Version: 13. September 2004
31
[ ] C79
47nF
473
G2
[ ] C80
47nF
473
F2
[ ] R17
1,5K
E5
[ ] R18
1,5K
E5
[ ] R19
1,5K
D/E5
[ x] R20
2k7
0805 SMD
E4
[ x] R21
1k2
0805 SMD
E4
[X] R22
10R
0805 SMD
E3
[ x] R23
39R
0805 SMD
E3/4
[ ] R24
1,5K
F3
[ ] R25
1,5K
D3
[ ] R26
47R
D4
[ ] R27
2k7R
D5
[ ] R28
1k2
D5
[ ] R29
1K
D5
[X] R30
10R
0805 SMD
D5
[ ] R31
39R
D5
[ ] R32
100K
D5
[ ] R33
1K
C5
[ ] R52
1,2K
FG/2
[ ] R53
330R
FG/2
[ ] R54
depending on instrument
F2 ( wire bridge is bargraph)
[ x] R55
1K
0805 SMD
E4
[ ] P2
10K Piher PT6 lying
F2
Winding instructions Transformer TR1
Now, after a pause, follows a new part.
The transformer Tr1 is wound on a double
hole („pig nose“)
core.
Put the pig nose
core in front of
you, so that the
holes pass from left
to right. Tr1 has a primary of 4 turns, and a se-
condary of 2 turns, to transform downwards. Like
the other diagrams for transformers, this drawing also contains a dot. This
is always the beginning of the winding (for coils too). Cut a 15 cm piece of
0.2 mm wire (AWG 32), and feed it through
the pig nose, as shown in the diagram. One
turn is done by going through one hole and
back through the other. Make three turns:
Through the upper hole going right (leave
and end of some 2 cm outside). Back through
the lower hole. One turn done.
Now go on: through the upper hole, back
through the lower. End of turn two. Don‘t
scratch the wire on the edge of the core! The lacquer is easily damaged.
Go on with turn 2 and the primary is done. This completes the primary, and
leaves us to do the secondary. To easy mounting, our developer has laid out
Tr1 so that the secondary leaves the core opposite to the primary.
Take a 10 cm piece of 0.2 mm wire
(AWG 32) and feed it carefully from
right to left through the upper hole
and back from left to right through
the lower hole. End of the first se-
condary winding. Two more and we are
finished!
Now the transformer
can be mounted. The
secondary goes to 3 and
4, the primary to point
1 and 2, as shown in
the layout.
[ ] Tr1
QRP double hole core
F3/4
