Practical takeaway
Receivers, transceivers, amplifiers, transverters, sensitivity, selectivity, mixers, oscillators, PTT, VFO, and modulation.
T7A · 11 pool questions
Radio Building Blocks & Station Equipment
Receivers, transceivers, amplifiers, transverters, sensitivity, selectivity, mixers, oscillators, PTT, VFO, and modulation.
Technician exam focus
This group contains 11 questions in the current pool. The teaching below keeps the important tested terms visible while explaining what they mean in normal Amateur Radio use.
1. Sensitivity and selectivity are different
Receiver sensitivity is the ability to detect a weak signal. Selectivity is the ability to discriminate between the desired signal and other signals on nearby frequencies. A receiver can be sensitive but still perform poorly in a crowded band if its selectivity is poor.
2. A transceiver does both jobs
A transceiver combines a transmitter and receiver. An RF power amplifier is added after the transmitter when more RF output power is required. An RF preamplifier increases a weak received signal before later receiver stages.
3. Mixers and oscillators make tuning possible
A mixer converts a signal from one frequency to another by combining signals and producing sum/difference products. An oscillator generates a signal at a specific frequency. The VFO sets the receive and transmit frequency as you tune the radio.
4. PTT, modulation, and transverters
The PTT input switches the transceiver from receive to transmit when activated. Modulation is the process of combining information such as speech with an RF carrier. A transverter converts a transceiver’s RF input/output to another band.
5. Mode switches on amplifiers configure the amplifier
On some VHF power amplifiers, the SSB versus CW-FM switch sets the amplifier for proper operation in the selected mode; it does not change the transmitted signal into that mode.
T7A checklist
- Sensitivity = detect weak signals.
- Selectivity = separate the desired signal from nearby signals.
- Transceiver = transmitter + receiver.
- Mixer = frequency conversion; oscillator = generates a frequency.
- PTT switches receive to transmit.
- Modulation puts information on a carrier.
- Transverter moves a transceiver to another band.
- The SSB/CW-FM amplifier switch sets the amplifier for proper operation in the selected mode.
Exam scope: NCVEC 2026–2030 Technician Class (Element 2), effective July 1, 2026 through June 30, 2030, with February 19, 2026 errata. The current NCVEC pool is the exam authority; explanatory prose here is SPARKA teaching material. NCVEC pool