2/14/2007
Page - 10
Group 2: Receiver front end:
NOTES:
C8:
the flat side of the trimmer goes towards the line on the
outline.
U2:
Install the 16-pin socket at the U2 position. Be sure the
notch is positioned to match the notch shown on the board.
Then install U2 into the socket orienting the dot and notch.
T1:
Band Specific Transformer, See Page 5
Using the red wire and a red T37-2 core, wind the required number of turns for the band you
are building. Keep the turns snug and as close together as you can. This is the secondary
winding (SEC). Wind 5 turns of the green magnet wire in the space between the start and
finish of the secondary winding. This is the primary or link winding (LINK) You can overlap
these turns if there isn't enough room to make a single layer. Trim back the leads to about
1/4” and tin. Tinning can be done with a
HOT
soldering iron. It helps to have a blob of solder
on the tip when you do this. Start at the wire end and move back toward the core. Insert the
two red wire leads into the holes labeled “SEC” on the diagram and the two green wires into the holes labeled
“LINK”. The two holes on the left (closest to the edge of the board), are both ground, so it doesn't matter if the SEC
and LINK wires on this end are crossed. Trim the T1 leads after they are soldered.
location
value
markings
√
R26
10 ohms
BRN/BLK/BLK
R12
22 K
RED/RED/ORG
R28
100 K
BRN/BLK/YEL
R27
470 ohms
YEL/VIO/BRN
C3
.1 uF
104 Mono
C37
.1 uF
104 Mono
C26
.1 uF
104 Mono
C38
.001 uF
102 Mono or Disk
C39
.001 uF
102 Mono or Disk
C36
.001 uF
102 Mono or Disk
C7
Band
specific
See page 5
C8
40p
Yellow trimmer
Q10
2N3819
jfet
Q8
2N7000
U2
Socket
16-pin
Q7
2N7000
Q9
2N7000
U2
74HC4053
T3
See text
T1
Band
Specific
See page 5
Summary of Contents for DC40A
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