IGSL

[satdaveuk]

Pleased your back Ivconic
Nice design , I will make that later in the year
All the best
Dave

[Jerry]

This looks like another good project. Thank you for posting it and welcome back!

Jerry

[habitbraker]

Hello!

While assembling pcb i spoted error - R29,R47 (100K) are missing. On PCB its where upper LF347 are.

I just broke those two traces and soldered reisistors below pcb...

Havent finished yet -I will post other errors if I find them and results as well

[ivconic]

Hello!

While assembling pcb i spoted error - R29,R47 (100K) are missing. On PCB its where upper LF347 are.

I just broke those two traces and soldered reisistors below pcb...

Havent finished yet -I will post other errors if I find them and results as well

Damn! You are right!

I also spotted another mistake: D15 and D16 are connected wrong. Don't mind - just omit those. Those are not relevant much.
Regards!

[habitbraker]

Thanks! Not so hard to corroct also.

Im wondering - what are d15,d16 purpose anyway?

[habitbraker]

Another question - it looks to me that both, fe and non-fe, blocks are completely same. Then whats making that diffrence that one rejects iron and other rejects non-iron metals?
Or am I missing something?

sorry ! I spotted that fe block ANDer have changed polarities

[ivconic]

[ivconic]

Thanks! Not so hard to corroct also.

Im wondering - what are d15,d16 purpose anyway?

Additional "rectifying" & stabilizing over transients. Not really important... those two. Differences can be observed barely on scope. Small benefit, so you can omit those if you want.

[turtlebowl]

So nice to see you back here Ivconic!
Is there an expanded Iron range on this project?? That would be sweet, especially with the idea behind the way this machine is designed to operate.
I've often wondered what it would take to alter and expand/lower the iron range on a Tesoro?? I saw once that SB had begun to experiment with that but dropped the attempt. Is it not practical on the Tesoro circuit?? or just a matter of no interest??
Or does this circuit have that ability??
Thank's again Ivconic!

[ivconic]

So nice to see you back here Ivconic!
Is there an expanded Iron range on this project?? That would be sweet, especially with the idea behind the way this machine is designed to operate.
I've often wondered what it would take to alter and expand/lower the iron range on a Tesoro?? I saw once that SB had begun to experiment with that but dropped the attempt. Is it not practical on the Tesoro circuit?? or just a matter of no interest??
Or does this circuit have that ability??
Thank's again Ivconic!

Actually yes it has. "Fe block" is having exactly that role. Maybe is not visible by skim look on schematic - but in reality it is the case.

[turtlebowl]

Another thing you could explain. To help understand the working of your new project.
This time you have chosen to use different IC line up. Is there a reason for this? Or simply what is more easy available to you in your country? If there is a reason please explain how this new chips advance the design.
As stated in my last post....what is interesting to me is an extended iron range and I just want to know if your choice of IC's have anything to do with that.
The more I look at the circuit the more I want to make. Just want to know as much as I can before I start to order parts.

[ivconic]

I have excellent experiences with LF347. Used it many times when making SMW. About LM833... no special reason, just want to try it. LM833 already met on Minelab FT16000. It is good opamp, worth of trying. Use of quad opamps will preserve much space on pcb, that's why i used them - to draw smaller pcb.

RX input opamp is important choice. In the past, making a lot of TGSL's; i experimented with various opamps. Noticed significant differences in phase shift at some opamps. At some it can be corrected by changing some caps around it - and at some was difficult to achieve that. Aside LF353 i also had descent results with TL082 at that stage. At the time i hadn't LM833. Recently i got several pieces and decided to try it here. At second block i missed one opamp and that's why i put TL081 although LF351 can be used there too, and presumably many others too. So i didn't focused on extended iron range at the time, but it turned just like that later, when i joined two TGSL's to check this idea!?

Two GEB's here are also very important! Without second GEB there is no linearity and matching in GEB/other channel relations. With one GEB, when (for example) GEB adjusted to reject ferrite at one block - it is still accepted at another block!? That's why second GEB is included. Now both GEB's are separately adjusted to achieve same level of rejecting at both block's. GEB directly affects phase and therefore is very useful in defining "range" at specific block.

[turtlebowl]

Thanks for confirming. I have same experience with another machine when I try different components but that machine was not a Tesoro.
I have never used some of the chips you have chosen. It will be nice to have more new choices to play with, I will look today for them. Last week a man gave me a sleeve of LT1007 and I want to try them also. I heard they were a good chip sub for the 308 and others.
Thank you also Habit Breaker for your reports on your progress and findings on the PCB.
You'll have yours up and running long before I and I am envious. This is a different design and will be fun to get to know it and what it will do.
TB

[habitbraker]

Hello again!

Looks like there are two unmarked diodes on PCB connecting q5/q6 and q7/q8 collectors to Q9 base. Not shown on shematic.
IMHO it would work with and without(short) them. Are those any improtant?

Now I am short of parts so it will take a while to resume job. Will post anything new!

[ivconic]

Hello again!

Looks like there are two unmarked diodes on PCB connecting q5/q6 and q7/q8 collectors to Q9 base. Not shown on shematic.
IMHO it would work with and without(short) them. Are those any improtant?

Now I am short of parts so it will take a while to resume job. Will post anything new!

Short them for now...