baracuda project questions

[satdaveuk]

Hi satdaveuk.
You're probably already bought 7660 (max 10V), that will probably work. Maybe it's better if you bought 7660A... (max 13V), it is better to leave some reserves.
Is the original 7660? It is not known with certainty, tags are deleted, but it is not so important (except for the power supply).
It is important that what is said Alexismex: Q1=TIP127 and coil L=453uH R=1R5 (fast coil - similar coils Chemelec)
Otherwise, there are substitutes for 7660:
-3 times more expensive LT1054 (max 15V)
-2 times more expensive ICL7662 (max 20V)...

Hi Maiki
You are correct have a few 7660 in stock because there used on the Minipulse3, Q1 using TIP127 old stock from the original radio spares so no problem there but wondering did it have a heat sink? , still need to make the coil.
The only thing that ive strayed from original Barrcuda is 6,800mfd capacitor ive used 4,700mfd because of size, but if i feel the need will order one up, its just im trying to use old stock.
All R/C components were checked before installing so apart from a couple of things to keep a eye on should be a result.
Been following Alexismex layout files with a fine tooth pic, You mention fast coil, by any chance do you know what wire and coil configuration was used in the original 8" Barracuda, its wound on a 7" form but was it laminated sold copper, tin plated copper wire as coiltek did and still do, Litz wire, if so how many strands, be nice if I could make original, to be honest I dont know if it was jumble wound or anything.
A fast very simple fast coil would be the famous spiderweb coil, but would rather stick to original if possible.
Many thanks

[maikl]

Hi satdaveuk.
I have no information on the wire and coil configuration was used in the original 8" Barracuda.
But the image and the information which is given Alexismex: "coil external measure= 300 mm...........internal 228mm" http://www.geotech1.com/forums/showt...t=17396&page=7 see that this is not classic PI coil, no matter what coil (heavy) for diving and the sea to be drowned in the water.
You saw that those who were working coil for (dual field) TDI or Goldscan , was essential "configuration" coil for audio response.
sinclairuser probably did not have a problem with the purity of gold, he had a problem with the size (dimensions), certainly tried a chain or earring (bernte_one gave him a good suggestion for the coil)...

[sinclairuser]

i used nine volts and it worked fine though now it only produces a continuous tone that does alter in pitch by adjusting the delay pot so as of now its non working again so when i get home on wednesday i'm going to strip it down and try again!
thanks ally x

[sinclairuser]

hi all got one of these now Farnell 20Mhz Oscilloscope DT12-5
are they any good?
thanks ally x

[satdaveuk]

20MHZ dual trace, if it works , ideal for what we are doing on here, how much did you get it for?

[satdaveuk]

Hi
Heres the form Ive made for original Barracuda 8" coil out of styreen, 7.5" inner dia/8" outer which gives .25" to play with all round for coil wire.
Still desiding what coil wire to use but its a start, space thats there proberly will be either solid copper coated with teflon or maybe 7 strand litz wire.
If I use cat5e/6 which has been quite sucessful would need to reduce centre plate, which shall do at some point as experiment but at the moment trying to reproduce the original near as possible.

[satdaveuk]

What ive desided to do is add or cut out another inner form to make it a shade thicker then I can use .45 insulated copper tinned 7 strand alarm wire without changing coil dia spec.
At the moment with 25 turns 1m getting 389uh at 1.1 ohms so with another 5 or so turns should bring me to the Barracuda spec, far as capacitance shall cross that bridge later.

[sinclairuser]

20MHZ dual trace, if it works , ideal for what we are doing on here, how much did you get it for?

just the petrol for my mate to deliver it (owed me a favor and a 2mtr/70cm mobile!) it seems ok i have a manual with it so it will do for me!

[peterr88]

Can anyone tell me was the original Barracuda designed to work on 9v or 12v please ?

[satdaveuk]

Hi Peter
Maiki answered that question further up the page, It was run on 8 rechargeable cells at 1.2v each which equals 9.6V