'KROT2-XM' (mole), new project Xmega32

[OCBSlimz]

@ Smity so I removed C18 (which was value 47 pf instead of 51pf, couldn't find 51pf) I added a jumper in its place and has reduced the mV to 156mV what else can I do ?

[smity]

Look carefully R7, R8, they should be 1% accuracy. Also pay attention to C14 (preferably tantalum). Without the coil, the balance should be around "0".
Take a picture of the good quality of its printed circuit board.

[OCBSlimz]

Hi Smitty Ive verified the resistors and capacitors and they are what you say. Capacitor is electrolytic Are there any more things i can try ???

[timekiller]

I think that mole is not critical to the components.
I have 3 completed , no need tantalum capacitor. 3-5 mv without coil is normal .All capactirs over 1 mkf are normal electrolytic in my mole - no bidirectional. Of course Tantalum and 0 mv is well.

[OCBSlimz]

I think that mole is not critical to the components.
I have 3 completed , no need tantalum capacitor. 3-5 mv without coil is normal .All capactirs over 1 mkf are normal electrolytic in my mole - no bidirectional. Of course Tantalum and 0 mv is well.

I'm on 200mv without coil. ... could i see some good HD photos of your boards ?? I'll get some up of mine tomorrow

[timekiller]

Of course, but my PCB is breadboard prototype .

[OCBSlimz]

Nice. Is that a 8091ar smd ?

[OCBSlimz]

[timekiller]

No 8091, MCP633 I think it is best choice.

[OCBSlimz]

I'm getting an RX reading of 56mv now. (Was 326mv) had to remove a capacitor (47pf) 1ny put a jumper in. Have cleaned the board and checked all solder joints.

I'm now at 56mv. Will an mcp633 affect this kind of mf reading on RX? ?

[timekiller]

In normal Mole 2 C18 - 22 pf , only in 3 frequency version C18 - 50 pf . Especially important C20 , C25 , C8 to be quality . R8 R7 is only volt divider , It is essential that there be a 1/2 of 3.3 v . R10 corect gain OA , It has a value of 600 om to 1.2 kom . For me 820 . The author recomend MCP633 and hi not use R11 .

[OCBSlimz]

Tried your method and my rx returns to 326mv. If I remove r11 it shoots to 4236mv ?!.

[timekiller]

This is not my method, it is 1:1 with the original scheme of mole2xm. My change in the scheme only the replacement of capacitors with polar electrolytic . Of course that these may be replaced.

[reptooyep]

Hi Everyone,
All is done now and i would like to know how to tune the whole detector.
I've finished the coil and plug it into my unit.
There are many tuning menus and i don't know how to start.
I don't want to fill my coil with epoxy before getting it working good.
i can see many tuning features :
TX frequency, coil balance, ferite, gain, etc ...and also the "mechanical coil balancing".
I have a 60MHZ oscilloscope.
Thanks

[smity]

I advise you to turn on Google translator and read this article. http://www.radiodom.org/publ/pervye_...t_alxv/1-1-0-2