SD2000 Front end

[Qiaozhi]

Hmmmmm what can I say ,,
xie xie , trima kasi

mei guanxi.

[Aziz]

Here is the operation of the pre-amp of SD2000 described in the following application note:

http://www.national.com/an/LB/LB-52.pdf

Aziz

[1843]

Hi gef,

I completed the my SD2000.... It works very unstable because of the breadboard and internal noises... it detects a gold ring at 12cm...
This machine must be made on pcb to get the best performance.

Regards,
1843

[gef12]

Hmmmmm what can I say ,,
xie xie , trima kasi

[Qiaozhi]

The 3 Pees :
Patients, Perseverance and Persistence, will get what you desire.
73's Regards Gef

I think you mean:
The 3 Ps:
Patience, Perseverance and Persistence, will get what you desire.

Unless, of course, you're a doctor ... then you might need the patients!

[1843]

Hi gef,

I use breadboard... I don't use any 5534 because of their low slew rate, AD8055 is fast enough that Q11 and Q12 can be removed.

Regards
1843

[gef12]

Hi
I would be keen to build one also.. what type of platform are you building on , breadboard or PCB. Also maybe a AD797 vice 5534 ??
8055 would be good too. Would be interesting project to build
cheers

[1843]

Hi Max,

OK! I am building an SD2000... but with a lot difference! I want to use an AD8055 instead of the above stage...

Thanks,
1843

[Max]

Hi all,

How much is the total gain of the following stage of SD2000?

[ATTACH]5610[/ATTACH]

Kind regards,
1843

Hi,
do you need it exact ???
it's high...consider that ne5534 has 6000 as typ gain at 10Khz. The supermatch pair is employed as an extern differential input stage, and will amplify too the signal... so you can expect something 6000-8000, if input signal is around 10Khz, depending on op amp selection too.

Kind regards,
Max

[1843]

Hi all,

How much is the total gain of the following stage of SD2000?



Kind regards,
1843