One question. One answer. Zero noise.
With 6 kHz peak deviation and 2 kHz highest modulating frequency, the modulation index is 6/2 = 3.
Class C amplification is appropriate for FM because FM is a constant-envelope mode; the information is carried by frequency changes rather than amplitude variations.
In standard U.S. 120-volt branch wiring, black insulation identifies the energized or “hot” conductor.
A RACES station may use any amateur-service frequency authorized to its control operator.
An antenna tuner presents a better impedance match to the transmitter, increasing the transfer of transmitter power into the feed line.
Impedance is the total opposition a circuit presents to alternating current, including resistance and frequency-dependent effects.
At series resonance, large circulating current can develop. The voltage across the inductor or capacitor can therefore exceed the voltage applied to the entire RLC circuit.
Automatic level control keeps the exciter from driving an RF power amplifier too hard.
The gain-bandwidth frequency is the unity-gain point of the op-amp's open-loop response.
A gateway connects amateur radio users or systems to another network, including the internet.
Amateur propagation-reporting networks commonly collect reception reports from digital modes and CW to show where signals are being heard.
The official G7C11 source identifies modulation as a function that can be performed in software in an SDR.
An oscillator generates a repeating electrical signal at a defined frequency. Oscillators provide local signals for tuning, mixing, and modulation circuits.
Using maximum deviation divided by highest modulating frequency gives 7.5/3.5, approximately 2.14.
A balanced modulator produces both sidebands. A filter selects the desired sideband and rejects the other to create an SSB signal.
On 160 meters, ionospheric and atmospheric absorption are lowest along paths in darkness, making all-dark paths the best choice for long-distance propagation.
A 5/8-wave vertical reshapes the radiation pattern to place more energy near the horizon than a simple quarter-wave vertical, producing useful gain for terrestrial mobile work.
The Extra pool identifies 3 kHz as an acceptable bandwidth for HF digital voice or slow-scan television.
A sine-wave oscillator requires gain plus frequency-selective feedback. The filter establishes the frequency while the amplifier supplies the gain needed to sustain oscillation.
Hearing a repeater’s output does not guarantee that your radio is transmitting the correct access information. A wrong offset, CTCSS tone, or DCS code can all keep the repeater from responding.
An automatic notch filter looks for steady narrow carriers. A CW signal can resemble the interference it is designed to remove, so the desired CW may also be notched out.
Before a new digital protocol is used on the air, its technical characteristics must be publicly documented.
The gamma rod introduces inductive reactance, and the series capacitor is adjusted to cancel it.
Language considered indecent or obscene is prohibited in amateur transmissions.