Version: 13. Sepe
,m
er 2004
36
Cut a 15 cm piece of 0.2 mm wire (AWG 32)
and feed it through the pig nose as shown in
the drawing.
One turn is completed from one pass through
each hole.
Put on three turns: left to right through the
upper hole, then back right to left through
the lower. Once more. Done. Leave 2 cm wire
at the beginning of the wire. Don‘t pull too hard on the wire, not to dama-
ge the lacquer.
If you have done right till now, two wire ends are hanging out of the left
side of the core, on top a short, at the bottom a longer.
(I hope you don‘t get mad at my
being so detailed, describing twice
and thrice. The transformers count for
quite a number of mistakes!) Now
repeat to put on more turns.
Now do the same from the other side
for the secondary, with a 10 cm piece
of wire, leaving 3 turns primary and
three turns secondary.
Now take the first wire
again and put on ano-
ther three turns for a
total of 6 on the prima-
ry. That is 6 turns on
the left and 3 on the
right. This way the
secondary is symmetri-
cal.
Now mount the transformer, respecting its orientation by looking at the
number at the leads in the drawings. Solder the ends before mounting, to
remove the lacquer.
It is easier if the wires are long enough for them to be held firmly to the pc
board during soldering.
[ ] Tr3
QRP double hole core
G/H4
Repeat this for transformer Tr4, but remember that Tr4 has a
primary of 4 turns and a secondary of 2 turns.
[ ] Tr4
QRP double hole core
H3
Winding Instruction TR5
Now Tr5. This isn‘t much more difficult, but the 0.5 mm wire (AWG 24) is
stiffer. The holes in the BD202-43 pig nose
core are bigger, though.
Please be careful not to scrape the lacquer
on the wire on the core!!! Tr5 has a primary
of 2 x 2 turns and a secondary of 5 turns.
Cut a 25 cm piece of the 0.5 mm lacquered
copper wire (AWG 24). Begin upper left and
put on 5 turns. This means from left to right upper, then right to left lower
equals one turn. Repeat this for every turn till you have 5. The winding is
done. Naturally you have to space the turns less than in the drawing! Be
careful not to damage the lacquer on the wire.
Now follows the first part of the primary. Take
a 15 cm piece of wire and begin opposite to
the secondary, going right to left at the top,
continuing left to right at the bottom. One
turn. Now repeat this. Now the trick: twist a
30 mm loop back to the pig nose. This should
look as in the drawing. Now continue with the
free end right to left on top, left to right at
the bottom. For two full turns.
