Surf PI Oscilloscope reading

[petere]

Hi I have just built a working surf pi and basket weave coil. I can get a signal from a small piece of gold at about 5-6 cm. The only oscillosope I have access to is a pc sound card type and have attached photos of the signals. the first one from pin 3 on U1 and the second one is from pin 13 on U7. Do the signals show anything about how the detector is working or should I just presume it is about as good as I can expect it will be without better test equipment? I have adjusted the offset to 0v and the delay till I could get a signal from the small nugget I have. I have learned a lot since I joined this forum and would like to thank all the contributors for their efforts.

Cheers Peter

[6666]

pc sound card type

They do not work well, you need a better oscilloscope to see true wave form but if you are getting a small piece of gold at about 5-6 cm you are on the right track.

[petere]

Yes I guess I was just trying to get out of buying one. Do you think one of these would be OK?

http://www.ebay.com.au/itm/271648335...%3AMEBIDX%3AIT

[6666]

That appears to be only one channel you really need a two channel to be most usefull.

[petere]

OK Thanks. Bit more research.

[bernte_one]

poscope mega1

[Qiaozhi]

Yes I guess I was just trying to get out of buying one. Do you think one of these would be OK?

http://www.ebay.com.au/itm/271648335...%3AMEBIDX%3AIT

It only has a 4MHz bandwidth and a sample rate of 50Ms/s.
You need to look for a 2-channel scope with at least 20MHz bandwidth and 200Ms/s, or preferably better.

[petere]

Bit the bullet and bought an oscilloscope. Been a sharp learning curve over the last few days. Can somebody tell me if I am on the right track here. I have the trigger on pin 3 of U1 & probe on Pin 13 of U7. Does the trace look OK? Also how do I tell how fast the coil is?
Thanks for your help.
Cheers Peter