Whites Surf PI schematic

[chemelec]

This might give you a better idea.

[homefire]

Yea, Much better. My hearing is messed up but I could deal with that.

[Tim]

Yes, thanks Gary. All food for thought. Personally I appreciate your website, and input here. Sorry it is losing its lustre for you. I have had an extended hiatus from the sparks and smoke- sometimes that is all that is need for re-invigoration. Heading off to a permanent bush job in the new year and taking my electronics kit with me. I am going to try your "improved" BFO, with the oscillator substituted with Colin Mitchells circuit 8, as an appetiser.
The Surf sound sounds great to me, very clear and positive.

[Old cart]

I agree and sorry you no longer find it fun.

[seadoggy]

Any one have problem with surf pi when swing coil make sound??,also when i close to land make sound my surf pi is not stable at ground to much noise make!what can be a problem??

[seadoggy]

sorry for multiple posts guys i make this version of Surf pi.

[kt315]

i close to land -- what land??? your metals extremely overinfected yard new home? WHERE?

[seadoggy]

i close to land -- what land??? your metals extremely overinfected yard new home? WHERE?

I think when i go outside from home with surf pi it is not stable,every time when i swing with coil make sound at every end of swing

[kt315]

pulse detector is sensitive to any metal like to ferrous. you have to find too clear place at first.
you have to shield the housing inside like you do that for coil too, the foil you have to connect to (-E) of battery.

[Qiaozhi]

I think when i go outside from home with surf pi it is not stable,every time when i swing with coil make sound at every end of swing

If there is a beep at the end of every swing, then the Earth Field is not being eliminated correctly. You can confirm this by waving a whiteboard magnet (or similar) in front of the coil about 3 to 6 inches away. If it beeps during the test, then re-check your component values. This would be easier to debug if you have an oscilloscope.

[seadoggy]

If there is a beep at the end of every swing, then the Earth Field is not being eliminated correctly. You can confirm this by waving a whiteboard magnet (or similar) in front of the coil about 3 to 6 inches away. If it beeps during the test, then re-check your component values. This would be easier to debug if you have an oscilloscope.

Can i use any small magnet??,i dont have scope mate!!,i try many different coil but still problem is remain!my coil is 0.350 mh(about 23 turns wire 0.50),i have 2 board of surf pi same problem!cant search with surf pi cuz it is unstable at field

[Qiaozhi]

Can i use any small magnet??,i dont have scope mate!!,i try many different coil but still problem is remain!my coil is 0.350 mh(about 23 turns wire 0.50),i have 2 board of surf pi same problem!cant search with surf pi cuz it is unstable at field

Any small magnet should be ok for the test.

[seadoggy]

Any small magnet should be ok for the test.

I try with small magnet but when i remove magnet i lose all metal and coil dont detect any metal

[Qiaozhi]

I try with small magnet but when i remove magnet i lose all metal and coil dont detect any metal

I suggest you re-read post #1045, as you appear to have completely misunderstood the Earth Field Elimination test.

[andrewl]

Why does the oscillator input of the 7660 need to be driven by the 555? Why isn't the internal 10khz oscillator described in the data sheet (Intersil) enough?

The oscillators also seem to have different roles. Isn't the 555's 615hz to drive the logic and coil block while 10khz is to trigger 7660's pump and transfer cycles?