Garrett (pulse) XL 500

[reptooyep]

Yes, that's it ... I would have saved time and few metters of wire i i've seen this thread before.
I did not have the translation the first time i did it .
I'll take care to cover the wire with tape before epoxy !!

[reptooyep]

#40
About pot IP67 I can only say, they are dust proof and in my opinion, it means not, that they are water proof.
The trimmer 10k near 78L05 is threshold for audio and 25k near 4538 is discriminate basic adjustment. 10k near T5 is low battery control, Trimmer 100k near 709 is also not critical. Near middle position, you will have the best operation point and detecting range for targets.
As I made this detector in 2004, I had only a simple multimeter and my ears for adjustment. It was very quick to do.

can't wait for my 100k resistor, i think i'll steal them from an old board ..
The first number of IP67 is for dust and the second for water. 7 correspond to immersion but i don't know if it will works few meter depth.
I was hasking myself about the LM709 100k pot, i had more trouble understanding this one than the others.
A last question ? the disc level increase when the resistance increase or is it the oposit ? It's important for the pot wiring.
Thousand thanks

[rocco_k]

hi.
is there a hex file from the pic?

[blobber]

can't wait for my 100k resistor, i think i'll steal them from an old board ..
The first number of IP67 is for dust and the second for water. 7 correspond to immersion but i don't know if it will works few meter depth.
I was hasking myself about the LM709 100k pot, i had more trouble understanding this one than the others.
A last question ? the disc level increase when the resistance increase or is it the oposit ? It's important for the pot wiring.
Thousand thanks

Aha..well, I only saw with google about IP67 pots, there where the description
only dust proof. Anyway, it should work , at least for a while.


About disc. resistance, I am not sure and I don't want to open my box,
because I'am glad, that I had sealed all water proof now and ready for
soon next holidays in spain.

[blobber]

In any case; I would suggest you, to made your housing also with pre pressured air, as I shown in my video.
So you will have at least an indicator, until all is water proof.

[reptooyep]

I plan to add a wheel valve on the box to pressurise with a bicycle pump.
I would love to tune sensitivity and disc underwater but i have only a waterproof 10k log so, it will be hard to adjust
The sensitivity. A linear one would have been the best i think.

[blobber]

Yes I also use a valve from a bicycle wheel, to pressurise the box with a bicycle pump. Under the screwable valve adapter, is my charging socket for the battery.

For the pot sealing, I use simple parts of heating valves, made of brass. I know, this is not a good choice, parts of stainless steel should be better, but the knobs are full with silicone grease, there I have no problems with corrosion.

My very cheap headphones are sealed with epoxy resin or superglue, both variants are good. Before I dive the two*pieces in the solution, I close the air transfer channel with thickened epoxy. When all is dried, I only put a very small needle through this channel, to get a very small hole for the sound. This is working fine since many years.

I use my unit while snorkeling* on the beach,* in breast deep water and only with a plastic scoop. Maybe not so effective than a scoop with long handle, but anyway I have fun.

[reptooyep]

Having fun is a must. I'm having more fun to build than to use but when i'll have 5 or 6 good working MD, it will change.
I'm working in french navy sea patrol and i can get tousand of valves in trash bin.
I think i'll hide the DISC pot in the box and the SENS pot external.
For the charging, i'll add a coil with diode bridge and regulator.Does the unit work with a simple 9v battery ?
If you put a loud toy speaker in the box, the sound travell very good in water, so, you should not need any headphone ? A phone vibrator would also do the job underwater ..

[blobber]

You have nice ideas, very interesting.
Well, I think a 9 Volt block should work, but the current consumtion is with 85 mA a bit too much. I use 8 x 1,2V NiMH 900mAh. Under 7V the MD is not working.

[blobber]

I hope, we will see soon some pictures of your finished XL500. I am very excited about your results.
Good luck!

Fred

[ripsdevala]

Fred sir, do you have partlist, im on the way to electro part depot, cant see te lay file for now, i will try to build this one

[blobber]

Hello Arief,

unfortunately I have no part list. To open the layout file, look for sprint layout 5 viewer
or a unofficially version, of this old programm.

Fred

[ripsdevala]

I just buy the resistors, IC and transistor from the schematic, will work the pcb later...

[ripsdevala]

Mr.Fred, this point is a joint with the track right?

[blobber]

Sorry no. The vertical line should be here 0,3 mm.