Surf PI Pro

[porkluvr]

thanks porkluvr for the detailed explanation and (I will take the pain ) but I have another question about the speaker how many ohms and watts I have to us for the speaker

Surf PI Pro was designed for high impedance headphones. If you want to instead use a speaker or low impedance headphones you could add a small audio transformer across the headphone terminals, such as 2k:8 ohms. The exact value is not really critical but some would work better than others.

You could also just use a 16, 32, or 64 ohm speaker to replace the 1k pot which may not be the best option but would be the simplest.

Why don't you look through other Surf PI threads. I'm sure you will get some better ideas.

[bernte_one]

caps 1uF and 220nf

hello jim

at your layout are big caps for 220nf and 1uF

there is the info some postings above that it will be better to replace the 1uf (none polarized) with a polarized is this right and which direction?

for the 22nf caps i have only mks type here 63V (the small) but layout shows bigger ones but which type are them?

thanks for your support.

regards

[TH Jim]

Hi Bernd,

Sent you a PM.

Regards, Jim.

[TH Jim]

Hi Bernd,

Photo's of my board. Sorry they are not from the best angle but it is a real pain to remove the board from the housing, but should be clear enough for you to see. I wouldn't worry about the component body types you want to use - as you can see, mine is made from whatever parts were in my junk box and it works fine!

Regards, Jim.

[wallker]

Hi Jim,
could you tell us something about sensitivity on 1 euro coin and soda can (and diameter of coil used for those testing) ?
Also if you made barracuda from Alexismex could you compare it with Surf PRO (i would appreciated your opinion).
Regards Marko.

[bernte_one]

thanks jim for the pictures

i only wait for a big 1uf mks cap to finsh my board

i think im on the right way

regards bernd

[satdaveuk]

this may be useful to some of you just check its up todate, project i never got round to its using the large board like above if you need the copper side etc just ask.
All i want is a thankyou

Regards

[bernte_one]

All i want is a thankyou

Regards

for what, is there something new on the layout picture you posted?

did i dont see what you will say?

[satdaveuk]

Dont think theres anything new its just a nice big print for those of us whos eyes are not as good as they used to be for component placment

[bernte_one]

Dont think theres anything new its just a nice big print for those of us whos eyes are not as good as they used to be for component placment

ahh ok

the difference is not in picture its in the viewer
age 66 age 30

hope you can laugh over it

nice sunny day

regards

[TH Jim]

Hi Guys,

The coil I use on the Surf PI is elecptical and roughly 8 x 6 inches, 23 turns of 0.4mm enamelled wire. Havent air tested it on a Euro coin but would expect a similar result to the gold rings in my Baracuda video on youtube.

IMHO There is not a lot of difference in the detecting capability of the Baracuda, the Surf PI or the Surf PI Pro. I prefer the Surf PI's as they are easier to work with and don't need matched FET's and they use less power.

Cheers, Jim.

[6666]

Jim do you have a link to your youtube video
that you mentioned I had a look but did not find it
thanks

[TH Jim]

Hi 6666

Here is the link

http://www.youtube.com/watch?v=jC5uNrUjP5U

Regards, Jim.

[6666]

Thanks jim
thats an impressive test what were the coil specs in that video ? thanks

[TH Jim]

G'day 6666

Thanks for your kind words

That coil was 21 turns of 0.4mm enamelled copper wire, 10 x 8 inch eliptical (9.75 inch circular). Sheilding material was conductive mylar (emergency blanket/ space blanket), cut into 1 inch wide strip and spiral wrapped around the wire bundle.

Regards, Jim.