A Simple 80 Metre DSB Minitransceiver
VK3AJG

The receiver is quite sensitive and tunes about 80-90Khz, tx output is ~300-500mW

schematic























 
schematic
schematic (eagle CAD)
pc board (eagle CAD)
pc board (pdf)

photo-1
photo-2
photo-3
photo-4

C26 is small plastic tuning capacitor (100pf)
Q4 is 3.58Mhz ceramic resonator.
Coil L1 is 10 turns trifilar wound on ferrite bead.
Coil L6 is 10 turns bifilar wound on ferrite bead.
Coil L7 is 14 turns on old 10mm 455Khz IF Can.
All other coils are RF chokes.
Tx/Rx switching is done with a DPDT switch connected to
JP3 and JP5.
Adjust preset pots for best carrier balance on tx, and tune
L7 for best reception.

NOTE:  Must use double sided pc board, with the top layer as a ground plane,
using single sided board the receiver will not work very well.


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Last Update: 07/11/09