MFT-40 DSB Transceiver Kit
Page 16
Resonator (or optional crystals)
Install X1resonator marked as 7200 (or 7370 optional).
Relay
Install relay RL1; it can only be mounted in one position.
Make sure that the body of the relay lies flat against the circuit board.
Shielded coils (cans)
L1, L2, L3 and L6 are shielded coils equivalent to Toko KANK3334, marked as
5u3H
. They are RF
transformers for the passband filters. Make sure that they lie flat against the circuit board.
In order to solder the tabs of the shield, you will need to hold the soldering iron a little longer on the joint
or use a higher-wattage soldering iron.
LPF Toroids L10 and L11
L10 and L11 are identical. They use T37-2 cores (red toroid with 9.5mm/0.375in OD).
Cut 25cm
(10”) of 0.5mm diameter enameled wire and wind sixteen (16) turns on a red toroidal T37-2
core. 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 10mm
(0.4”). Scrape off the enamel with a cutter
from the ends of the wire, in order to solder the toroid onto the board.
Counting the turns: Count one turn for every time the wire passes through the center of the toroid.
Important: wind the toroid exactly as shown in the pictures.
One turn more or less will affect the operation and the power output.
