Surf PI Pro

[Geo]

Hi Geo,

happy to hear that your detector work

which resistor you mean to change with 100k pot do you mean R2 ??

could you please send us the schematic that you worked from and any other updates you made ??

also please if you can send us clear photo of your detector

thanks in advance

Hi.
I mean the potentiometer P2.
See the post of 6666.

[6666]

Geo
The lack of sensitivity seems to be a common problem,
however I have a 10k pot for P2 and all works ok for me.


P1 = 100k [Trimmer on PCB]
P2 = 10k [Tune: Potentiometer]
P3 = 100k [Delay: Trimmer on PCB]
P4 = 1k [Volume: Trimmer on PCB or Potentiometer]

[Jose]

Hi jose
My coil is 20cm, 0.4, 22 turns

and R1 is 100k ,C1 is 22nf

my R3 is 3.3k and C16 is 100n is it okay ??

another thing jose you said you have working surf pi
could you please please upload the schematic and the pcb you made from
and if you can upload clear photo of your surf pi

thanks

The values are well, do not understand why the difference in tensions.
Okay installed the IRF9640? or perhaps damaged.
Works well the threshold, can be set to silent or very low?. if not so, replace P5, on the other 100K as Geo says.
I'll take some pictures later and publish
Jose

[Mohamed Ghitas]

Hi Geo, if you mean the threshold potentiometer, tube the same problem, but I replace R18 for another 22K, and it worked well, This already wrote before.
Mohamed, 135mA seems a bit high, I'm using 10K for R2 and adjusted to 6.7K for a pulse width greater than 100 us, the consumption is 110 mA.
I fit that way because my coil is 380 uH.
The original Pi surf fits about 50 us. and the coil is less than 300 uH, so consumption is less than 100 mA.
Mohamed, your coil may have a problem, or maybe there is an error in the values of R1 and C1.
Jose

Hi jose
My coil is 20cm, 0.4, 22 turns

and R1 is 100k ,C1 is 22nf

my R3 is 3.3k and C16 is 100n is it okay ??

another thing jose you said you have working surf pi
could you please please upload the schematic and the pcb you made from
and if you can upload clear photo of your surf pi and your coil

thanks

[Jose]

Hi Geo, if you mean the threshold potentiometer, tube the same problem, but I replace R18 for another 22K, and it worked well, This already wrote before.
Mohamed, 135mA seems a bit high, I'm using 10K for R2 and adjusted to 6.7K for a pulse width greater than 100 us, the consumption is 110 mA.
I fit that way because my coil is 380 uH.
The original Pi surf fits about 50 us. and the coil is less than 300 uH, so consumption is less than 100 mA.
Mohamed, your coil may have a problem, or maybe there is an error in the values of R1 and C1.
Jose

[Mohamed Ghitas]

Hello.
Today i finished the Suf on a pcb ordered from Silverdog.
The detector worked from first time but the sensitivity was not good. After a fine adjusting to delay and offset trimers it had the ability to detect a coin at 12.. 13 cm only. I saw that there was not response when i changed the tune potentiometer. So the problem was near it...
After some time i saw that with the resistors that Silverdog gives must use 100k potentiometer. BUT Silverdog writes at part list for surf at his site that the potentiometer must be 10K. I replaced it with 100k and all OK. Another very good PI detector for underwater detecting.

Regards

Hi Geo,

happy to hear that your detector work

which resistor you mean to change with 100k pot do you mean R2 ??

could you please send us the schematic that you worked from and any other updates you made ??

also please if you can send us clear photo of your detector

thanks in advance

[Geo]

Be Carefull

Hello.
Today i finished the Suf on a pcb ordered from Silverdog.
The detector worked from first time but the sensitivity was not good. After a fine adjusting to delay and offset trimers it had the ability to detect a coin at 12.. 13 cm only. I saw that there was not response when i changed the tune potentiometer. So the problem was near it...
After some time i saw that with the resistors that Silverdog gives must use 100k potentiometer. BUT Silverdog writes at part list for surf at his site that the potentiometer must be 10K. I replaced it with 100k and all OK. Another very good PI detector for underwater detecting.

Regards

[Mohamed Ghitas]

Front Preamplifier, as I have understood this is named to the first amplifier, consists of the NE5534 and its associated circuitry.
adjustment P1 or R10 depending the schema, with the coil connected, to check 0 volts on pin 6. Bringing big metal, such as a can of coke in the vicinity of the coil, the voltage should be increased to "0.5 volts negative."
The tension in D (0.10 Volts) the IRF9640 is low compared with my Surf PI, where I can vary between 0.5 and 1 volts, according adjusting R2.
Adjust R2 trying to get to the above values (0.5 a 1 Volts in D), and check the total current he should go between 80-110 mA. in more or less.
Excuse my bad English.
Jose

hi Jose,
the maximum volt i can get on D of IRF9640 is only 0.32 v with R2 9.44k shall i increase it iam using R2 Pot. 10k
do you think the problem is here ??

and the total current is 134 mA is it ok ??

[paku]

Any One Have Make The Good Coil for Surf PI What coil size and

[Jose]

Front Preamplifier, as I have understood this is named to the first amplifier, consists of the NE5534 and its associated circuitry.
adjustment P1 or R10 depending the schema, with the coil connected, to check 0 volts on pin 6. Bringing big metal, such as a can of coke in the vicinity of the coil, the voltage should be increased to "0.5 volts negative."
The tension in D (0.10 Volts) the IRF9640 is low compared with my Surf PI, where I can vary between 0.5 and 1 volts, according adjusting R2.
Adjust R2 trying to get to the above values (0.5 a 1 Volts in D), and check the total current he should go between 80-110 mA. in more or less.
Excuse my bad English.
Jose

[Mohamed Ghitas]

Mohamed, I apologize to you all the forum, for the mistake, it must be "-3.8 Volts" collector of Q1, ended check with my Surf PI. Moving a little R2, (TX pulse width) in my Surf Pi, came to the "-3.6 volts", so I understand that Q1 is working well in your detector. You will have to search elsewhere failure. Also check the front. Coil connected, the voltage at pin No. 6 of 5534, should be near 0 volts, approaching oversized metal to the coil, the tension on the same pin, must be "-0.5 volts" (negative 0.5 volts). Hope I'm not wrong again. Jose

Jose, thanks for your replay
no problem, happy that my 2n3906 works fine what do you mean by front ??
pin6 at 5534 zero volt if you mean by tension on the same pin that when i put metal close to the coil and measure pin 6 it gives "-0.06" and what about IRF9640
G:10.81
D:0.10
S:12.39
is it ok ??

[Jose]

Mohamed, I apologize to you all the forum, for the mistake, it must be "-3.8 Volts" collector of Q1, ended check with my Surf PI.
Moving a little R2, (TX pulse width) in my Surf Pi, came to the "-3.6 volts", so I understand that Q1 is working well in your detector.
You will have to search elsewhere failure.
Also check the front.
Coil connected, the voltage at pin No. 6 of 5534, should be near 0 volts, approaching oversized metal to the coil, the tension on the same pin, must be "-0.5 volts" (negative 0.5 volts).
Hope I'm not wrong again.
Jose

[Mohamed Ghitas]

You say "-3.3 Volts", I will check with my Surf Pi, and then I answer. Jose

thanks

[Jose]

You say "-3.3 Volts", I will check with my Surf Pi, and then I answer.
Jose

[Mohamed Ghitas]

hi Jose you said this before "I had problems with the Surf PI, already discuss elsewhere in the forum, but I repeat again, to try and help those in trouble. The cause was a malfunction of T1, apparently by the type of 555 that I'm using, producing poor bias of this transistor This transistor (T1), saturated and collector pulses are weak or low amplitude making it run incorrectly the 4093, the pulse delay, appears immediately after the pulse TX, (no delay work), producing MD malfunction. The best way to check if T1 works well, is with the oscilloscope. Without oscilloscope, you can measure the voltage between collector T1 and GND, and should be around 3.8 volts. If the voltage is higher, in my case was 11 volts, then T1 is not working properly. I solved the failure by installing a 3.3K resistor between emitter and base of T1. Jose " in my case T1 emitter measures "-3.30v" so what do you think the problem is ?? Mohamed