TESORO GOLDEN SABRE

[karlos x]

???

What are correct : 12,5 cm or 25 cm ???

[Friday]

radius: 12,5 cm

dia: 25 cm

[kuraja]

So... TL081 instead LM308 on TGSL?

[ivconic]

Could be used. I am oftenly using them, when can't obtain LM308.
In case of using TL081 you don't need 100pf external compensation.

[Esteban]

Still off-topic, huh ?

Did you see "El mariachi" (the movie) ?

Won Sundance Festival something 1991 or 1992... nice movie !

Kind regards,
Max

Max, I prefer this Sam Peckinpah's film, in wich are involved many mexicans too

[ivconic]

What was the movie where Michael Douglas showing Minelab Excalibur to his daughter (movie character)? Later they digining in the middle of supermarket!!
I have idea; let's open new thread where we gonna number all the movies with metal detectors involved...

[Esteban]

What was the movie where Michael Douglas showing Minelab Excalibur to his daughter (movie character)? Later they digining in the middle of supermarket!!
I have idea; let's open new thread where we gonna number all the movies with metal detectors involved...

Is a good idea.

[Max]

What was the movie where Michael Douglas showing Minelab Excalibur to his daughter (movie character)? Later they digining in the middle of supermarket!!
I have idea; let's open new thread where we gonna number all the movies with metal detectors involved...

Hi,
yes it's kinda of jolly thread then... there are a number of movies where MDs are shown... uhm... let me think at an old movie with Jack Lemmon... something around years 1987-1988 I think (I was at school at that time... and my school paid the ticket... otherwise I wasn't really happy to spend money to see that kind of movie... you know... I like much more the sci-fiction-splatters like Alien etc )

In that movie there's a guy on a beach with something (maybe a c-scope???) and a girl tell him about what he's searching for... e.g. used syringes...... the kind of humor that some people have when they see someone digging in the dirt...of a beach.

I'm not sure... but think the movie was something "that's life" or the like.

Ok... that's the first one I remember but I'm sure I will recall many more... where's that thread for movies ????

Kind regards,
Max

[Kahuna]

hi guy,

some problems and i need some help ...

first time i build a tgsl on selfmade pcb, at the first test i blow the lf353 and the lm 393 at rx stage by placing the 353 in opposite direction. both get very hot and i decided to replace both with new parts. and i decided to build the pcb from driscoll from page 113 with the same parts. so i removed all parts from pcb and placed them on new one. at this time i noticed that my dealer send me 2k2Ohm instead of 1MOhm. thats the prehistory

question: what parts could be damaged in case of taking 2k2 Resistors instead of 1M and whhat parts could be damaged if i turn the lf353 at 180°?

next ...

i finished the tgsl on the new pcb with new 353 and 393 on rx stage and real 1M. Coil is nulled. first test...
no tone ... i removed center tap from pcb ground and i get a tone.
second try ...
i switch it on and the machine starts to beep for many times. no change if i turn geb or sens pot, when i turn disc pot the beep stop (the machine is in all metall mode ?!?!?!). if i put some metall over coil i get an answer for detection and the beeps return. when i switch to disc mode i have no beeps and a good detection 1 euro at 25 cm. but the detection tone if the coin has a distance to coil from around 10cm is somtimes a double beep.
but... disc dont work ....
i can turn the pot in any dirction with no change. in every position i can detect aluminium, iron and 1 euro.

so ....

why it doesnt work with center tap on gnd
why i have an endless beeping in all metall mode
why id have no disc in discmode

some ideas ? i have no more ideas ... need some help pls

coil: wire 0.28 (dont know if it is with or without varnish)
DD dimensions like ivconics recipe
tx 104 , 19.7Ohm , 14,6KHz at tx stage
rx 110 center tapped, 27,7Ohm
nulled to 0,000V very easy

all parts are correct connected

THX





http://www.geotech1.com/forums/attachment.php?attachmentid=6621&d=1222438708

[Unregistered]

You are stupid, dont try to make md anymore!

[Kahuna]

yes i am ...

it can not give only intelligent and courageously people like you

[simonbaker]

hi guy,

some problems and i need some help ...

first time i build a tgsl on selfmade pcb, at the first test i blow the lf353 and the lm 393 at rx stage by placing the 353 in opposite direction. both get very hot and i decided to replace both with new parts. and i decided to build the pcb from driscoll from page 113 with the same parts. so i removed all parts from pcb and placed them on new one. at this time i noticed that my dealer send me 2k2Ohm instead of 1MOhm. thats the prehistory

question: what parts could be damaged in case of taking 2k2 Resistors instead of 1M and whhat parts could be damaged if i turn the lf353 at 180°?

next ...

i finished the tgsl on the new pcb with new 353 and 393 on rx stage and real 1M. Coil is nulled. first test...
no tone ... i removed center tap from pcb ground and i get a tone.
second try ...
i switch it on and the machine starts to beep for many times. no change if i turn geb or sens pot, when i turn disc pot the beep stop (the machine is in all metall mode ?!?!?!). if i put some metall over coil i get an answer for detection and the beeps return. when i switch to disc mode i have no beeps and a good detection 1 euro at 25 cm. but the detection tone if the coin has a distance to coil from around 10cm is somtimes a double beep.
but... disc dont work ....
i can turn the pot in any dirction with no change. in every position i can detect aluminium, iron and 1 euro.

so ....

why it doesnt work with center tap on gnd
why i have an endless beeping in all metall mode
why id have no disc in discmode

some ideas ? i have no more ideas ... need some help pls

coil: wire 0.28 (dont know if it is with or without varnish)
DD dimensions like ivconics recipe
tx 104 , 19.7Ohm , 14,6KHz at tx stage
rx 110 center tapped, 27,7Ohm
nulled to 0,000V very easy

all parts are correct connected

THX

Seems like you did pretty well so far. Do you have oscilloscope? Hard to troubleshoot without.

I think center tap on RX was experiment of Ivconics, but normal design doesn't have it.

Regards,

-SB

[Kahuna]

yes i have a digital one

today i checked coil with LCR-meter
TX: 5.8 mH
RX: 6.2 mH

should be in tollerance

replaced both bf245c cause i thought they could be damaged by false output of lm393.
centertap is removed

but same problems

can you give me some points for meassures with right datas so i can check this

would be nice

thx and regards

[simonbaker]

yes i have a digital one

today i checked coil with LCR-meter
TX: 5.8 mH
RX: 6.2 mH

should be in tollerance

replaced both bf245c cause i thought they could be damaged by false output of lm393.
centertap is removed

but same problems

can you give me some points for meassures with right datas so i can check this

would be nice

thx and regards

- One thing to start with -- try reversing the two RX leads to see if that changes the double-beep to a single beep.

- Check your supply voltages referenced to ground. V+ should be +8 volts. V- is typically -5 volts, plus or minus a volt. Check V- at the junction of D6 and C5, or any other place you see on the schematic.

To try to trouble shoot, we need to see your waveforms. Using a dual trace scope, capture the following pictures (with a digital camera for example) using two traces (called "top" and "bottom"):

1. TX waveform (pin 1 of J1) on top and RX waveform on bottom (pin 7 of U101a, output of RX LF353).

2. TX waveform (pin 1 of J1) on top and ground channel driver (pin 7 of u102b) on bottom.

3. TX waveform (pin 1 of J1) on top and all metal driver (pin 1 of J3) on bottom.

4. TX waveform (pin 1 of J1) on top and discrim driver (pin 3 of J3) on bottom.

It would be helpful to repeat #4 with the discrimination pot (R18 ) set in different positions, such as fully left, middle, and fully right.

It would also be helpful to repeat #2 and #3 with the ground balance pot (R22) in three different positions also.

I know that is a lot of pictures, but would be helpful for the experts here.

Best regards,

-SB

[Kahuna]

LOOOOOOOL

i solved the problem ... shame on me!!!!!

i had a led between positiv after switch and gnd ...
i had soldered it on next possible gnd near to led and thats in this case my geb pot.but ... i soldered it not to gnd input of pot i do it to the output pin
i saw it some minutes ago as the led goes lighter and darker by turning geb
i never take a look at it before ... lol

and that little thing do so much problems

no very quit
detection of 1 euro coin in 20 cm
disc work ... not fine but work
i hope it will be fine with better coil

after rechecking null with coil cable on it i have 23.4 mV

it could be better

so i'll make a better coil and i think it will be great


thx for hlp simonbaker

best regards

huna