chance pi build

[baum7154]

I look forward to hearing the progress on your Chance PI builds. Keep us posted!

Dan

[6666]

Chance PCB's and other bits have arrived , thanks Andy.

[kellogs]

Thanks heaps Dan it is great to have your help and in put will keep you posted on the build Regards kellogs

[baum7154]

Attached here are 2 pictures from Post 31 of this thread that show the PC board in the detector.

031.jpg 04.jpg

L1 is the hand wound toroid mentioned in the previous post above I believe it actually measured 280uh.

I should note that the PC board in these photos is one of the first releases from Silverdog (Version 0.8.4 firmware) and has had the necessary modifications to it to allow use of the Version 1.2.1 firmware. The current release from Silverdog has these mods incorporated in it and that makes the build easier

Dan

[baum7154]

hope we can start togehter a Chance 2015 Project
with latest updates from onboard components

last time i looked on Chance there was added a ferrite core choke on the board and some other parts, hope we can continue there
has anyone the latest part list?

---------------------------------------------------

You are correct my friend that there was a hand wound higher current 220uh toroidal choke that replaced L1. I salvaged a toroid and wound it with #26 awg enameled wire till it measured 220uh.

The original parts list Q2 KP505 was replaced with a 2SC945 bipolar transistor.

R3 was eliminated and a 3.3K resistor placed from the base of Q2 to the TO control input.

R9 was lowered from 1500 ohm to 820 ohm.

D9 1N4148 is eliminated.

A 1N4148 diode is placed across the R25 470K resistor.

A 1N4148 diode is placed across the SP1 and SP2 (cathode) points

You will not need the 390 damping resistor if you wind a much better coil in order to get to minimum sample delay (Guard Interval). The 8" 335uh fast spider coil detailed in COILS forum 'Chance PI Coil' thread requires about 1040 ohms damping.

These changes will get the detector running properly with the Version 1.2.1 firmware.

The 2 stage preamp modification is detailed in this thread and I will be happy to help anyone pursuing this mod.

The audio output isolation modification is also detailed in this thread and allows the use of a chassis grounded headphone jack.

Regards,

Dan

[bernte_one]

hope we can start togehter a Chance 2015 Project
with latest updates from onboard components

last time i looked on Chance there was added a ferrite core choke on the board and some other parts, hope we can continue there
has anyone the latest part list?

[bernte_one]

i will place a order too, but i have to check what components i will order too on your shop
which i hadnt here on stock, tactile Switches, caps,...

[6666]

Thanks Andy, have placed order.

[silverdog]

ok, the Pcb's are in - Atmegas arrive tomorrow so allow a couple of days for those to be ready
Both options can be found in the PCB section of my shop http://www.silverdog.co.uk/shop/inde...tegory&path=35

good luck

[silverdog]

Due to the time it takes to maintain enough parts, build the kits and dispatch them, I plan 2 offerings for CHANCE

1. CHANCE pcb and keypad pcb
2. CHANCE pcb and keypad pcb and programmed ATMEGA

quite a lot of the parts are also in my shop already

-----------------------------------
Andy will the keypad board be included with the main board as well?

Regards,

Dan

[baum7154]

Ok, i have had several inquiries about CHANCE recently - strange as nothing in almost 2 years , however I will get a batch of pcbs made - should be here within 10 days
Good luck all - not sure if i'll do a full kit yet

-----------------------------------
Andy will the keypad board be included with the main board as well?

Regards,

Dan

[bernte_one]

i´m interested too, thanks andy

[Alan Honolulu]

Hello Andy, great news, I would hope it can be a full kit if possible. Thanks again

[kellogs]

Hi Andy great news would love to build this kit up as i am starting to learn a lot more on this hobby would you please let us know when pcb are available thanks once again Kindest Regards kellogs

[6666]

Ok, i have had several inquiries about CHANCE recently - strange as nothing in almost 2 years , however I will get a batch of pcbs made - should be here within 10 days
Good luck all - not sure if i'll do a full kit yet

Thanks Andy