Whites Surf PI schematic

[escarabajo]

Hello Dimovnis, if you are replace the 2n3906 for BC337, is a mistake.
The 2N3906 is a PNP transistor and BC337 is NPN, you can replace the 2N3906 for BC556, BC557 or BC558, this transistors are the same type PNP, and the parameters are closer than 2N3906.
Be carefull with the Pins in the "BC" transistors are diferent from 2N3906.

I you see the 2n3906 with the flat side up, the pins are (from left to right) E B C

The "BC" transistors,seeing with the flat side up, the pins are , (from left to right) C B E

I hope this information can help you

Be patient.

Regards

Escarabajo.

[dimovnis]

Hello people. These days I have tried to do something but I did not succeed. I found that the BC337 hot. I replaced BC337 with new but still the same. I put the bc639 not heating up there, just one tone, and does nothing more.
Sorry about the poor ENGLISH

[satdaveuk]

Tea

Hello Friends,

Well if we where neigbours it was easy... a cup of coffy and some live to the scope...but as we are from al over the world this in not easy to do...
In the past I made from the Surf some different boards, build them and had no problems so far..but as other components can be used ..
Looking at al the posts about the surf I see that there are some problems here and there..
Also "Joop" had a problem with the sync around the ICL7660 and made a mod as follows ?

So it can be that a modification can help solving the problems some have ?

Look at the drawing...

Replace R3 for a resistor 1k5
Remove link from the +Batt to the 2N2906 and replace this link for a 100 ohm resistor
Remove R17 and the Diode
Drill a small hole in the ground track to place a cap from 220pF that has the other leg in the anode from the removed diode
Replace R5 for a resistor from 100 ohm.

Well I hope I have not made mistake's but... I hope that more off us will check this mod.. (If I had to eat al the mistake's I made in the past... ...)

Best regards.

Ap


[ATTACH]24121[/ATTACH]

Hi ApBerge

I drink Coffey but prefer a nice cup of strong Tea two sugars and a splash of milk .
The likes of you me and others like Simon Baker would be in and out of each others workshops quite regular I think if we were neighbors.
Far as modifications in general they are a good to play around with but only when your project is up and fully running as per original specification .
Ive noticed theres quite a few on here and across the forums doing modifications to projects because they cant get them to work correctly which is not the correct way to go about things and putting it bluntly is nothing more than a bodge job.
If your project is not working correctly on a proven design such as ApBerge lay files then theres a fault or faults that need to be addressed.
First things to check is your construction , if the problem doesn't lay there then look into component spec because it can only be one of them to things.
When constructing as Ive stipulated so many times don't just judge a component by whats on the label always check with relevant testing gear before installation so as to get a nice precision working project.

After that trying mods and experimenting is good practise.

Regards

[porkluvr]

Hello everyone. Its main surf.No sound, may have given some to help me. I looked at all the posts I have found a similar problem anywhere. thankful in advance

In your top photo it looks like you have three 1Ω resistors in series, totaling 3Ω.
IF that is your damping resistor you should have (depending on your coil) about 390Ω there.

[dimovnis]

Hello everyone. Its main surf.No sound, may have given some to help me. I looked at all the posts I have found a similar problem anywhere. thankful in advance

[david135]

Photos PCB tp adjustable headphones 9 v, 0.53v coils tp, tp turne 0v, thought change for IRF9640 or TIP42C TIP127 Thanks Hi

[kt315]

can you desolder all PCB and give pics of both sides? your pcb seems was water leaked...

[david135]

Greetings all, I got a broken surf original IP, but I can not fix it, streaming audio, dump resistor 330 TIP127, please tell me the tp control, thanks.

[sdesic]

These are the difference
I used trimmer 3k3 as R2,
my 7660 is smd, my 2N3906 is BC557C
R25 is two parallel resistors 10k
R34 is 140 ohms
D6 is 1N4007
C2 is 2200uF 25V

My IC's
HEF4093BP
HEF4066BP
LM358P
NE5534P
TS555CN
7660 ACBAZ

[sdesic]

here are few pictures of my battered Surf Pi Pro taking another modification

[sdesic]

Looks like I am the first to try this mod ... my Surf Pi Pro is not working anyway.

With this modifications it is not changed.

Replace R3 for a resistor 1k5 OK DONE
Remove link from the +Batt to the 2N2906 and replace this link for a 100 ohm resistor OK DONE
Remove R17 and the Diode OK DONE
Drill a small hole in the ground track to place a cap from 220pF that has the other leg in the anode from the removed diode OK DONE
Replace R5 for a resistor from 100 ohm. OK DONE

I have now have one spare diode, resistors 10k and 1k5 free for next project.

[bernte_one]

i have two complete surf pi pro xx here i think i can try the mod on one board and compare the difference

thanks for posting the mod

[ApBerg]

Thank you Dave and Ap for your help with this.
I am going to try few more days - it is snowing here so I can't do much.
My friends has told that he has old oscilloscope but no probes, if it works I could be able to post SurfPi pro condition soon.
Later today I will try few more things suggested by ApBerg.

Hello Friends,

Well if we where neigbours it was easy... a cup of coffy and some live to the scope...but as we are from al over the world this in not easy to do...
In the past I made from the Surf some different boards, build them and had no problems so far..but as other components can be used ..
Looking at al the posts about the surf I see that there are some problems here and there..
Also "Joop" had a problem with the sync around the ICL7660 and made a mod as follows ?

So it can be that a modification can help solving the problems some have ?

Look at the drawing...

Replace R3 for a resistor 1k5
Remove link from the +Batt to the 2N2906 and replace this link for a 100 ohm resistor
Remove R17 and the Diode
Drill a small hole in the ground track to place a cap from 220pF that has the other leg in the anode from the removed diode
Replace R5 for a resistor from 100 ohm.

Well I hope I have not made mistake's but... I hope that more off us will check this mod.. (If I had to eat al the mistake's I made in the past... ...)

Best regards.

Ap

[sdesic]

Part list

and the rest to go with it
Just realized ive already posted it all so just a repeat never mind better to much than to little.
Anyone want sprint layfiles of the single sided long board just ask'

Do you have part list for this project ?
Or it can be exported from layfiles ... please post

[sdesic]

Thank you Dave and Ap for your help with this.
I am going to try few more days - it is snowing here so I can't do much.
My friends has told that he has old oscilloscope but no probes, if it works I could be able to post SurfPi pro condition soon.
Later today I will try few more things suggested by ApBerg.