Barracuda Legend Kit Problems

[ionut_mtb]

Hey guys! Got one problem with the kit, i have only multimetter. i assembled board until step 7, +5v -5v ok, my voltage at U7 pin1 is +1.19 ( this is the minimum i can adjust from trimmer R14) and when i aproach metal near coil is increasing to max +4.5. In the step7 says that i shoud have voltage at U7 pin1 -2.1V. The coil is only for testing 23turns 190mm diameter of 7strand pvc cable 0,12mm. This is what i have... also i get the tone if i connect speaker to u4 pin4 and 0v, and tone if i put the coil near a pear of headphones.

[Tim]

When I got the "mono" working, it was by jerry rigging wires to only pin 1 earth and pin 4. Reversing AV plug wires didn't solve the problem, because the coil sold to me as a mono is in fact a DD! Pins 1&5 earth, pin 2 Rx, pins 3&4 Tx. So now I have an 11", and 10x5 DDs for my Surfpro. On the Bara it will work down one side with pin2 disconnected very well...but I want an 11" mono.....caveat emptor..

[Tim]

I made a Tuggle style spiderweb coil - .5mm 6 inch, but didn't make the slots deep enough, so was only able to wind 285uH worth of wire on it. But it works really well on the Bara. About 3 inches on my 1.7g flour gold. The Coiltek was sensing as metal left the field. I went back perusing the IDX thread and saw the post about a double signal being remedied by changing coil wires around, so I just tried this on the Coiltek-ML pinout GND to pos on Bara- and bugger-me-dead, it works! Now have 4 inches on 1.7g flour gold, on an 11 inch coil- and I haven't even re-zeroed the offset yet.
So I presume any ML mono will work on the Bara, as long as the plug is reversed.......

[Tim]

That's great to know Don- I may take you up on that in the future.
I need to do a search to find a more comprehensive description regarding heating and sealing the sheet plastic.
I got my ML/Coiltek 11"mono the other day, but at 285uH, it is way off for the Bara, but super-good for the Surfpro, so not a total loss.
I have ordered 20m of 22awg tinned copper wire-unsure if it will be suitable for a fast coil, but time will tell.

Any thoughts on the best homebuild PI for small gold in mineralised ground??
Also is there any way to fit VSAT to a Surfpro? I know this info is probably here via s search, but just throwing it out there.

[dfbowers]

if you can cut wood plates the it is only a smal step to vacuum forming coil shells

https://sites.google.com/site/dbcoilshells/home/resources/diy-vacuum-tables

this guy is also here in forum

I can provide them already made if you want. The clam style shells are great for anything like basket weaves or spiral wound coils.
I have them in 8", 9" and 10.5" now, up to 1" thick.
[email protected].
Don..

[Tim]

Thanks George, just had a gander at that...Ahhh! that's why I have missed so many bargains. I was thinking ebay was rigged- well it sort of is, with that.
I have ITMD now also. This will hopefully edumacate me in the use of my recently purchased Hantek 6022be scope.

Koala, I'm a up to page 50 in the IDX thread. Do your refer to the opa627? I'll keep an eye out for other substitutions. Perusing the different Classic/IDX boards/schems does show many evolutions. I have the Whites coil chart, but it is by no means comprehensive. Yes, Classic I is the 6DB coil.
I will be doing the 2-tone board, but find a display worthless on these types. However for a discriminating IB it will be essential, and I will attempt a 10 red/10 green LED using 2 LM3914s when I do an Arado or the likes.

I will be using my own parts, as I have accumulated multiples and types-every week sees another 3-5 lots coming in the mail. Components from HK/Singapore/China/Taiwan are reasonably prompt and reliable to Oz. Jaycar here are super-fast, and there are several reasonably priced suppliers in Oz/SA selling on ebay, and arriving within 2 days.
I have Mouser and Element14 accounts, but they are rarely used.

Thanks Chaps.

Out of interest, which buildable detector would you suggest for small gold, on our super-mineralised ground here in Oz?

[Koala]

Koala is your IDX a home build?
I have a Silverdog board coming, a 6x4 BlueMax, plus an IDXpro box,display and topshaft with Mr Bill mods-got it cheap because apparently it has sens issues. Fingers crossed it's settings, or was tested with an incorrect coil.
Got up at 4.30 am to catch a FalconMD20 on Ebay- my computer clock was out, and I missed the auction end by 1 second-Bugger! I'll have to make one now....

While reading reviews, etc. on the Falcon, I saw a tip about knobs getting bumped- you put an o-ring under the knob to make turning it harder.

Yes IDX is home built on Silverdogs PCB. 8" concentric is roughly the same depth as a Deus with 9" as long as you use very little discrimination and prepared to dig some deep iron. Its forte is an quite field where its hard to beat. Takes quite a few hours to learn the tones. High quality beadphone are a must. A deep coin give a quiet well rounded sound. Excellent project. If you are ordering your own components read through IDX thread as one substitution gains some depth, sorry can't remember which it is but its buried in the thread.

Be careful if you buy another coil not all 6.59 kHz are compatible. The Classic I are not. I believe all bluesmax ones are but don't take my word for it. KT posted White compatibility chart on here.


I have also built a Bandido which I think has a slight edge in normal conditions here in the UK. Discrimination is slightly better and I prefer the tone.

[Qiaozhi]

Got up at 4.30 am to catch a FalconMD20 on Ebay- my computer clock was out, and I missed the auction end by 1 second-Bugger! I'll have to make one now....

I can highly recommend using this site -> http://www.auctionsniper.com/
Then you don't have to keep monitoring eBay, or get up at stupid-o'clock to catch that wonderful bargain.

[Tim]

While I was fault-finding mine, I chopped the 9640 for the TIP127. The problem ended up being an inverted 2222, but I didn't want to mangle the board any more de-soldering the TIP. If I have a similar situation in future I would cut the legs about 2-3 mm above the board, and re-solder the pre-cut replacement fet. This way multiple change-outs would be possible without snotting the board.

I find the different tone is only discernible with the headphones. Perhaps this difference would be more noticeable with a slightly lower rated TIP?

Koala is your IDX a home build?
I have a Silverdog board coming, a 6x4 BlueMax, plus an IDXpro box,display and topshaft with Mr Bill mods-got it cheap because apparently it has sens issues. Fingers crossed it's settings, or was tested with an incorrect coil.
Got up at 4.30 am to catch a FalconMD20 on Ebay- my computer clock was out, and I missed the auction end by 1 second-Bugger! I'll have to make one now....

While reading reviews, etc. on the Falcon, I saw a tip about knobs getting bumped- you put an o-ring under the knob to make turning it harder.

[6666]

What type of coil are you calling a Tuggle style

The old spider coil, have not heard his name before

I suppose you could say it's a combination of less pronounced in the middle and sharper at the ends.

I can easily hear the difference between good targets and some iron using the TIP. Its kinda like a little wobble.

However adjusting the delay to optimum setting you loose this ability

This is interesting I wonder what characteristics the TIP brings to the circuit to create this effect, and the delay setting can upset the tone difference.
I'm tempted to chop out my Pfet and try a TIP.

[Koala]

What type of coil are you calling a Tuggle style, have you or can you record the audio that has the different sounds useing the tip127 , it would be interesting to hear thanks.

I can easily hear the difference between good targets and some iron using the TIP. Its kinda like a little wobble. Long thin iron is more noticeable as a sweep along its length gives a double beep. This is using a standard coil made out of .5 enamelled copper. I am not 100% sure but suspect its more pronounce with a smallish coil.(or was that just the way it was set up)

However adjusting the delay to optimum setting you loose this ability. I did not use the external delay fine adjust. I suspect you can use in optimum setting find a target adjust the delay to test if its iron.


The reason I didn't add the fine adjust to the delay is I sometimes detect the beach at night. Its very easy to forget to adjust something back and not being able to see carry on detecting at a none optimum setting for quite some time. I know from experience after detecting for an hour with discrimination fully up with my IDX after accidentally knocking it in the dark. Thought the beach was very quite. Ha Ha.

[Tim]

This one 6666.

I don't know if you would hear the difference on any recording. I suppose you could say it's a combination of less pronounced in the middle and sharper at the ends.

Good info bernte, I read it a long time ago, and must revisit it.

[6666]

Looks good ripsdevala. A very professional job.
Thanks Koala, good to know.
My early plywood coils I set the windings with PVA glue. It worked ok, but took a while to dry, and you will make no sense of the detector while it's wet.
My melamine plate for a Tuggle coil split in half the first time I put the hacksaw to it. Next I will try with pvc-should work.
Also going to try a spiderweb coil former made of stiff cardboard......
Another thought is a Tuggle style from 12mm ply, with a groove cut around, then slotted, with wire interwoven on 1 face 5.5mm(6mm less 1/2 hacksaw blade width).

Down the river with the dogs this arvo. Found 3 bits of lead with the Bara amongst the bottle caps. Yep, there's a definite tone difference. Coiltek 11"mono should be here tomorrow.

What type of coil are you calling a Tuggle style, have you or can you record the audio that has the different sounds useing the tip127 , it would be interesting to hear thanks.

[ripsdevala]

if you can cut wood plates the it is only a smal step to vacuum forming coil shells

https://sites.google.com/site/dbcoilshells/home/resources/diy-vacuum-tables

this guy is also here in forum

Ya that would be easy, but need to buy a vacuum cleaner and the oven first, and what kind of plastic do they use

[ripsdevala]

How about hot glue? Put some hot glue and heat it with hot gun, that what i will do next.