Sovereign coil amp

[samd12]

I am looking for the schematic for the AD797 coil amplifier in the sovereign. One that has all the components identified, I can only seem to find the LT1028.
It is my understanding that the AD797 is an updated version and a bit better?
Thanks

[Geo]

I constructed the "Sovereign" amplifier with both ICs. Practical no difference.

[plumabob]

Here is the AD797 circuit

[samd12]

Awesome, thanks for the replies!!!

[Ism]

Can someone tell me the voltage created by the transmit wires (1 and 2) for powering the AD797?

[DavidB]

I can tell the preamp is a drawing I posted about 8 yrs ago with the LT1028. Someone just changed the values.
I guess it depends on which Sovereign. The original model used a 12v battery pack. Since it is a non resonant type coil more like a pulse transformer with rectangular waveforms applied, the total voltage across the transmit coil is 24V. The H bridge FETS switch 12V across the coil on one half of the cycle then 12V in the opposite polarity on the other half of the cycle.
There are a lot of new choices out there when it comes to low noise opamps for the preamp.

[FOMA]

Another option. Himself copied. Coil BBS800.

[kt315]

Mike offered a correction, to visit http://www.geotech1.com/forums/showt...ight=Sovereign

[FOMA]

The legs grow from here.
http://www.md4u.ru/forum/viewtopic.p...2301&start=175

[DavidB]

A picture of the LT1028 BD. I guess they changed over to a 50 cent amp with a discrete low noise front end on the latter version. Probably works just as good or better. I am experimenting with a OPA1611.

[kt315]

David, please do your photos on sunny day time. wait this time and do. I ask all people NOT DO SAME VERY BLUR PHOTOS LIKE THIS ONE DAVID SHARED.

[kt315]

...

[plumabob]

DavidB,

I have already used the OPA1611 as a replacement in the AD797 circuit above with great success. Use the AD797 values not the LT1028. Give it a try.

Bob

[DavidB]

Those 2 are pictures of my coil that I posted some time ago. You can tell by the shape of the glue blob and those are my data sheets. The last one I posted was from a cheap microscope camera and I was holding it. I had forgotten all about the original post. I also posted some partial Sovereign schematics back then.
Thanks for the gain setting tip on the OPA1611 MR. Plumabob. I also have a LME49990 to try.