I already tried different caps.Yes the sound become more beautiful if you put 7-8nf instead of 10.But it seems to me like the depth goes less with changing sound to high frequency.