3. Connect a dummy load to J1, the amplifier RF output. In a pinch, a light bulb may be used - see the section, "Verifying RF Power Output."
4. Temporarily install a jumper from the collector of Q3 to ground.
5. Apply power to the amplifier but do not turn on the transmitter. Measure the current drawn by the amplifier and slowly rotate the bias pot, R4, clockwise until you reach a reading of ¼ amp. Do not allow the current to rise above ½ amp. If you cannot adjust or reduce the current, disconnect the power supply and consult the troubleshooting hints section. The voltage at TP1 should be about 3.2 to 3.5 volts.
6. Turn off power. Disconnect jumper from Q3 to ground.
7. Connect the QRP transmitter to the input of the amplifier. Key the transmitter. You should hear the
This completes the testing of your QRP power amplifier. The PC board should be mounted into a protective enclosure to guard against accidental contact. The Ramsey CQAMP case set provides an ideal perfectly sized cabinet that matches all other Ramsey kits.
Study the following sections on DC power supply and RF power considerations. Operate your transmitter with good amateur practice.
YOUR POWER SUPPLY AND RF OUTPUT POWER
For optimum performance, one or two volts of extra DC supply power can make quite a difference in any RF power amplifier. For example, two lantern batteries in series, or 8 D cells, will obviously provide about 12 volts with sufficient current capability for casual operating. For maximum RF output power, use a supply of 13 to 14 volts DC. The easiest method is to place two fresh D cells in series with your power source if a full 13.6 - 15 volts DC is not available. Be aware that batteries are not the optimum power source, especially if you are prone to long QSOs! A word of caution concerning wall plug style AC adapter power supplies: They are not suitable for operation of your amplifier due to their poor regulation, AC ripple content, and RFI susceptibility.
With 1 watt of drive and a supply voltage in the
