GOLDSCAN 5 SCHEMATIC QUESTION

[Orbit]

Here is a preamp which would feed single cap integrators from one of my builds. Change the AD8055 to 1/2 NE5532 and it may be what Geo's TDI preamp configuration looks like? Some good photos would tell.

Also i think yes! !

[Altra]

Here is a preamp which would feed single cap integrators from one of my builds. Change the AD8055 to 1/2 NE5532 and it may be what Geo's TDI preamp configuration looks like? Some good photos would tell.

[Idefix]

Hi,
As I understand, there were the TDI, and the Goldscan 5. After, merging the knowhow from those two, the TDI Pro was born, with all the improvments , and sometimes some compromise.
So I think the TDI pro contains the last evolutions to be followed.

[Orbit]

I think next ..The first operational amplifier ne 5534 has a very small gain double operational amplifier ne 5532 all metal channel there are, say, reinforcements from 500 x , while golden channel other half ne 5532 we amplify 1000 x and then, on the channel aplly filter time we get more gain with less noise ! That's my idea noise reduction !The amplification of operational amplifiers is arbitrary !

[Idefix]

Idefix

Which photo? My board has a NE5534 and a AD8055. The second photo was not my board it was from this forum which showed a NE5532 and Geo clarified that a NE5534 was hidden under the wires

Altra, the photo in post #222.
The marks on the first preamp IC are not very clear.

[Altra]

No, I think they may have changed to single capacitor integrators. See the SD2000 schematic. Differential integrators need matched caps and resistors, so it's easier to mass produce a detector using single cap integrators.

[dbanner]

Idefix

Which photo? My board has a NE5534 and a AD8055. The second photo was not my board it was from this forum which showed a NE5532 and Geo clarified that a NE5534 was hidden under the wires

Does this imply an additional preamp stage?

[Altra]

Idefix

Which photo? My board has a NE5534 and a AD8055. The second photo was not my board it was from this forum which showed a NE5532 and Geo clarified that a NE5534 was hidden under the wires

[6666]

There is more version ,I'm interested in how much noise there is ,on all metals and how much profit the GEB ??Gabi and Jose can see a video clip ?? If Altra can put the video its TDI proto ?!

I noticed that the differential integrator in the GS 4 application generate noise as well as the synchronization cd 4538 ! I think that's the main reason among other things applied by mcu as well as 4053 by TDI SL !


https://www.youtube.com/watch?v=dV-3yKez6YY My version 1.0 ]http://tinypic.com/r/2dbm06f/9[ATTACH]41096[/ATTACH]

Is it possible to get a higher resolution picture of your circuit please, when I zoom in to read circuit values it pixilates too much, thanks.

[Idefix]

Hi,
To Geo : the photo is with too low definition to see the value of smd resistor.
So if you can make a more close picture to the board, it will be better.

Hi Geo, Have you had oportunity to take some more pictures?

[Idefix]

Hi Altra,

I sent you a PM about your TDI . Have you have a look at what I said ?

[Geo]

The mod by Reg works only at GEB mode and it increase the gain about 20%
At GEB=Off it works the same as before mod.

[Orbit]

Thank you Altra greetings to Jose ! I tried the filter to reduce noise and it is decreasing ,Noise is reduced totally ,but it also reduces profit with the included Geb !Noise is reduced if we reduce profits in the front !This video is not convincing me I have less noise on my design or similar to the video .

[Altra]

Orbit my unit sounds just like the unit in this video. When my unit is ground balanced it chatters more and mid range target like brass have very weak responses.

https://www.youtube.com/watch?v=ghxASe3pkqQ

Reg Sniff was doing mods on GS5's and early TDI's to reduce noise in the GB channel. It would be nice to figure out what he was doing.

Demonstration of noise reduction

https://www.youtube.com/watch?v=s0DXQFCF8F0

Reg talks a little about the noise reduction here.

http://australianelectronicgoldprospectingforum.com/whites-tdi-and-eric-foster-goldscan-detectors/manufacturer-features-unpopulated-on-latest-gen-tdi-pcb/

[Jose]

Thanks Orbita, for publishing the scheme.
There is little noise with a single channel, the noise increases when connecting the GB channel.
The high gain of the GB channel seems to be the main cause of the noise.
I do not know how to solve that problem, I was thinking of some type of LP filter as the QED uses, after the integrator, but I have not tested it.
Later I will make a video.
Jose