❒8. Move your meter probe over to TP2, key the transmitter and adjust L5 and L11 for maximum negative reading. Once again, go back and forth between the two coils. You should get a reading of at least
❒9. You should now be able to see RF power at the output antenna jack, J1. Adjust capacitor C12 for maximum RF power output.
❒10. Slightly spread or compress coils L3 and L4 to maximize output power. Power should be at least 4 watts with a 12 volt power source.
❒11. While speaking into the microphone, slowly rotate modulation control R13 clockwise for best sounding modulation. Ideally, a
❒12. If a frequency counter or service monitor is available, adjust capacitor C43 for exactly 146.520 MHz. If you do not have such equipment, use a receiver with a center tune meter.
This completes the alignment of your FT146. The PC board should be mounted into a protective enclosure to guard against accidental contact. The Ramsey CFT case set provides an ideal, perfectly sized and matched case for your FT146. Study the following sections regarding the DC power supply and RF power indication, and operate your transmitter in accord with good amateur radio 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 transmitter. 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
If your supply voltage is in the
VERIFYING TRANSMITTER RF OUTPUT
The most important thing to know is whether your transmitter is delivering some measurable and reassuring level of RF power to the antenna. The sound of the
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