Ramsey Electronics QAMP40 - Manual (Page 12)

QAMP-40 • 12
ˆ 47. Locate the smaller transformer (T2) and install it snugly on the PC board.
ˆ 48. Install the larger transformer (T1) into the indicated location on the PC
board.
ˆ 49. Install L1, a 19 turn toroid inductor wound previously. If desired, a small
dab of hot melt glue, bathtub sealer, or caulk may be used to secure the
toroids.
ˆ 50. Install L2, the 22 turn toroid inductor - you marked it, remember?
ˆ 51. Install L3, the remaining 19 turn toroid inductor.
This completes the assembly of your QRP power amplifier. Now's a good time to
give your masterpiece a good going over, being especially alert for any:
•
bridged-over solder joints;
•
misplaced components;
•
transistors or diodes placed wrong;
•
electrolytic capacitors installed wrong.
INITIAL TESTS:
To prepare your amplifier for testing you'll need the following:
•
1. Multimeter capable of measuring voltage and current.
•
2. 12 volt DC power source of at least 3 amp capacity.
•
3. Suitable dummy load and resonant antenna.
•
4. QRP transmitter with a power output in the ½ to 2 watt range,
such as the Ramsey QRP-40.
•
5. Proper cables to interface between the QRP transmitter and the
QRP power amplifier.
With the above all set up and handy, let's get testing!
ˆ
1. Rotate Bias pot R4 fully CCW.
ˆ 2. Connect a multimeter to TP1 ; set the meter to read up to 5 volts DC.
Secondary leads
(wound previously)
1 turn with loop then
another turn
Twist the loop together tightly
(not shown tightly for clarity)