CHANCE Pcb's Finally Here

[baum7154]

My software is version 0.8.4.

I am using coax but have way too much lead length (6")on the coil before it connects to the coax. Will shorten this ASAP. Also am considering using 300 ohm twin lead instead of coax.

Test outside today in the air were somewhat unimpressive. Unit did detect a roll of aluminum foil at about 24". Also detected my brass keys on a steel ring at about 8". Seemed to detect the vial of gold flakes at about 2-3" with only a very weak signal strength, but would not detect my gold ring.

I know it is said that the unit sensitivity is better when fully assembled so will pursue that end.

Regards,

Dan

[Tepco]

Small update on this. I put together my (old) chance, and programmed new software (8.04), and i have to admit it is much better now. More stability, better response, less prone to interference. I cannot claim anything about range (workbench, noisy conditions, high barrier setting etc) but some improvement is obvious. VDI also have more sense now. Looks quite good so far. Still useless as a beach machine (never intended to be), issue whit fast targets (jewelry) is still present, otherwise seems to be quite decent detector. And considering it is not especially fast maybe can accommodate larger coils as well. I have completed 12.5" coil and shaft for another detector, but i think will fit timing requirements for this one, will be interesting to see test results, i will put details here if it works.

[baum7154]

I took my unit outside yesterday and zeroed it with the coil laying on the grass as I still do not have it integrated into a package with a boom or electronics housing. The unit does detect my vial of gold flakes totaling the size/volume of a book match head. It also detects my gold wedding band very well from about 4-5". It appears to detect the gold flakes from various distances with the closest being about 3-4". There are steps of detection of the gold flakes with decreasingly smaller areas of sensitivity at about 7" and one at about 12". The 12 " area is really small I estimate it to be about 3/4" in diameter at 12". The unit also detected my iron fireplace poker at about 30".

I noticed the need for somewhat frequent resets using the ZERO button as the battery voltage was depleted below 10.8 volts. I have been running this unit on the same batteries for many hours now and I estimate the 8 AA batteries in the pack to have run the detector for at least 12 hours now.

Does anyone have any good ideas for a telescoping boom for the detector? I'm looking at the Seymour Superhandle II paint roller extenders. They are fiberglass construction with 2 twist locks for the boom extension. They come in 2'-to 4' and 4' to 8' lengths. I wonder if an aluminum boom on one of these will even work...any ideas?

I'm also wondering if the coil should be Faraday shielded at least on the top and was considering using the old black conductive plastic from old static protection bags. An ohm meter test on these gives resistance in the range of 50K ohms per inch.

Thanks

Dan

[baum7154]

Is 13.2 Volts OK?

I have a set of 11 1.2 volt nickel metal hydride batteries that I am considering using in my Chance PI. What problems do any of you see is using this higher voltage? It is a good voltage from the standpoint of charging directly from a car cigarette lighter. I think it would pretty hard to overcharge this pack in a car. Also I think the extra voltage may help performance a bit, but is it too much?

[baum7154]

Nimh batteries

Never mind, I just read several articles on charging Nimh batteries and a stack of 10 is best in the auto charge application.

[baum7154]

New CHANCE programming - Version 1

Silverdog et all,

Andy F has released new firmware, Version 1. This new version requires removal of D9 and a value change of R9 to 820 ohms. Also Q2 & R3 are now replaced with a 2SC945 and R3 becomes 3K3 (3000 ohms ?) on the base of Q2.

Apparently the new software has only 3 masks for FE discrimination and a chart of allegedly much improved metal discrimination is provided on the CHANCE site. The chart shows results with brass, copper, silver, nickel, zinc, aluminum, iron, & lead...but not gold.

Below is his quote from the MD4U Russian web site:

I finally present the new version of piercing - 1.0. To [skachat] it is possible from the page of instrument - http://fandy.vov.ru/Chance.htm . Program is completely rewritten, I hope, it came out better than it was. If something not then - it is reparable . For the correct work of the new version it is very desirable to conduct the apparatus modifications, indicated there, they in no way complex. END QUOTE

I was unable to download the new firmware but if you Silverdog can I would like to purchase another Atmel processor with it installed from you. Please let me know.

Regards,

Dan

[WM6]

Silverdog et all,

Andy F has released new firmware, Version 1.

I was unable to download the new firmware but if you Silverdog can I would like to purchase another Atmel processor with it installed from you. Please let me know.

Regards,

Dan

Thanks Dan.

Here you are newest firmware and some mods:

The new appointment of buttons:

* S1 "Barrier-/ Menu Down"
* S2 "Barrier + / Menu Up"
* S3 "Volume-/ Value-/ Value switch"
* S4 "Volume + / Value + / Value switch"
* S5 "Zero / OK (Enter)"
* S6 "Menu / Esc"


Graph comments (translated by Google):

1. 5 cents of the USSR (brass)
2. Soviet Union 2 kopeks (brass)
3. 15 cents 1915 (Ag, billon)
4. Russian 5 rubles (Cu)
5. 20 kopecks 1923 (Ag, billon)
6. 20 kopecks 1938 (nickel)
7. 1 kopek Nicholas I (Cu)
8. 2 RUB
9. 10 rubles 1993
10. USSR 1 ruble (nickel)
11. 5 cents of the USSR (brass)
12. 2 kopeks, Alexander I (Cu)
13. 10 pfenigov, III Reich (Zn)
14. 1 Russian ruble
15. 5 cents Catherine II (Cu)
16. 1 kopek Soviet Union (Brass)
17. 50 rubles in 1993
18. Roundels (Al) <----------------------- this can be near to gold caracteristic
19. German Button (Al)
20. Bullet Mignet (Pb)
21. 15 cents 1940 (nickel)
22. Nut (Fe)
23. Tin circle (Fe)
24. 50 kopeks Russia (Fe)
25. 10 kopeks Russia (Fe)
26. Roundels (Fe)
27. 5 cents of the Russian Federation (Fe)
28. 1 kopek Russia (fe)
29. Bolt (Fe)

[silverdog]

Ok I have the new firmware - All future Sales will be with the new Code
I will add just a Chip with the new code to the shop as well so existing users can upgrade if they wish

Silverdog

[silverdog]

I didn't realise how few CHANCE pcb's I had left after this weeks little burst of activity following the new firmware

I will need to order new boards very soon, could someone check the proposed pcb layout changes following the mods required for the new firmware

Any other suggestions for changes gratefully received - hole sizes etc.. ?

regards

Silverdog

[baum7154]

New Firmware Version 1.0.1

It appears that F Andy has another release, Version 1.0.1 FYI. According to the Babelfish translation it has to do with eliminating some of the 'Flicks'.

Also quickly looked at the board vs the mod schema and it appears the diagram for the speaker mod has the wrong polarity sign on the 1000 uf cap. Should be + not - where the cathode of the diode meets the cap. The diode can be easily mounted near the speaker connect points of the board.

Regards,

Dan

[okantex]

Hello ,
I could not see any development with this basket coil.
I used 0,75 wire , plate thickness is 3mm , rest is same with original coil.

I was hoping to see decrease at signal curve.
but result is different , it increased sataurated are , now decay starts much more later.
and could not see any sensitivity ,or how it reacts different for different metals.

is there anybody who got scope pictures of this basket coil to consider with mono coil?
regards
okantex

[WM6]

Hello ,
I could not see any development with this basket coil.
I used 0,75 wire , plate thickness is 3mm , rest is same with original coil.

okantex

Hi okantex

Which basket coil did you mean?

Can you post picture of it, here, to get an idea what you mean?

[okantex]

same as original , you can see details fromsilverdog's page
http://www.google.com.tr/imgres?imgu...L4Ss8gOO9uCcDg

[Tepco]

Can you post waveforms and picture of your coil? If you have any means, check coil inductivity, or very carefully visually check your coil. Trick is, it is very easy do mistakenly reverse winding direction at some point during assembly, without been noticed due to specific coil shape, and then coil wont work as expected.

[baum7154]

Firmware 1.0.1

Just installed new Atmel processor with latest 1.0.1 firmware from Silverdog and performed all mods suggested by FANDY. The unit goes thru its turn on routine and then just sits there buzzing with no signal strength indicated and does not change for any metal of any size at any distance from the coil. Does anyone have any different experience with this firmware version? I double checked all of my mods and they are correct.