TESORO GOLDEN SABRE

[ivconic]

...

"Ivconic what do you think can I use CD3240 insted of LF353?
Will this afect performance?"
I checked this today. Havent seen any differences.It can be used
to replace LF353. (CA3240)
"Are you using metalbox for device and ground all to box?"
I am using plastic box.

"Ivconic what is this coin 1cm?The smalest I think is 1,5cm D!
please check again!If this is true than I am not even close to the
results that I have to achive!!!!
Can you preforme air test with 1 euro coin and post results please!"
Yes, you are right! Again i made stupid mistake by claiming something
without checking it first!? I am using that coin for several years, never
occured to me to measure it!? Somehow i conceived it is 1cm...?
Truth is; it is 2cm diammeter!? This really changes all your points of
looking at my results?
Yes, i agree,it would be almost impossible to detect such small coin(1cm)
with 22cm DD coil.
I have problem,issue with myself; things i am used to "see" my way are never
checked preciselly...Sorry!
Distances i already reported are TRUE. Do not have doubts.Only coin diammeter
was wrong. Actually it is 2cm. Dont know why i made that mistake?
This is international forum.I am also visiting many other simillar places on
the net. Have conntacts with many people, mostly i do talk in inches....must
be that i memorized this as one cm instead one inch...later all mixed up due
very tough rhythm i've been living lately. Very exausted, so few resting moments.
"Have we to split hairs here ?"
Yes Max, i agree with you. But this time TikTak is right, 1cm more does really
make difference! Although it is not easy for me to admit, i made huge mistake!
Erolunall, to tell you the truth; i never tested it on large items. I made it
for coinshooting, and coins&small items are only what interesting me.
But, if you wish i will test it these days on larger items and later post
results here.
"And NE566N what do you think is this make differance in audio.Ivconic tell that
he search for another solution!This mean that its not so good modification."
Yes it is worth of trying. Works better than without it.But i want some more,
that's why i am looking for another solution.
About LM566, well, problem is in signal level. It need voltage to produce certain
frequency - VCO. But at TGS output signal level is not compatible with what we
need to drive LM566. Some kind of converter is needed.
Realizing that, i had to think other way,so after a while i just put J107 to trigg.
it to -12v. It is sort of trick to provoke LM566 to start working. But sound is
still "monoharmonic",short and anoying. Benefits are louder sound and abillity to
adjust frequency of audio....
I am not satisfied at all with this. I imagined it other way. If we could use
variabile TGS output voltage to drive LM566 in manner to change audio frequency
respecting voltage changes at TGS output. That would be some progress! i experimented
some time, but without succes. Something is missing? I can not find proper way
to make level conversion there.
TGS output is in range -4.xx - +3.xx volts. Only positive part is starting LM566.
Another problem is small "resoultion" in those +3.xx volts. All changes in
frequency at LM566 are so fast i just cant hear differences.
I think 4046 would do the job better, only dont have clue how to use it!
Yes, i have all those schematics with 4046, but wired up in quite different manner,
not useable in this one...Need some time to think about it.


Still wandering! There is some 555 to check.....What do you think?

[Leto]

Originally Posted by tiktak
Hi,
Leto.
What kind of battery did you use?
And can you please tell me where to conect those ground points?
I wanna try your audio modification too.
The speaker is going in sane ground point as before,but where I should conect others?
What coil did you use with your TGS?

Max already answered your question.. but in other words: amplifier is powered directly from battery (Vs+,gnd-). I doubt you will found LM388 as it's not produced anymore - in this case you can use any small power audio amplifier...
About appropiate coils everything has been posted here by ApBerg, Ivconic, Max, Nelson and others..it's up to you to wind it and play with it.
I suggest you get a large stock of 0.25mm wire.

By-the-way: I found excelent replacement for LF353:
I tested LMC6082 and gained some stability and centimeter on coin..
LM8272, LMC6032, LMC662, LMP7702 should also work (National)

[Max]

Hi,
Max.
Can you tell me can I recharge this 10 pieces AAA 1,2v battery with ordenary AC/DC adapter set to 12v?Or I have to buy some special charger?
10 pieces conected in series and adapters + to battery + ;adapter - to battery-?
Thanks
p.s.I will go now to check one new source of wire.Hope can buy from them.

Hi,
you can buy one charger or use this simple regulator.

Current limit = 1.25/R
You need 1/10 of you battery capacity limit.
For 700mAh -> 70mA
R= 1.25/0.07 = 17.85ohm use 18ohm 1/2w
Then charge overnight for 12hours. Batteries must be discharged first... at least at 80% to avoid troubles.
Don't leave batteries connected to it without external supply.

Best regards,
Max

[tiktak]

Hi,

The probleme in nulling my coils is my multimeter!
Ivconic adviced me to conect Tx leads to TGS and RX directly to multimeter which is in 2V range,BUT my multimeter is with two AC ranges:
-200
-750
According to manifacture range 200V is with 100mV resolution!
I noticed when try nulling that its show 00.0- 00.1 and were thinking that this is under 1 mV ,but its not true!
And I will have to find relyable multimeter too.

[tiktak]

HI

Hi,
Max.
Can you tell me can I recharge this 10 pieces AAA 1,2v battery with ordenary AC/DC adapter set to 12v?Or I have to buy some special charger?
10 pieces conected in series and adapters + to battery + ;adapter - to battery-?
Thanks
p.s.I will go now to check one new source of wire.Hope can buy from them.

[Max]

Hi,
Max.
Yes you are right! they are labeled B10k not 10kB!!
It's look like you are well familiar with TESORO.
Can you please answer to my previous question about BATTERY?

Hi,
you can use a 12v battery lead-acid gel type 1.2Ah would be fine.
You could use also 10 AAA cells NiMh to get 12V say 700mAh or more, you'll have much less weight with NiMh, cause the lead-acid batteries are heavy due to lead inside + gel weight etc.
For the Leto's schematic you have to supply with 12V (B+) at Vs point, pin14; negative is your gnd on circuit, the same thing.

I'm familiar with homemade Tesoro's !
But if I have to buy a new detector they will be on top of my list for sure.

God bless Tesoro Electronics.

Kind regards,
Max

[tiktak]

Hi,

Hi,
Max.
Yes you are right! they are labeled B10k not 10kB!!
It's look like you are well familiar with TESORO.
Can you please answer to my previous question about BATTERY?

[Max]

Max,
Remember when we talk about potentiometers?Look at this picture!Its look like umax use 10kB,100kB this mean log?
But this maybe because umax is newer version?

Hi,
could be so... there is the MCU there.
But are you sure they are log pots ?

European and US pots are labelled e.g. 10KA for 10k linear pot
However, if you have a japanese maker same linear pot then it will be labelled B10K, if product follow their labeling standard.

Tesoro used asian made parts that time.

Best regards,
Max

[tiktak]

Max,
Remember when we talk about potentiometers?Look at this picture!Its look like umax use 10kB,100kB this mean log?
But this maybe because umax is newer version?

[Max]

Hello Max and others..

do not know about TBA820's but I'm very much satisfied with old lm388 - it works perfect. I connected it after C517 with 2k resistor it does just what's wanted: amplifies for 8ohm impendance speakers. Input resistor is really needed (or the amp. input is overloaded) maybe also lower gain transistor in place of C517 would be OK.

Higher consumption could be a problem for someone (10-15ma) but personally I do not use 9v batteries for long time now.

Hi Leto,
thanks for schematic. I've made with TBA820M and if connected like your (voltage splitter after c517) works really good, loud audio.

My problem was at first attempt cause I connected before c517... and there are voltages and impedance problems there.

TBA820M uses only 4mA when no sound... then consumption increase cause of sound to much more... it gives about 2W power on 8ohm.

The VID mod is really interesting, could be used to make a real useful multitone id.

I'll test it soon.

Thanks again,
Max

[tiktak]

Hi,

Hi,
Max.
You have advice me to try use 10 NiMh cells (1.2volts each) 700mA/h or more for TGS.But in shop they ask me which size?So which size is best?
And can I recharge them with AC/DC adapter?

[Max]

Ohhh..
I am in big trouble!
I spend all bloody day to wind coil, wind by wind, without any crossing of wires.I've used Chemelec inductance calculator and got results:
For 10 inch inside diameter coil (256mm) - O concetric coil
coil lenght: 0.2 inch (5mm)
wire diameter: 30 AWG or 0.27 mm with varnish
turns:117
inductance:7.1mH
I think that calculator is very, very good .
Everything looks fantastic, but no, no my friends! My freaky multimetar "told"
me the coil inductance isn't 7.1 mH (that should be RX coil), but 9.8 mH!

Let's say y is specific resistance (I haven't that bloody letter).

R=y x l/S then l=R x S/y

y for copper is 0.0172 ohm x mm2/m
resistance of my coil is 33 ohm

S=r2 x 3.14 ( I haven't bloody pi too) S=0.125 2 x3.14=0.0491 mm2
l=33 x 0.0491/0.0172 l=94 m

So, wire lenght of my coil is 94 m.

let's calculate on other way:
O=2 x r x 3.14 O=0.256 x 3.14=0.8 m

0.8 x 117 turns= 94 m - the same results.
So what, you can say, but now I am sure the number of turns is correct-117
And what now? Should I trust to my multimetar , it looks good, think it isn't from China, but who knows? Or should trust Chelmec?
Immediatly need help... help... help...
Yours Hush

Hi Hush,
sometimes happens you made a coil and then figure out the inductance is wrong from calculations, too many factors... even if you tight wire with tape you'll get an increase of inductance ! Not much but you can see it.
Sometimes is just LCR meter/multimeter that gives you strange numbers and you can't trust if not hi-quality device.

So what to do ?

1. follow ApBerg advices, he knows many things about GSabre, so he pointed you in the right direction

2. no need of too many calculations... make say 15% more turns than expected... then cut them away till reach your operative frequency (I got 14.35 KHz with GSabre , but my coil was developed for BandidoII, it's the same) Think that original freq. would be a bit over 14KHz, if remember well.

3. make then RX and a good null as explained before many times

4. shield as explained

5. test before sealing

6. seal and package the coil for real use

7. test on field (and cross fingers)

Best regards,
Max

PS: I have a device that use to test coils too... is a general purpose free oscillator (from few khz to 300Mhz I think) but cannot find schematic.
When use it I just put coil and a parallel cap, like in rx section... then measure osc frequency live !

It's a good thing cause it always oscillate !

If I'll find schematic I'll post it. It's easy to made.

[tiktak]

Hi

Hi,
Leto.
What kind of battery did you use?
And can you please tell me where to conect those ground points?
I wanna try your audio modification too.
The speaker is going in sane ground point as before,but where I should conect others?
What coil did you use with your TGS?

[ApBerg]

Hello Hush.

Think you want to make a open centre coil ?
Look at post no: 22. I made some opencentre coils, works well.
For the 25 cm coil the 117 turns are to many.

You can connect your coil to the transmitter part from the goldensabre and look for the freq that is given , use for golden 15 nF cap, freq must be somewere 14 kHz, if lower freq then reduce the 117 turns
Good luck

Ap

[Geo]

Hi Hush
Only if you have a standard induction . Another way is to give at a coil a AC voltage and to measure the voltage across the coil and the current who flow through the coil. Z=U/I and if the freq is high then the Z is very close to Xl. Xl=2*pi*L....... L= Xl/2*pi

(Z is the total resistance and Xl is the induction resistance). If the multimeter is OK then the L will be close to the multimeter reading.
Good luck