Hi OMs
I got a schematic for an amplifier.What is:
an Unelco
a coil with 3 turns #16 enameled wire,3/16" ID (everything unclear except
the 3 turns)
dura mica

mni tnx
Tom

You actually can't wind around the coil until it's
made.

You make it by winding number 16 gauge enamelled
wire
around a former (a drill shank will do) three
times.
Leave enough at the ends to atach the coil to
whatever.
Note - the wire will be a bit springy - you may
have to
use a slightly smaller former and allow it to
expand
to 3/16".

Cheers.
Murray

Killa T wrote:

On Sat, 26 Jul 2003 22:47:18 +0200, "Tom" wrote:

Hi OMs
I got a schematic for an amplifier.What is:
an Unelco
a coil with 3 turns #16 enameled wire,3/16" ID (everything unclear except
the 3 turns)
dura mica

mni tnx
Tom


Duh, three full turns of enameled #16 wire wound around the coil! Careful you don't electrocute yourself!

Murray Kelly vk4aok

schrieb im Newsbeitrag
...
You actually can't wind around the coil until it's
made.

You make it by winding number 16 gauge enamelled
wire
around a former (a drill shank will do) three
times.
Leave enough at the ends to atach the coil to
whatever.
Note - the wire will be a bit springy - you may
have to
use a slightly smaller former and allow it to
expand
to 3/16".

Cheers.
Murray

Hi
Is 3/16" the coil length ? And what's "enamelled wire" ? Isolated wire ? My
technical english dic ain't available at the moment.

Tom

got a schematic for an amplifier.What is:
an Unelco
a coil with 3 turns #16 enameled wire,3/16" ID (everything unclear except
the 3 turns)
dura mica


I'm not sure if Unelco refers to a brand name, or if it is a type of
construction unique to a certain brand. But whenever I run into Unelco
caps, they are always these 'square pads' that have a tab on the side.
The capacitance is from the construction. The square pad is soldered
down, and the tab is insulated from the square tab, the insulation being
the diaelectric. You usually find these in high power amplifiers as
bypass on the final stages where there may be respectable RF current.

As to the coil, there's usually one other 'spec' that you seem to be
missing. That's the 'turns per inch'. But in it's absence, you can
still easily make the coil. In this case, just get a 3/16" bar and wrap
your 16ga wire around it 3 times and you have your coil. If it's not
specified, try to make the coils spaced 1 width apart. Some people
wrap TWO wires to make the coil, then unwrap one, leaving space
for a wire between the wraps.

With 16ga wire it's not easy, but if you can find a 'coarse thread bolt'
in 3/8" diameter, wrap the wire to follow the threads. Then unscrew
the bolt out of the coil. If you need wider spacing, you can gently
'pull' the thing to stretch it out. I had one kit one time that specified
the coils by what bolts to wind them on...