surf pi 1.2 problem

[kalaka]

Hello to all

first sorry for my bad english (translate with google)

i am noob with electronics and i fix the surf pi 1.2 kit.i make 26cm coil with 26turns and 0,45 wire.my problem is the surf pi dont response with sound if i put metal over the coil.i read others problems in the forum and i measurement few pins.

the results:
5534 pin7 / 4,92volt
358 pin8 / 4,92volt
5534 pin4 / -4,61volt
358 pin4 / -4,61volt
in tp2 i regulation to have 0volt.

if i regulation tp2 to -1,60volt i have sound only for iron at 10-15cm,silver/gold response only if i touch the coil.
i spending hours but I could not fix it.

[porkluvr]

I think you have too many turns for what coil diameter you chose. My coil calculator program says you made about 500uH. You should shoot for something around 230uH.

Try 16 or 17 turns.

[kalaka]

what program can i use to see the uH?

[Qiaozhi]

what program can i use to see the uH?

Coil Calculator

[kalaka]

my friends i make 17 turns coil but the same problem,the surf pi dont response (tp2 0volt).
i think the kit has problem but i do not know where is the problem.

[kasperfish]

Hi,

I'm also a noob and had problems before. I learned that it is very difficult to "pinpoint" were the problem is without an O-scope. If you are sure that all components are in the right place (like I did) you could try replacing your ICs, it solved my problem. However if you are not 100% sure about the components placement it would be a good idea to post some high res pictures from your board. Also check all your connections (pots, coil and solder points) to eliminate there is a problem with it.
Yesterday I soldered my second surf pi together and it wasn't working either. After checking and double checking I noticed that the speaker and a potmeter were connected the wrong way. Just want to say that it could be something really stupid even if you already checked everything.

[Qiaozhi]

my friends i make 17 turns coil but the same problem,the surf pi dont response (tp2 0volt).
i think the kit has problem but i do not know where is the problem.

The Surf-PI is relatively simple in comparison to many other designs, but you need to be careful during the construction. One of the common errors is to simply solder all the components onto the PCB, then switch on, and expect it to work. As kasperfish said, you really do need to have access to an oscilloscope. Obviously, some people have managed to successfully construct the Surf-PI and get it working with only a multimeter, but they are are few when compared to those who have ended up with problems.

At this point, you should carefully check that you have fitted all components in their correct positions and orientation. Also, check under the board with an eyeglass for any short or open circuits. If you cannot spot the fault, then check the power supplies with a multimeter. Failing that, find a friend with a scope.

[kalaka]

friends i take 7 photo with digital camera to see the pcb.

1 http://postimg.org/image/rlcopkhsh/full/
2 http://postimg.org/image/9ml9vf0dv/full/
3 http://postimg.org/image/7odqu1px7/full/
4 http://postimg.org/image/sukbgjac5/full/
5 http://postimg.org/image/nwzfkn643/full/
6 http://postimg.org/image/ckubze8id/full/
7 http://postimg.org/image/xzhrbtz27/full/

[sinclairuser]

a few things to try, the delay wires dont look right (could be camera illusion), and its confusing making them all same colour anyway.
the chips dont look seated in the sockets right( some crooked some not snapped in).
all that flux and crud on the underside of your board needs cleaning off (i use alcohol but you need to do it straight after soldering), one of the lads might have a better way of getting it off if its dry.
sockets i only use sockets to get it running, once running i remove them and solder chips directly (unless its a particular chip thats prone to need changing then i use a socket but only that chip).
i'm serious about not snapping chips in, it can make it work incorrectly.
apart from those few bits it looks not too bad at all.

[kalaka]

the first time who construction the pcb,i put 306e potentiometer but had the same problem,now i put the 100k potentiometer.
the chips pulled out and placed them but nothing doing.

sorry for my english (google translate)

[kasperfish]

hi,

are you sure R11, R22 and R23 are 22K resistors? It seems to me that they are 22Ω (0.022K) resistors.

frist band red, second band red, third band black gives 22Ω in the resistor calculator:
http://www.robotroom.com/Calculators...alculator.aspx

Also a few notes about the pcb:

1) R14 and R13 are almost touching each other.
2) R6 is dangerously close to the bridge you soldered. This bridge is unnecessary because it is hard wired in the pcb. It is better to mount R6 vertically instead of horizontally. You only need to solder 2 bridges that are marked with a white line (but it doesn't matter if you soldered the other bridges too)


grtz

[porkluvr]

hi,

are you sure R11, R22 and R23 are 22K resistors? It seems to me that they are 22Ω (0.022K) resistors.

frist band red, second band red, third band black gives 22Ω in the resistor calculator:
http://www.robotroom.com/Calculators...alculator.aspx

grtz

Hmmm, how do I say this... one percent (1%) tolerance resistors necessarily have five bands. The first three bands describe significant digits and the fourth band is the multiplier. So, red red black red, would be 220x100 = 22k. Band five is the tolerance.

[Silver Dollar]

I've never built the Surf PI but I wonder if these two jumpers are correct?



There's no silkscreen on the board calling for them...

[kasperfish]

Hmmm, how do I say this... one percent (1%) tolerance resistors necessarily have five bands. The first three bands describe significant digits and the fourth band is the multiplier. So, red red black red, would be 220x100 = 22k. Band five is the tolerance.

Yes, I'm no expert at this. I only can say that my resistors have a different color code (red, red, orange, brown) and they are 22K for sure. I didn't know it is possible that different color codes can have the same resistor value. http://www.hobby-hour.com/electronic...calculator.php


@silver Dollar: Only the marked solder bridges on the silk screen are necessary. However it doesn't matter that the others are soldered too.

[kalaka]

r11 and r23 in my photo is not 22K resistors?it is wrong resistors?i find this resistors inside bag kit.
r22 in silverdog partslist write 100K. http://www.silverdog.co.uk/shop/imag.../partslist.txt