GOLDSCAN 5 SCHEMATIC QUESTION

[Idefix]

GS5 AUDIO V1.zip

Hi,
just a help : may be better to add a revision number to files, even on the zip.
Like V1.01 V1.02 an so on. Filev1.01.zip..
If not , once downloaded , there is only the date inside to identify..

[dbanner]

Yes, good idea, but when trying to unzip, will the file extension be recognized(*V.0.1.zip)? I will do this from now on.

[Geo]

We must assume then, that TDI has three stages in the preamplifier...
Jose

Yes, but i don't have the values of resistances to determine the gain....

[dbanner]

In pdf

[Idefix]

At TDI the second preamplifier is a NE5532, not a AD8055 as at GS5.

Hi,
Would you post a picture of these part of the board ?
With a 5532 , there will only have 2 resistors by OPamp, and there will be close to circuit.

[Qiaozhi]

It would probably be best if you guys nominate one person to maintain the master files, and others can make suggestions by posting modified schematics and /or PCB layout. You cannot possibly all work on the database at the same time. Even with some form of revision control, only one person can check out the design at any time. Otherwise it will become a free-for-all, and anyone working on this will become frustrated.

On a positive note ... it's good to see a number of Geotech members working together to solve a problem.

[Altra]

I left out this section, and what about this resistor? Is this right on schematic?

Remember this was a proto type test unit. Two 100k's in parallel to make 50k later they have used a 47k ? The amp you left out was not used on the production model.

[dbanner]

Thanks. I try with 47K, this is logical.

[Altra]

At TDI the second preamplifier is a NE5532, not a AD8055 as at GS5.

Here is a TDI picture with a NE5532. Maybe a cheap replacement for the NE5534 and AD8055?

[dbanner]

I see a multiplexer chip(HEF4053BT). This is more advanced circuitry. since the TDI is now out of production, its resale value is bound to go up? As for front end, cant make out some numbers, picture resolution not so good. i also see a 16 lead LT1114S(pin 8 and 9 N.C.)

[Koala]

Not been following this thread so apologize if this has already been posted.

seems to quite a few photos and info here

http://australianelectronicgoldprosp...can-detectors/

[Altra]

I see a multiplexer chip(HEF4053BT). This is more advanced circuitry. since the TDI is now out of production, its resale value is bound to go up? As for front end, cant make out some numbers, picture resolution not so good. i also see a 16 lead LT1114S(pin 8 and 9 N.C.)

From what I understand they only discontinued the "Pro" they still produce the "SL". The pro runs on 14.4v and the sl 12v. In the photo all the timing is done with a micro. They also added a noise blanking circuit on the gb channel which may be some of the differences seen in the parts. Too bad Carl and Eric can't chime in on the details. Looking at Jose's schematic, it would make a great project. I would just add the Hi/lo tone switch to the audio and it's complete.

For more details google "TDI Reg Sniff" he posted a lot of information.

@Koala - Good info.

[6666]

What ever happened to Reg ?, I miss his informative posts across the various forums.

[6666]

Hi,
just a help : may be better to add a revision number to files, even on the zip.
Like V1.01 V1.02 an so on. Filev1.01.zip..
If not , once downloaded , there is only the date inside to identify..

Good idea about the file name, that will help keep us up to date.

[dbanner]

Question for gurus: can a spice model be done for just the ad654, and how about using a regular 555 in its place? as i dont have ad654, i cant experiment.