BARACUDA-Legend-1

[Toros]

Try post #616

Thank you 6666!

[satdaveuk]

real tests

Hi
On holiday at the moment in cornwall testing out the Barracuda what a result so impressed , will tell you all about it when i get back lads

The 6,800mfd is diffecult to find unless willing to pay good money I managed to get 8,200 with the right phisical size , better to go up than down although my first build is running on 4,700 with marvelous results.
Mysecond build is on the work bench all resistors and caps installed .
Talk later
Regards

[6666]

On holiday at the moment in cornwall testing out the Barracuda what a result so impressed

Dave We will be waiting for your words of wisdom.

[liekwang]

?Hi all I want to ask anyone who has tried to assemble the baracuda is there a false signal if the coil in ayun_ayun, so I made a pro surf there is always false if the signal coil swinging a stick at

[mohandes]

HI all
do anyone know different between , MPS102 and BF256?
tanks

[mohandes]

all gurus hi
tonight i finish my old baracuda detector but sound(speaker is low) and depth is very bad.
i use bf256 instead of mps102 so i think it is not ok,can i use 2n3819 insteaf of mps102 and 2n5485?any idea?i find too another fet transistor but it is not in my country.

how can i adjust it when i found best parallel resistor , please tell me?

[mohandes]

i forgot ask this :
are the pots 25k should be adjust?what the value it?

[Old cart]

How did you make those nice labels on the Baracuda?

[satdaveuk]

Hi
The small amount of time I had detecting while away in cornwall was quite impressive although the the 8" coil I intended to do most of the reasearch with had not been packed which peed me off.
Anyway what I did have with me was my small 1.5" coil which got me some old 3d pieces plus old 1 and half ds plus modern coins mainly around and in rock pools where larger coils would proberly miss.
Had also put a bundle of cat5e in a bag so wound 4 turnes of that like ive seen done on here together with a adaptor cable tied to fit the waterpipe exstension rod I use on the small coil.
Tryed it in the caravan and considering I was surounded by metal it worked really well, so down to the beach I went and it was rubbish, unstable no matter what hight the coil was kept at, just couldnt get a even threshold, it was in and out like a childs yo yo.
Anyway as a quick fix went and bought some kitchen foil to shield it and that didnt make alot of difference so gave up on it.
All in all it was a bit of a anti climax because although I proved how well the machine can operate with the small coil on wet/dry sand, im far back as china far as the larger coils that I built because dont know when I can get down there again.
One thing I have proved though yet again, a badly built coil may work wonders in air tests but once its applied to the ground surface where it belongs it can render the detector usless.
Would be handy to here from those of you who have been out detecting with these machines how you been getting on.
With the small coil its a beast, and ground conditions have little effect on it, so if all things are right the 8" coil should be the same as all made with the same material, although been a bigger coil is going to see more ground.
Regards

[maikl]

Hi satdaveuk,
what did you put the FET on Barracuda?

[doncholito]

Hello, I ask some question about building my Baracuda. Here in my country i have not find Q3 - 2N5485, can I use MPF102? (q4,5,7 i use MPF102)

[mohandes]

HI gurus
now i finish the new baracuda detector but i use 2n3819 instead of MPF102 and bf256 instead of 2n5485.
just know that i return 180 deg bf256 and i have to change the pin of 2n3819(look the datasheet please)
But speaker dont have sound when i return delay and treshold .WHY?
coil is 460 mkh and 2.1 ohm and the res is 330hm 2watt.i get the voltage of the coil and it is 0.1v ???
i have 690hz on pin8 40106 and 11.9v on collector 2n2222 and 635hz.
I check other points (votages)and are ok, why the speaker have not sound????????
thanks friend





Edit : 2n3819 is D,G,S but MPF102 is D,S,G.
bf256 is G,S,D but 2n5485 is D,S,G.
i wait for your helps.

cheers

[satdaveuk]

Hi satdaveuk,what did you put the FET on Barracuda?

Hi Maik
I don't know which fet your referring too but all components are the same as the original Barracuda hand drawn circuit and part numbers/description and made PCB from the lay files, apart from the reservoir capacitor which should be 6,200mfd which I replaced with a 4,700mfd, All resistors and capacitors were checked before installing to a tolerence of 1% or less.
Its quite a education that out of a bag of 50 good quality branded capacitors your lucky to find 6-7 that are within the spec specified.
Thanks for your feedback
Regards

[satdaveuk]

Hi Mohandles
The second build I am in the middle of making is using allot of those green capacitors you have used, I manged to buy a few hundred of those at the right price, and doing ESR checks for spec im getting about 10 out of every 50 that pull me into the 1% tolerance, which includes applying a little heat and then a quick freeze, which needs to be done because remember these detectors are getting used in various temperatures through out the year.
The main reason why I bought them to try was because they were used allot in the older transceivers back in the early 70s there placements within the circuits needed to be of accurate specification.
When they used to come in the workshops for repair it was very rare to find capacitor breakdown, was normally either fractured print or transistor breakdown due to battery terminal mix up.
Only draw back with those caps is when going for the higher capacitance they are a bit on the large side for this project as in they stand quite tall, also they were never the reliable st of capacitors in high voltage applications, but fine for what we are doing here.
All the best

[mohandes]

hi stadaveuk and gurus
sorry me my english bad but i think you say the green caps are ok!!!
but my ? are:

have good equivalent for the mpf and 2n5485?

whay the speaker dont work?

why i havenot 2.9 volts at the coil ?and another say in last post

regards