Surf PI Pro

[tvr]

Picked up a board and components to start building a Surf PI Pro. Looks like a lot of great reading to do here before I get started.

[WM6]

Looks like a lot of great reading to do here before I get started.

Half an year of reading, before asking couple of times answered question again.

[daverave]

Hello everybody!
I made the board of SurfXX by Apberg, and now I have a weak audio. It does work, but a very feint audio on detection. I substituted MPSA13 with BC517, couldn't find better replacement. Voltage of my batteries is around 11,30 volts.
Hows your audio on this SurfXX? I even made my own Piezo headphones but still a feint audio.

Did you solder a 10k resistor across the piezo otherwise you will not hear anything

[jotapota]

Help with my SM Pro DD please

Hello guys,

This is my first message, sorry if I am making a mistake typing in this thread, but I have spent a lot of time looking for a solution for my problem looking for it in different threads and I didn´t find it.

I bought a Surf pro DD from eBay, the seller gave me the parts list, but it's the same thing I can find in this forum, R36 does not appear.

I've seen other schemes where R36 appears, but it's not the same PCB of mine.

Apart from problem R36, there is a hole close to Q2 (IRF9640) I guess i have to leave it that way for using the PCB with two Coils (using a DD coil) TX and RX, but if i want to use it with a mono coil, What I have to do? Have I to make a connection between this hole and a resistor?

Sorry again (for my bad english as well), thank you so much!!!.

Regards from Spain!

http://i63.tinypic.com/14mylap.jpg
http://i68.tinypic.com/4t6nfn.jpg
http://i66.tinypic.com/2ii8kk1.jpg
http://i68.tinypic.com/2nqxjqg.jpg

[IMG][IMG]<a href="http://es.tinypic.com?ref=14mylap" target="_blank"><img src="http://i63.tinypic.com/14mylap.jpg" border="0" alt="Image and video hosting by TinyPic"></a>[/IMG][/IMG]
[IMG]<a href="http://es.tinypic.com?ref=4t6nfn" target="_blank"><img src="http://i68.tinypic.com/4t6nfn.jpg" border="0" alt="Image and video hosting by TinyPic"></a>[/IMG]
[IMG]<a href="http://es.tinypic.com?ref=2ii8kk1" target="_blank"><img src="http://i66.tinypic.com/2ii8kk1.jpg" border="0" alt="Image and video hosting by TinyPic"></a>[/IMG]
[IMG]<a href="http://es.tinypic.com?ref=2nqxjqg" target="_blank"><img src="http://i68.tinypic.com/2nqxjqg.jpg" border="0" alt="Image and video hosting by TinyPic"></a>[/IMG]

[jotapota]

The seller kindly gave me the answer, I guess most people here knows it but I write the solution in case anyone has the same problem:

Using with DD coil:
R36: 1K
It is not necessary to change anything else.

Using with mono coil:
Obviously R36 (damping resistor to L2) is not necessary anymore because we have just to use L1.
We have to conect R8 to the hole closest to the IRF9640.

I will continue reading and learning from the people who write here.

Now time to make some coils (Or at least try) hehe

Regards!

[seriall714]

Hello.
My circuit has no sound. If I only set delay resistor its making sound. I saw signal on scope but I couldn't understand what's wrong. Any idea?

[homefire]

Set the delay Resister? Elaborate.

[seriall714]

I success got a sound but it doesn't see iron. And which pin that I can see curve on scope ?

[homefire]

Look at the output of first op amp.

[seriall714]

it was working little bit under distance of normal (1euro=15cm) with iron discrimination. i just remove 1k pot instead of 1k resistor. than its gone. it sees 1euro at 1cm hardly. i guess my PCB has too much week solder
anyone has idea what there is no distance?

thanks

[homefire]

LOL, Put it back normal with the Pot. Check the damping on your coil. What you you using for the coil ?

[6666]

The coil appears to be wrapped around the pink plastic basket on the left of the picture.

[homefire]

Yea, I seen that but wasn't sure it that was what he was using. If so he was doing OK at 15cm. LOL

[seriall714]

coil is 0.55mm 23turns with 24cm diameter at picture pink plastic i guess my PCB is not good (by iron transfer)

I saw NE5534 (first opamp output) on scope here;

20uS every square on scope;



1euro = 1cm distance i try to set delay pots but nothing chanced

[Xtrem]

Try to measure at the center pin of the delay pot, due to the setting it must change from 0-5vdc.
May be the problem is on the pot.