EGV-9B_BPFLPF
module for EGV-9B CW Transceiver kit
Page 7
TOROIDS ASSEMBLY EXAMPLE:
T
he following example is the low pass filter for 40m
40m LPF Toroids L10, L11 and L12
L10 and L12
are identical and are wound with
18 turns
.
L11
is wound with
20 turns
.
They use T37-2 (red toroids 9.5mm/0.375in outer diameter).
Cut about 28
cm (10.3”) of 0.4mm diameter enameled wire and wind the
L10 and L11
toroids with
eighteen (18) turns. Spread the turns evenly around the toroid and wind them tightly so that they follow
the contour of the toroid and are as tight against the toroid as possible. The turns should be evenly
distributed around the circumference of the toroid.
Leave pigtails of about 10-12mm (0.70
”). Scrape off the enamel with a knife from the ends of the wire, in
order to solder the toroid onto the board.
For
L11
cut about 30cm (12
”) of 0.5mm diameter enameled wire and wind twenty (20) turns.
Mount and solder the three toroids in place.
Counting the turns: Count one turn for each pass of the wire through the center of the toroid.
Important: Wind the toroid exactly as shown in the images. One turn more or less will affect the
transmitter spectrum and the output power.
