IGSL

[Davor]

Yes, this is a Grozdev design. His Tx is balanced as well, also using a centre tap (that's the way to obtain lots of power, and simultaneously reduce Rx to Tx coupling).

[liekwang]

?Davor I revamp the shield of al foil and a gold ring can detect on 19cm's voice is very clear and it detects also a piece of red brick with a distance of 10 cm is detected for me was okay for now but I am not satisfied with the current depth

[Davor]

Detecting a brick says you have bad adjustment of ground balance, so one step at the time...

[liekwang]

?If it can remove bricks detection is very poor what if GB rotating clockwise direction opposite to the detection of the bricks are gone but the poor against metal

[Davor]

Original IGSL schematic is a bit confusing with independent tuning of GB. That's why I joined GB of both channels and made it tunable from the front panel.

[liekwang]

?Sensitive can be up to 30 cm deep but also sensitive to the red brick if GB I turn left onto sensitive being poor but not sensitive to red brick GB I have one on the Front Panel so I've joined your suggestions

[Davor]

Well, I'm not certain you are tuning your GB properly. Finding a proper GB is supposed to zero response to brick only, not all spectrum. Perhaps you'd do better if you wrap things up and go for some real hunting. Eventually you'll learn how to tune GB.

[Davor]

Anyway, I played a bit with AB->C class Tx of IGSL and it turns out to be a perfect candidate for this, as there is a driver transistor that is easy to manipulate. I also found a simple network that can double the amplitude on an existing coil (6dB gain) and make it quasi balanced in the same go. More on these this evening or some other day.

[labtec1]

Hello everyone
The power IGSL use LION battery that I got off with a laptop (3 cells connected in series), but I do not have a charger for them
how to make battery
given to any of you has a scheme for making
Filling ordinary transformer would kill the battery charger
thank you

[Davor]

You need a balanced charger for these, e.g. every battery is charged individually, and therefore the laptop batteries have so many contacts.

[golfnut]

You need a balance charger as davor says,

Li - cells cannot be charged above 4.2v per cell. You cant simply charge then in series like nicads or NiHh

There are cheap china chargers with multiple cell connections.


These are inexpensive and effective ...

http://www.giantshark.co.uk/product/...alance-charger

I use this technique and have used cells from laptop packs - last for ages between charges too.

S

[golfnut]

this is one I made up one time I think they were 1800mH its about 12v... best of all free. See your IT guy for an old laptop pack, bust it open- with care. Dont short out as will get exciting. Measure the cells one is normally dead. The others will be ok.
S

[Davor]

Or you can get one of these: https://dx.com/p/portable-6800mah-em...eu-plug-135958 just as I'm about to do myself.

[didier]

Hello,
I want to share some information about the coil shield with you. I have opened a Wima, 1 mikrofarad 250 V bipolar capacitor . I opened it with a saw just along the circumference until the plastic housing material was removed. I opened the capacitor carefully and found the capictor foil partly damaged. I removed the damaged, cut part and had about 2 m of undamaged foil available.
The aluminium is metallized on a very thin plastic foil, and is about 2cm in width. When the foil is uncoiled you can observe that it consists of 2 layers (the 2 electrodes of the capacitor). It is possible, to separate those 2 layers again just by pulling, and in the end you have 4 m of foil or more, which is sufficient to shield several coils. When you measure the Al foil, you can see that one side is not conductive (the plastic foil side) and the other side is conductive. I measured a resistance of 50 Ohm for 1 m of foil. The advantage to normal Al foil is that it is much thinner (maybe less intensity loss ?) and that it is much easier to apply this foil compared to Al household foil. It is more like a very thin adhesive tape (without glue). I shielded my coil this way and it was easy to do.


didier

[liekwang]

Hi davor my cannot yet still for GB the Earth if the real test in the field are still sensitive to soil test in the air very well and can resist the red brick and stone containing the mineral iron can be denied though not as full as the real test however rejected her, the situation is very bad there has always been a false signal this problem I haven't been able to resolve a false signal to the real field test