Surf PI Pro

[bernte_one]

thanks samii

[Davor]

Any new development here?

[terhaka]

hello guys i was trying to stimulate the circuit using multisim but I am facing a with CD4093B it is not working at the resistors values came in the original schame any help ?
an excuse my poor english

[terhaka]

hello guys i was trying to stimulate the circuit using multisim but I am facing a problem with CD4093B it is not working at the resistors values came in the original schame any help ?
an excuse my poor english

[terhaka]

hello guys l realy need help a bout CD4093 and I also asking about replacing NE5534 by TL071 please help

[porkluvr]

I can't help you with Multisim and the CD4093, sorry.

You can certainly use TL071 or LF351 but those are not really good substitutes for the NE5534. You will have greater noise and you would also need to modify the offset null components and connection.

If you can't find NE5534 (really??) then OP37 would probably be much better than TL071. The offset connections are similar to NE5534 but different component values are called for.

NE5534 is all over the place and they're good. You're just not looking in the right places.

[bernte_one]

hello

is there anybody who finished this project?

i will start this night
i want to know if unit works right.

hope that i´m not alone.

regards

[bernte_one]

my start

hello

im ready for this day 21:49 in germany, time to brush my teeth



until the next days

regards

[cristi71]

good job, but i understand how its diference beetwen this and surf pi? one more lm 358? were is this in pcb? i dont understand....regards,Cristi.

[terhaka]

I can't help you with Multisim and the CD4093, sorry.

You can certainly use TL071 or LF351 but those are not really good substitutes for the NE5534. You will have greater noise and you would also need to modify the offset null components and connection.

If you can't find NE5534 (really??) then OP37 would probably be much better than TL071. The offset connections are similar to NE5534 but different component values are called for.

NE5534 is all over the place and they're good. You're just not looking in the right places.

hi porkluvr
thanks for the help
actually I am about to build the circuit. I bought the components that I can find in my country which TL071 is one of them but I want to know how far it is not good
and how I can reduce its noise to minimum
I really appreciate your help
terhaka

[Jeroi]

hello

im ready for this day 21:49 in germany, time to brush my teeth

until the next days

regards

How is going? I am about to build this circuit as a substitute for our lame bfo circuit. Does it work for you?

[porkluvr]

hi porkluvr
thanks for the help
actually I am about to build the circuit. I bought the components that I can find in my country which TL071 is one of them but I want to know how far it is not good
and how I can reduce its noise to minimum
I really appreciate your help
terhaka

I think your PI coil for the most part, qualifies as a low impedance transducer. You generally should use a bipolar transistor input opamp to match a low impedance coil.

If you can't find a NE5534, I really don't know how to help you reduce noise with an FET amplifier like TL071. It's like you're saying "Hey, I have to shoot myself in the foot. How can I keep from feeling so much pain?"

Simple! (Don't shoot yourself in the foot.) I suppose that sounds condescending but I can't change the laws of physics.

Your detector will still work but you will probably loose a few inches depth on some materials.

Your main problem will be that if you are using an existing PCB pattern, you need to adapt the TL071 null pins to the pads laid out for the NE5534 nulling scheme. Download the two datasheets and compare the two null schemes. Hopefully you have enough room on your PCB to make the necessary changes.

Look here

[bernte_one]

Hello Jeroi,

i just wait for some components and hope that i can finish the pcb at weekend.
If i have any news i will give info here.

regards

[TH Jim]

Hi Bernte one

I am happy to see you are using my Surf PI Pro board, I'm glad someone else is getting some use from my work

I've never had any trouble with my own board, worked first time, still working well, still good depth etc. Hope you have the same!

@Cristi71

The standard Surf PI and the Pro are essentially the same except for some changes in gain around the lm358 section. I've found this usefull when working in noisey environments near power lines and RF transmitters.

Regards, Jim

[terhaka]

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