2/14/2007
Page - 9
Connection of jumper from U4-3(output) to U1-3 required for missing 5V buss PCB trace.
There was a mistake made when the board was laid out and the connection shown below was missed. The kit
builder needs to solder a jumper in place as shown. A solid insulated wire, 26 or 28 ga, should be used for the
connection. Solder the jumper in place after U1 and U4 are soldered.
Smoke Test:
Connect the positive lead of a 12V power source to the hole marked “+V”. Connect the negative lead to the hole marked “GND”.
You can tack these to the bottom of the board, so they are easy to remove during further assembly. Apply power to the board.
Using a voltmeter, verify there is about 5 volts between pins 4 (ground) and pin 8 (+V) on U3. If this tests good, remove power
and insert U3, the ATTINY11 keyer chip and U1, the 4556 op amp. Insert a pair of headphones into the phones jack and a
paddle or straight key into the paddle jack. Restore power to the board. Using the paddle or straight key, you should hear the
side tone in the headphones. (You may find it easier to use the final power leads rather than tack in test leads.)
Содержание DC40A
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