Surf PI - successful build

[chrisw]

Yes the boxes look really good quality, but as you say a little on the expensive side especially for the black. But as they say; you get what you pay for.

[Qiaozhi]

Thanks for that George.

As you can see, these enclosures are high quality anodised (and not cheap). All the holes were CNC punched, and the panels were laser printed. It will be a very very long time before any of the text wears off. There was also a carrier plate to support the battery pack and the internal speaker. The only problem is that they're not waterproof.

[chrisw]

Thanks for that George.

[Qiaozhi]

Anyone know where the original crossbow enclosure was from and what size it was?

Chris

It came from here ->

http://www.lincolnbinns.com/uniobox-2/

[chrisw]

Anyone know where the original crossbow enclosure was from and what size it was?

Chris

[SVEN1]

Out hunting in the city areas EMI tends to rise by 10am, when the world comes alive. And settles back down after 6pm when folks get back home from work.
So if out hunting, might have to make avery very slight frequency adjust now and then. Not so much at the beach. Had one city beach up north, get within a certain area
and the EMi became nasty, couldn't run any VLF machine there using more than 50% (gain, sensitivity) resulting in loss of depth. My PI was bothered but, sould still hunt.
It was like a 50' wide area, like some one sent out a EMI beam . You knew when you were getting close and exiting this zone. Smaller coil helped in this area over the larger coil.
I have hunted places that never needed a frequency adjustment and the threshold purred very slowly without a hic-cup.

[chrisw]

Hi 6666,
Yes Sven has got it right. Its not as bad now as it was when I first built it, but still occasionally the emi causes a need to adjust the frequency to make it quieter. But once the detector is settled it works very well. Then a little later its as if it wakes up and starts to make noise again, so another adjustment is required. Since most of my life I have used VLF machines, I am not used to having to make any adjustments. But to be fair I haven't tried my detector away from home, such as on the beach. In my area I think there must be a lot of emi noise.

[SVEN1]

I may have mixed up Chris W in the UK with Chris W in Oz.

[6666]

He has problems with EMI in the home so he can't find a stable frequency to keep the threshold a contant tick. He is using one of the new version boards where we
changed from a trimpot and with an external frequency control to a fixed PCB resistor and with an external control. The external frequency control only needs to be adjusted a very tiny amount at a time.
can be an issue for some. I am going to try a multi-turn control pot for the external freq. control.

Hi, ok so its a EMI problem, is the pcb inside a metal box ?

[SVEN1]

Chris can you please explain why you need constant frequency adjustments ? what does your machine do to require it ?

He has problems with EMI in the home so he can't find a stable frequency to keep the threshold a contant tick. He is using one of the new version boards where we
changed from a trimpot and with an external frequency control to a fixed PCB resistor and with an external control. The external frequency control only needs to be adjusted a very tiny amount at a time.
can be an issue for some. I am going to try a multi-turn control pot for the external freq. control.

[6666]

Hi Bernte_one,
My Mirage seems ok but I cant quite make the 30 cm mark yet, but I am still experimenting with coils. Also it is very sensitive an needs regular frequency adjustment. So I will have a go at the crossbow.

Chris

Chris can you please explain why you need constant frequency adjustments ? what does your machine do to require it ?

[multieagle]

Building the Crossbow will not be an easy task, and I certainly wouldn't recommend anyone to even try it if their electronics knowledge is weak, or they don't have an oscilloscope and understand how to use it.

Thank you. Being a novice, this may be beyond my skills. However, will attempt one of two boards . . . VERY SLOWLY following in other footsteps.

[chrisw]

Yeah she's chinese, came from China to Uk 8 years ago.

[Qiaozhi]

Thats interesting I often wondered what it meant, I just asked my wife what your avatar said, she confirmed it said George.

克里斯 (Chris)

I guess she's either Chinese and/or understands Mandarin?

[chrisw]

Thats interesting I often wondered what it meant, I just asked my wife what your avatar said, she confirmed it said George.

克里斯 (Chris)