Everything else:
[ ] U3 – 7809 Bend the leads so that the U3 hole
lines up with the board hole. Secure with 4-40 screw
and nut.
[ ] J5, J6 – 5 pins SIP socket. Make sure these are
set square and straight to the board before soldering
more then one pin.
[ ] U1, U2 - 8 pin DIP socket. Note orientation of
notch on socket and match with notch on part board
outline. Make sure all the pins are sticking out the
solder pads before soldering any!
[ ] J3, J4 – 3.5mm phone jacks
[ ] Q1, Q2, Q5 – BS170 MOSFET Note orientation
of the flat side of part. Make sure it matches the
board outline.
[ ] Q7 – 2N3904 NPN Make sure it matches the board outline.
Note: LED's may have clear lenses. Determine which color by touching to a coin battery or similar
battery. If when completed you find the intensity is too great, change R16 to 10K or 22K.
[ ] D5 - Green LED – short lead goes into hole on flat side of part outline.
[ ] D6 – Red LED – short lead goes into hole on flat side of part outline.
[ ] V1, V2 – 2K trimmer pots
[ ] Relay – not specifically labeled, but should be obvious where it goes!
[ ] J2 – DC power Jack.
[ ] J1 – BNC antenna jack
[ ] BAL – 2 pin SIP header
[ ] BALANCE – not used. It was found this part is not necessary.
[ ] Q3, Q4, Q6 – These parts require some heat sinking. Therefore, these parts get mounted with the
flat side of the package pressed against the large, tinned pad to the left of the board. A stiff piece of
paperclip wire can be used to hold the parts down against the pad by soldering it to the two mounting
holes on either side. A better method would be to use a piece of aluminum, secured with 4-40 screws,
using the mounting holes on either side. If you have some conductive paste, use it.
Flat side down
Piece of paperclip wire
Opt. aluminum w/hardware
Page 5 of 13
digital_txcvr_assembly_030720.pdf
