Secondary leads (wound previously)
1 turn with loop then
another turn
Twistthe loop togethertightly (notshown tightly forclarity)
47. Locate the smaller transformer (T2) and install it snugly on the PC board.
48. Install the larger transformer (T1) into the indicated location on the PC board.
49. Install L1, a 15 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.
50. Install L2, the 16 turn toroid inductor - you marked it, remember?
51. Install L3, the remaining 15 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:
•
•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 |
|
•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!.
1. Rotate Bias pot R4 fully CCW.
2. Connect a multimeter to TP1 ; set the meter to read up to 5 volts DC.