Surf PI Pro

[deathmatch]

Yes, certainly. It will be simple in case of scheme start without this resistor the metal detector to have smaller sensitivity. I assembled here such simple pulse metal detector.
In this simple scheme only threshold strengthening is adjusted. I achieved result of sensitivity in 23 centimeters but that took a subject at a bigger depth to us 2 ways are given: to increase energy of an impulse of a rating or to lift cascade strengthening. The first way demands bigger power consumption, - drag the automobile accumulator on the cart, and the second - doesn't demand a big expense.
I will notice one serious lack of the scheme: to the 3pin of the 555th timer it was necessary to attach one more transistor and already through it to give on a gate 9640. It is so possible to receive more cool impulses at first and I will fall down
____________________________________________
Itself now slowly I do Surf XX. I sealed condensers at first. I decided to check and here a surprise: polymeric condensers.
One was short-circuited, and two others changed capacities.
I feel it is necessary to find my boxes with palladium condensers from the disassembled soviet military equipment.

[sdesic]

R3 disconnected no sound in headphones.
When volume is max there is sound - faint constant sound like siren.
I think volume pot is heating up.
Pin 2 4066 has 0V
Pin 2 4066 has 0V
Measuring pin 11 on 4066 produces siren in phones.

[sdesic]

You say to disconnect R3 and to try powering without it ?

[deathmatch]

I to you once again repeat: seal the loudspeaker instead of the search coil. It is admissible during control and will help to solve your problem.
Still try in the following places according to the scheme:
4066 pin 11, pin 2, pin 4. The same will sound there as in the coil. Disconnect R3. If on pins 11,12.4 no signal - then delay cascade work.

[deathmatch]

Many trifles can give similar effect.
For example gumboil. Though the producer writes that gumboil doesn't demand washing. And upon washing it is necessary: simply after the soldering there is resistance between paths which aren't connected with each other.
As a result on megaohms pro-calls appear figures... And they shouldn't be
And still council: you can simply disconnect a delay from work of the 4066th chip.
For this purpose you should disconnect temporarily R3 from the 555th chip.

[sdesic]

Coil and other thing are not moving in relation to each other.
Without coil there is same sound.

[deathmatch]

sdesic I think that cascade with 555timer and IRF9640 not work correctly. Change search coil on the speaker. If you listen sound -use frequency meter. If frequency from 400 to 800 Gerz - your surf work properly.The generation after 555 maybe interrupted if IRF not open\closed and not full open closed.///
But second version - local electromagnetic field(hitch) ///walk to park\forest and check construction.

[sdesic]

Surf Pi Pro - no siren when I disconnect tc555.

Also if I replace C1 22nF with different one it changes sound frequency,
if no C1 is connected there is no sound.
Then Sens pot has some effect - from silence to weard sound...

Anyone ?

[sdesic]

Can I convert Surf Pi Pro to Surf Pi
using Surf Pi Pro PCB by disconnecting parts ?

[kt315]

What is the difference between this and the surf pi duel field?

dual field one is selling for more price.

[dfxmadness]

What is the difference between this and the surf pi duel field?

[sdesic]

this thread is marked Surf Pi Pro
it's simplified version of SurfMaster Pi (Pro)

[dfxmadness]

Is this the surf pi duel field that whites sells?

[sdesic]

PCB and parts side

[sdesic]

changed bc879 to MPSA13 with orientation right and I got siren with variable volume - volume pot is working
with or without coin it is siren
pots are not responding
offset trimmer also does nothing
I have 55mV at coil