2 boxxxx :)

[Igor MN]

kt315 ?

Hi kt315,i need again Your help.Tell me with preccission what are the common name of parts (written in russion ) in T/R Locator,and can You translate text about making coils and stuff on this adress http://sevzirfo.narod.ru/md.htm

Thanks in advance

PS. i was learning russian language in high school,but was a bad student

[okantex]

another Question

why two box TR detectors are deeper then normal TR detectors?
what makes them powerfull?

[Geo]

Hi Geo,i can't make this T/R becouse,i still dont know if shilding is neccessary,and wright european marks of parts in schematics.whitch TO-220 iz best for him (irf 740 ?)\
Did You build one?if U tell me more about all construction,and sensitivity
Thanks

Hi Igor. The transistors are not critical so you can use BD139 and BD140 for KT815 and KT816,814 and 2N2222a for KT315. The coils do not need shielding.
I have build 3 two box detectors.They are easy in use and very sensitive at large objects.The only critical are the coils adjust who must be vertical between them.

Geo

[Geo]

Hi GEO
do u remember my previous mail with drawings .about what I said we found coin from 4 meters(coin was inside of a small closed mud cup that when we opened it my friends hand burned because of gas inside.so think coin at a size of cup because of oxidation effect)
that machine's antenna was in this manner.transmitter and reciever were in different axis.and in my opinion it's frequency was 50Mhz and it was spectral frequency analyzer.

Yes i remember but there is a diference between coin and cup.I think that for a cup the max depth is 1-1.5m.I know that for detecting in the ground the max frequency is 500 KHz.Signal of bigger frequency does not have infiltration in the ground.

why two box TR detectors are deeper then normal TR detectors?
what makes them powerfull?.

Two box detectors are TR detectors with the difference that the receiver receive signal only when it is reflected on a metal in the ground.This is the reason who have the coils vertical between them.The transmitter has much power so the signal is stronger and the detector is deeper. You can read "two box IB detector or deep seeking metal locator" files from Carl's site.
http://www.thunting.com/cgi-bin/geot...e=projects.dat
Geo

[Roberto]

2 box pcb!!!

if I will be able to help somebody with this I go here...




Roberto- Brasil.

[Roberto]

pcb

if I will be able to help somebody with this I go here...



Roberto -Brasil

[chemelec]

Has anyone ever built the Treasure Witcher by Charles D Rakes?

The Write-up Looked pretty good.
If anyone knows how good did it work, Let me know?

I would like a comparison for below.

I Realize that CA3035 IC is no longer available. Hasn't been for about 20 years.
But I have re-designed that circuit with all descrete parts.
Haven't got it together yet, Just started working on a circuit board now.
Looks like the Reciever board is pretty small.
A 10 transistor amp, about 1.5 X 3 inches.
Frequency response and gain appears Close to the IC Specs.

Assuming it works good, I will publish full details.

[Geo]

Has anyone ever built the Treasure Witcher by Charles D Rakes?

The Write-up Looked pretty good.
If anyone knows how good did it work, Let me know?

I would like a comparison for below.

I Realize that CA3035 IC is no longer available. Hasn't been for about 20 years.
But I have re-designed that circuit with all descrete parts.
Haven't got it together yet, Just started working on a circuit board now.
Looks like the Reciever board is pretty small.
A 10 transistor amp, about 1.5 X 3 inches.
Frequency response and gain appears Close to the IC Specs.

Assuming it works good, I will publish full details.

Hi Chemelec. I have build it before 22 years ago (on 1983 if i remember good).It was a good detector for large objects (larger than a soda can).
You must re-design the tsansmitter because there is problem with transistor Q1 and unijunction tsansistor Q2. Good luck.

Geo

[okantex]

Hi GEO
I read that files ,thanks for your offer.
in my unit there were 2.7 pikofarad condensators which carries frequency to Mhz levels.
in my receiver unit thre were two windings that were connected eachother paralel. one of them is like in picture.and other is around the u cores in rectangular position( in channels around the cores)which is not drawn here.this not drawn one has just two turn around .and it is decreaseing the total inductance.if you calculate you can find approximate frequancy of operating.
I tried and found something like 50 Mhz.(I am not electronition and can make mistake)( you can see u cores here http://www.aet.com.pl/en/ferryt/rdzenie_u3.html
and something else ;receiver and transmitter were in a small volume.like two mallboro cigarette box (which have 20 piece in ).
QUESTİON ;why , while transmitter and receiver were coming closer penetration to ground decreases? I can understand it's mantality
(my units pcb looks like similar to this two box detectors.,except condensator values and TR designs)

[chemelec]

Hi Chemelec. I have build it before 22 years ago (on 1983 if i remember good).It was a good detector for large objects (larger than a soda can).
You must re-design the tsansmitter because there is problem with transistor Q1 and unijunction tsansistor Q2. Good luck.

Geo

Yes I had Planned on Redesigning the Transmitter Also. I hate UJT's
Possibly a Modulated Cmos circuit.

PCB Done.
Should have it assembled this afternoon and see if the reciever part works.

Gary

[Geo]

Hi GEO

something else ;receiver and transmitter were in a small volume.like two mallboro cigarette box (which have 20 piece in ).
QUESTİON ;why , while transmitter and receiver were coming closer penetration to ground decreases? I can understand it's mantality
(my units pcb looks like similar to this two box detectors.,except condensator values and TR designs)

Hi okantex. I do not know why when transmitter and receiver were coming closer then penetration to ground decreases? But i know that when the coils coming closer then we can detect smaller objects.For an example if we construct the coils about 10cm x 10cm and at a distance of 30..40cm between them then we can detect a coin 25mm. I attach a file with the coils of a 2box detector who i manufactured 5 years ago.I found it today in a wardrobe.
Geo

[Geo]

Yes I had Planned on Redesigning the Transmitter Also. I hate UJT's
Possibly a Modulated Cmos circuit.

PCB Done.
Should have it assembled this afternoon and see if the reciever part works.

Gary

Hi Gary.Try the transmitter of Sevzirfo T_R Locator. From my experience when you will finish the detector the receiver must receive the Xmt signal (with coils parallel not vertical) at a distance at 6..7m at least. Good luck.
Geo

[chemelec]

Hi Gary! I think that is great idea,becouse i am a builder not a inventor can't wait for You to finish.The sooner the better
Kt 315,You are not making it easy to me sow same changes on schematics made from You ( U1D is missing) ,is that supouse to be bi like that?
greetings from Igor

I Put the PCB Together Yesterday. One Part of the Circuit Doesn't work.
I'm trying to find my Error on the board.
I Proto typed all the stages before hand and they worked that way.
I Got a Small error on it Somewhere.

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

[chemelec]

I found out I missed a trace. Now it Works but Oscillates badly as soon as I turn up the gain. See Photo of this proto.

This Somewhat Duplicates the CA3035 IC, plus the additional parts in the reciever.

The first 3 transistors is stage 1.
The next four are stage 3
The Last 3 are Stage 3
Each stage has a gain greater than 40 DB and a bandwidth of about 250 kHz.

I have now re-desined the board and hopefully fixed the problems.

Gary

[okantex]

Question for Chemelec and Geo

why do not you increase frequency and use ferrite core to get powerfull transmitter signal.with ferrite core you can obtain highly consentrated round wave structures that can penetrate ground easy.ferrite core makes small field circules biger and stronger which gives the same effect with low frequency 's optimum field effect.
and Mr chemelec the ujt which you do not like gives sudden increase in current and also sudden creation of big field lines that small ones have to be bigger with this effect .These are my opinions ıf I am wrong ,please tell me the true teory.
Mr Chemelec please do not give up ujt .
and Mr Geo did you buıld serzirfo in past.and the pcb of chemelec .is it correct .did you check it?I could not undestand it.in schamtic there is a current meter but in pcb I could not find it's outputs.
have I nice day all