DB4020 Dual Band 40&20M SSB QRP Transceiver Kit
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Install IC3, IC9 and IC8. These are regulatory integrated circuits. Be careful not to confuse IC3 (78L05)
with IC9 (7805).
IMPORTANT: Make sure that the IC's are fully inserted into their sockets. A poor contact between the
socket and IC can cause malfunction of the kit.
C
rystals
Install
X1
through
X8
.
X1, X2, X3 and X4 are part of the IF receiver filter, and X5, X6, X7 and X8 are the IF transmitter filter.
These crystals have been hand-picked (they have handwritten numbers on them) and have the same
resonant frequency, in order to obtain the best filter quality.
The crystal housing should not touch the board; place them slightly separated from the board, at a
distance of 0.5mm.
Note:
With a scrap piece of wire left, you can solder the crystals housings to GND.
R
elays
Install relays RL1 to RL8. They can only be placed in one position.
Make sure that the body of the relay lies flat against the circuit board.
S
hielded coils (cans)
L2, and L3 are shielded coils equivalent to Toko KANK3334, marked as
5u3H or 5R3
.
L4, and L5 are shielded coils equivalent to Toko KANK3335, marked as
1u2H or 1R2
.
They are RF transformers for the bandpass 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.
