Anyone have Surf PI Pro Schematic?

[bklein]

Anyone have a schematic of the Surf PI Pro? The board is 505-0227 as shown in the attached photo. The timings and signals seem to be quite different than I see on the PI clone design. But maybe that's why this one doesn't work too well... I had to repair several traces etc. as this board had some salt water corrosion issues. There is a schematic floating around of the Surf PI with hand markings on it - but those aren't very clear and may or may not be similar to this board. The marketing description says that there is a gain control and Vsat. So I would think a gain control would be on the 5534 circuit - but no. Sure, I could sit down for 4 hours and figure this out, but maybe someone already has...

Barry

[homefire]

Yur photo did not make it! I have the circuit board factory built.

[bklein]

The photo shows up here (now at work pc).

[bklein]

Tonite I went through the 555, mosfet, and preamp circuits and matched them up pretty well to one of the many schematics I have of PI's. Tomorrow I'll work on the 4093/4066 areas - they seem different than my schematics. Have you taken any scope shots of timings of yours?

[homefire]

Your Photo is not showing on the Forum!

[bklein]

It is showing as far as I have seen on several pc's. Maybe you need to change your screen resolution or something:

[satdaveuk]

show the other side, will help alot

[bklein]

Ok, here's the underside. Not sure how that helps... I'm hoping you are not trying to come up with a schematic off the photos. Traces go under the chips and it is hard enough when you have the board in front of you!

[bklein]

So far:
Output of 555 pin 3 is 55uS neg pulse.
Output of the first 4093 NANDgate is 14uS pos pulse.
Outputs of two 4093 NAND gates to 4066 are 38uS and 41uS pos pulses.
Output of last 4093 NAND gate to audio 4066 sw is 180uS.
Now past that stuff it gets tricky. Sum resistor to + input is 10K while - input resistor is 1K. 470K resistors + input to gnd and feedback. .22uf caps instead of .47uf.
Still working on the last op amp stage.
I may have the two pots swapped by mistake... Their functions are labeled as Gain and Tuner not DISC and Threshold.

[bklein]

Here is a photo of the pulse timing. These two pulses are fixed in timing with one another - no DISC control to move them out for example. The trimpot sets the timing of them against the coil feedback signal. The GAIN pot does seem to affect the output gain and the TUNER pot adjusts the DC threshold to gate the audio. This thing is probably working correctly now that I replaced the feedline with USB cable. I don't have the pot circuitry schematic figured out yet. I want to go back and compare this preamp output with the Clone PI to verify it's ok. Comments? Anything you want to see before I pack this up?

[bklein]

Well, it doesn't work right. It seems ok up to and including the diff integrator but after that is where the design gets unique and this pcb had trace damage. Jeez a correct schematic would be nice...

[homefire]

Here , Hope this is what you need.

[bklein]

Thanks, I had that circuit and some like it - like someone's workbench notes...
The circuit of the Pro differs.
Regardless, this morning I pulled out the 4093 and 4066, put sockets in, and put in new parts and it is working!
Moderator, feel free to just delete this thread....

[TH Jim]

Hi,

Can you tell us what differences you've found between the pro version and the one we have all built here on the forum?

Many thanks.

Regards Jim.

[bernte_one]

hello homefire

can you give component side layer or partplacing plan for your surf pi2 layout?

please

or same like surf pi normal but other arrangement?

regards