deep surfmaster and large coil

[ossamaussama]

hi every one


i try to use surf master with coil .5 m * .5 m coil

it work and detect paint can about 1.5 meter in air

1-put variable resistor 20 k in series with 3.3 k in transmitter circuit
Measure current draw by the circuit is should be around .2 amp

You have to use 12 volts (4 amp lead acid battery)


With coil 23 turns and .5*.5 m

Damping resistor 1K


And in the last stage

That is the out put of integrator

Pin 7 of L358 opamp

Connect audio VCO circuit (copy it from delta pulse schematic)

It work very stable and sound like delta pulse


Very sensitive

Important note: it is better to connect analogue meter with 1k to pin 7 of LM357 to make sure that its working in active region

Say 3.6 volts


I will post full schematic next time

I need help about coil shielding

[Sean_Goddard]

Plenty on this forum about that. Check the PI section.

[Geo]

Read this!!

http://www.geotech1.com/pages/metdet...s/FastCoil.pdf

[ossamaussama]

circuit diagram

http://www.m5zn.com/uploads/2010/11/...d0pozx3d5u.jpg

hello every one

i will accept any idea

surf master is stable device and simpler than others

my idea is why not to use it for deep seeking

by use larger coil and more TX power

the Vco audio circuit is better than move detection in original surfmaster

for large coil becuase in large coil you cannot move as fast as need


when i try this modification it is faster than delta pulse

[nelson]

Good work ossamaussama.

Also the link you posted is broken for me. So can you posted again to see what your work is like?
In advance, many thanks.
Best regards
Nelson


quote=ossamaussama;118569]http://www.m5zn.com/uploads/2010/11/...d0pozx3d5u.jpg

hello every one

i will accept any idea

surf master is stable device and simpler than others

my idea is why not to use it for deep seeking

by use larger coil and more TX power

the Vco audio circuit is better than move detection in original surfmaster

for large coil becuase in large coil you cannot move as fast as need


when i try this modification it is faster than delta pulse[/quote]

[ossamaussama]

Good work ossamaussama.

Also the link you posted is broken for me. So can you posted again to see what your work is like?
In advance, many thanks.
Best regards
Nelson


quote=ossamaussama;118569]http://www.m5zn.com/uploads/2010/11/...d0pozx3d5u.jpg

hello every one

i will accept any idea

surf master is stable device and simpler than others

my idea is why not to use it for deep seeking

by use larger coil and more TX power

the Vco audio circuit is better than move detection in original surfmaster

for large coil becuase in large coil you cannot move as fast as need


when i try this modification it is faster than delta pulse

[/quote]

just clik on the link and you will see the photo save it

[ossamaussama]

http://www.m5zn.com/uploads/2010/11/...d0pozx3d5u.jpg

[WM6]

http://www.m5zn.com/uploads/2010/11/...d0pozx3d5u.jpg

For me this second link is not working but first one was ok.

[ossamaussama]

dont forget

dont forget to use heat sink for TIP32C

[Mrand]

Probably you will be not especially satisfied. SM-PI is designed to the detection of small objects which can be found on the beach. If in spite of all you want to experiment, you must make some more changes.
1. Instead R13 - 1k put in the resistor 1.10k (1%).
2. Serially with R14 to include 10-turn miniature potentiometer 200ohm. He will permit sensitively to compensate for the reaction of the earth magnetic field.
3. The value R28 must be enlarge. There will be the better reaction on the large objects.
4. The value C5 and C6 must be enlarged too. Will this slow down the dynamics of the detector and will enlarge the noise immunity. The capacitors we select with the tolerance at least 5%.
Successes in experiments.
Mrand

[ossamaussama]

Probably you will be not especially satisfied. SM-PI is designed to the detection of small objects which can be found on the beach. If in spite of all you want to experiment, you must make some more changes.
1. Instead R13 - 1k put in the resistor 1.10k (1%).
2. Serially with R14 to include 10-turn miniature potentiometer 200ohm. He will permit sensitively to compensate for the reaction of the earth magnetic field.
3. The value R28 must be enlarge. There will be the better reaction on the large objects.
4. The value C5 and C6 must be enlarged too. Will this slow down the dynamics of the detector and will enlarge the noise immunity. The capacitors we select with the tolerance at least 5%.
Successes in experiments.
Mrand

thanks mrand so much for your idea


i already test the device it work as good as delta pulse put faster responce

but it sensitive to earth so i work above the erth around 10 cm

ok less depth under ground i lose about 23 cm


but it is work

i will try changes as you told me


and put the result


thanks

ossamaussama

[ossamaussama]

results

Probably you will be not especially satisfied. SM-PI is designed to the detection of small objects which can be found on the beach. If in spite of all you want to experiment, you must make some more changes.
1. Instead R13 - 1k put in the resistor 1.10k (1%).
2. Serially with R14 to include 10-turn miniature potentiometer 200ohm. He will permit sensitively to compensate for the reaction of the earth magnetic field.
3. The value R28 must be enlarge. There will be the better reaction on the large objects.
4. The value C5 and C6 must be enlarged too. Will this slow down the dynamics of the detector and will enlarge the noise immunity. The capacitors we select with the tolerance at least 5%.
Successes in experiments.
Mrand

hi mrand


after changing r28 to 300 k it detect more for large object but it seem sensitive to ground


i do ground balance Manually

max depth in air is about 1.7 meter

i will try Shield

may ground effect reduced

[Rumcajs]

Hi friend,

for bigger deepth must be increase output power. Please change to 1000 microFarad tank capacitor to 2200microF, or better, when adding paralel an 2nd 1000microF (this decrease the resistance of tank capacitor).

For deep search slower fequency is recommended than original. 100-300Hz is good, i think.

Good hunting!