IGSL

[ivconic]

I may need to tweak ground balance - on the fly on hols tomorrow.


As you look at the pcb osc is top left power reg is top right

which trimmers do this?

Please tell me location or sketch - No numbers pls

I cant read the silkscreen - as parts obscure them.

Steve

...

[silverdog]

IGSL

sorry, missed this one earlier

Ground Balance trimmers are Tr1, Tr2, left hand side above LF351

[golfnut]

Any takers with my last post - Im going in a couple of hours...

[golfnut]

I may need to tweak ground balance - on the fly on hols tomorrow.


As you look at the pcb osc is top left power reg is top right

which trimmers do this?

Please tell me location or sketch - No numbers pls

I cant read the silkscreen - as parts obscure them.

Steve

[der_fisherman]

Hi bernte_one,

many thanks for your post, most interesting and informative, it will help me to finish my MD over the next few weeks.

regards

Andy

[bernte_one]

for andy

yes unshielded coil i use it every time for first testing only

for all
at the moment i use ten eneloop 1,2v batterie pack it is placed near elbow stem perfect balanced for more hungry units like pi´s i use three or four 18650 in serie (12 or 16V)

more threads

power

http://www.geotech1.com/forums/showthread.php?t=17810

stem

http://www.geotech1.com/forums/showthread.php?t=17958

regards

[Amalio]

I think not.
Anyway; you can change those if you like and see if there are differences.

I'm changing capacitors and resistors in the discrimination of my modules IGLS musketeer, and see results first.

maybe later try 5K1 resistors

greetings

[ivconic]

Hello Ivconic

talking about changes, R7 and R8 5K1 more?

worth changing?

greetings

I think not.
Anyway; you can change those if you like and see if there are differences.

[Jerry]

Jerry, Im with you on the battery mass.

On my IGSL, I have a remote battery and a miniture power socket on the front panel.


The 3 Lithium ions I robbed from a duff laptop battery from work,.

If you cut the pack there will be a dying cell - easily id when you separate all of the cells out. Often 6 arranged 2 in parallel - three times.

Anyway, do three in series to get 12v 1800mAH

To charge I got a £5 charger/balancer from Giant Cod.

You also need a plug and flying lead to charge - it will have 4 wires - one + , - , and the cell junctions.

I use pvc heatshrink to get a 'Pack', plus 2 foot of flying lead - sorted.
The charge lead pokes out of the heatshrink for charging.

I will arrange a pic if any takers
Steve

Good idea! I just happen to have several of old laptops with dead batteries.

On TGSL is use two 9 volt in series however for IGSL I think a different approach is needed.

Jerry

[golfnut]

Jerry, Im with you on the battery mass.

On my IGSL, I have a remote battery and a miniture power socket on the front panel.


The 3 Lithium ions I robbed from a duff laptop battery from work,.

If you cut the pack there will be a dying cell - easily id when you separate all of the cells out. Often 6 arranged 2 in parallel - three times.

Anyway, do three in series to get 12v 1800mAH

To charge I got a £5 charger/balancer from Giant Cod.

You also need a plug and flying lead to charge - it will have 4 wires - one + , - , and the cell junctions.

I use pvc heatshrink to get a 'Pack', plus 2 foot of flying lead - sorted.
The charge lead pokes out of the heatshrink for charging.

I will arrange a pic if any takers
Steve

[Amalio]

Bernte that's good for now.
Coil must be more precise balanced.
Those small chatters that appears from time to time are caused by increased gain at channels.
For now you just do make small changes and return values as noted on sketch bellow.
Instead 1M5 put 470k and instead 10nF put 22nF, on all places noted on sketch.
That's how you will void those chatters and instability.
I wanted to experiment with higher gain than and later realized that it was bad idea.
So, when you return values like those are at TGSL, you will not have chatters and instability and therefore will be able to balance coil more easily.
Cheers!

Hello Ivconic

talking about changes, R7 and R8 5K1 more?

worth changing?

greetings

[der_fisherman]

I think audio part should hold 18v there. Give it a try with bench supply before you buy batteries.

I got given the batteries and the charger for nothing!
Can't get cheaper than that!!!
Regards
Andy

[ivconic]

Hi Ivconic and SilverDog,

firstly many thanks Ivconic for the recent recommendations to reduce gain slightly, I think that will help my machine quite a bit, though its going to take a week or so to get hold of the parts needed as I don't have them to hand.....

I have another question for you and SD, I would be grateful for both of your opinions:-

I have looked at the schematic and it appears that the input 12 volts from the battery is only used (unregulated) for driving the loudspeaker, otherwise it just supplies the 8 volt regulator. Am I correct?

Now would the loudspeaker take 18 volts at that point (SilverDog, what are the specs of the little loudspeaker you supplied in the kit?) as I am looking at two good 18v rechargeable battery packs and of course the charger that I have left over from a battery drill with a burnt out motor that I was given, almost new......

I could put in a bigger value resistor to drop the voltage instead of the 330 ohm (R69), but if I can get the loudspeaker louder instead, that would be great!!

I am also thinking of cutting off the whole handle of the drill and eventually attaching it to my MD (high up for a better balance) so that the batteries can be plugged in from outside of the machine once charged......might look quite good as well!!

Maybe such rechargeable drills, that can be bought very cheaply, could be a good source of batteries, charger and socket.......even when bought new.....I saw one today for around $20 (€15). Individual batteries (2 sets), battery holder and charger etc., would cost more I feel.....of course a broken drill is even cheaper....

Thanks in advance to you both for your thoughts and ideas.

Regards

Andy

I think audio part should hold 18v there. Give it a try with bench supply before you buy batteries.

[ivconic]

in my lunch break i bought the parts for replacement
seems to make sens
with my diy 28cm dd coil my igsl musketeer reacts to my body when moving around
and i think thats not only caused from my missing shield

on my tgsl i havn´t this problem at first tests with unshielded coils

it can be a result of the gain

better to set the gain down as to have much of false signal on field

You should apply shield on each coil.
You simply can not expect coil to work stable without it!?
Yet, even without shield it shouldn't react to you moving around it.
I think there is also something else bad that cause such behavior.

[ivconic]

Just curious, I am currently working on 2 boards of the IGSL Musketeer version. Have an 8 and 10" Musketeer coil to use with it.

Are you suggesting to change out those parts for less gain to stabilize the detector from chattering too much? Or am I ok to leave them as they were orig. marked. Or do you suggest I build one board with the high gain parts and one with the lower gain parts?

R31, 45, 50, 64 currently 1m5 change to 470K
C16, 24, 29, 37 currently 10n change to 22n

Yes i suggest 1M5 to be replaced with 470k and 10nF with 22nF as it is on TGSL.
Actually there is no need for higher gain there, benefits nothing.
But can cause internal chatters and instability.
It was just my experiment than.