2 boxxxx :)

[chemelec]

This Preliminary Article is now on my website:
his Includes the Reciever and transmitter schematics as well as the Reciever PCB and a Picture of it.

http://www3.telus.net/chemelec/Projects/Projects.htm

I believe the schematics are drawn correct.
I will be posting the PCB for the transmitter in a few days.

Other info will follow later.

[chemelec]

Both Schematics and PCB's have now been Tested and work properly.
They are now posted on my site.

However it may be awhile before I get a complete unit put together. Too Many other things going on.

In reality I have no use for this detector, but I enjoyed the chalange to recreate it so it can be built with parts that are available now.

Who Knows, Tomorrow they may Obsolete all transisors. This field is changing Far too fast.

[Geo]

Hi Gary. Did you made field test? If yes which is the sensitivity?

Geo

[okantex]

If this T/R locators really get the reflected signal from the metal laying underground, can not we make a discrimination unit.if unit gets reflected signal , recieved frequency must change according to metal type.
Okan

[chemelec]

Sorry No. Until I actually build up a completed unit with boxes, coils and everything, I can't do that.
I do Plan to Complete it, Mostly just out of Curosity, than probably scrap it.
Most Project Designs I do are just to give for free to others to help them out.

However my reciever circuit has the same gain (Actually a Bit Higher) as the origional CA3035 IC. And although I designed the Transmitter a bit different, its RF Signal is also as good as the Origional.

Therefore: I would conclude it should perform as well or better than the origional design.

In the PDF article I have on the Origional design by Charles Rakes, He claims the reciever can detect the transmitter at 25 Feet.
But it did Not give any figures on Actual detection of any objects.

Take care.........Gary
************************************************** ********

Hi Gary. Did you made field test? If yes which is the sensitivity?

Geo

[Geo]

In the PDF article I have on the Origional design by Charles Rakes, He claims the reciever can detect the transmitter at 25 Feet.
But it did Not give any figures on Actual detection of any objects.

Take care.........Gary
************************************************** ********

Theoretically this is the double of the max depth for large objects.(25 Feets / 2).

Have a good day

Geo

[chemelec]

My First Prototype of this detector is now all together. It Works fairly good!

I have another job I need to do for a few days before I can work on it again.
Than further testing and hopefully more Improvements.

There is a Photo of it on my website.

[Geo]

Hi Gary.

Good work. Congratulations. When you will work again with the project try to put the horizontal coil about 3..4 cm down to be horizontal with the center of the vertical coil. Maybe so to have null with better sens.
Have a good day

[Roberto]

tr locator ?????

Hi friends! I am mounting locator detector "T R" (two boxes) already I finished the circuit and I am with a doubt, which the size of the bobbins? which wire I must use? e which in the distance between them? how many returns approximately?:confused: :confused: :confused:




Olá amigos!! Estou montando o detector "T R locator" (duas caixas ) já terminei o circuito e estou com uma dúvida, qual o tamanho das bobinas?? qual fio devo usar?? e qual a distância entre elas?? quantas voltas aproximadamente? :confused: :confused: :confused:

[ivconic]

2kHz 2 box servizinfo

I just made that and it is acting funny?
It is acting like detecting somthing but...
here is the pic with my notes...If any body can explain...
Two Box from Charles D.Rakes works much,much better...even very usefull..
regards!

[chemelec]

I just made that and it is acting funny?
It is acting like detecting somthing but...
here is the pic with my notes...If any body can explain...
Two Box from Charles D.Rakes works much,much better...even very usefull..
regards!

A few answers:

S1.1 and S1.2 is a single DPDT Switch.
500 uF is good.

In the supply, Personally I would use a 741.

[Geo]

Hi Ivconic.
you may build it without switch only one diode one resistor and one capacitor. I believe that 47uF is enough to demodulate the signal. Now for LM324 you can use any other op-amplifier.
If you finished it give us some test results

[Geo]

Hi friends! I am mounting locator detector "T R" (two boxes) already I finished the circuit and I am with a doubt, which the size of the bobbins? which wire I must use? e which in the distance between them? how many returns approximately?:confused: :confused: :confused:

you must calculate the inductance for 2khz tuning. If you are looking for large objects then every coil must be about 30x30 cm or 40x40 cm etc. The distance between two coils must be 80..100cm. If the coils are big and the distance between them is big then you can locate large objects deeper.

[kt315]

Coils are D-38 cm, 150 turns, D wire-0,4 mm. Voltage amplitude on TX coil is 120 V*

* take attention on it! are you agree that it is *superior*?!!
if you are not agree... then I AM SORRY :mad:

[ivconic]

KT315 was faster


KT315 You are faster in reply.
I haven't build a proper coils.In a few days I'll test it
and than report.I have noticed something else. There are two
pictures, one is IB/T/R or VLF and the other is a TX part of
Two Box we are speaking here about. Any simillarities !!??
Can we just use the first schematic and add two separate
coils and make Two Box? Can we use any other good IB and
use it as Two Box? Why not?
Somebody here asked (Roberto I think)for coil
calculations....I can offer presented formula.Is it good,
well dig that Yourself.Once I opened an original White's
coil.Cracked it and count windings.RX was 396 windings and
TX was 31, Feedback was 11 aprox. When I put known datas in
this formula, it gives me for RX 421 wind., for TX 30 aprox.
and for F.B. 10 aprox. So it seems that formula is good enough!
If it help U, than cool! About previous of my questions:
Can I use OA90 or simillar diodes.Germanium diodes do the
better job here.Demodulated signal is weak and decay after
a second or two...Thats why I asked.Other...I choose LM358,
'cose I saw it in Classic 3 do the job.Instead od 7812 I used
7810 cose of batteries of 12v.
that's all for now..regards