Лабораторная 10.3 — Checklist безопасности RF-измерений

Цель

Сформировать практический checklist безопасного подключения SDR-плат, приёмников, кабелей, аттенюаторов и простых электронных цепей.

Что выполняется

В работе студент:

1. описывает схему подключения;
2. проверяет наличие внешнего аттенюатора;
3. фиксирует TX/RX gain settings;
4. проверяет частотный план;
5. описывает признаки перегрузки и безопасный порядок включения.

Результат

После выполнения работы должны быть получены:

• connection diagram;
• safety checklist;
• таблица настроек;
• вывод о безопасности стенда.

Подробная техническая часть

Lab 10.3 — RF Measurement Safety Checklist

Goal

Create a practical safety checklist for connecting SDR boards, receivers, attenuators, cables and simple electronics during RF experiments.

Engineering question

What must be checked before connecting a transmitter, receiver and measurement chain?

Safety checklist

Check	Why it matters
External attenuation installed	protects receiver input
TX gain starts low	avoids overload and damage
RX gain is manual	improves reproducibility
Frequency plan documented	avoids transmitting/receiving in wrong band
Cable and connectors inspected	avoids intermittent measurements
50-ohm assumptions checked	avoids incorrect level interpretation
DC path considered	protects RF inputs from unwanted DC
Spectrum monitored first	detects overload and spurs

First-connection procedure

1. Turn TX off.
2. Insert attenuator.
3. Set TX gain to minimum.
4. Set RX gain to low/manual.
5. Confirm frequency plan.
6. Enable RX and observe noise floor.
7. Enable TX at low level.
8. Increase level only if spectrum remains clean.
9. Record metadata and measurement conditions.

Overload symptoms

Symptom	Possible cause
Flat spectral top	ADC or RF overload
Many harmonics	nonlinear stage or clipping
Noise floor rises with signal	gain compression or AGC
Signal level stops changing	saturation
Receiver becomes unstable	excessive input or poor grounding

Report checklist

• [ ] Draw connection diagram.
• [ ] State attenuation value.
• [ ] State TX/RX gain.
• [ ] State frequency plan.
• [ ] State load/cable assumptions.
• [ ] Include spectrum screenshot or generated FFT.
• [ ] Conclude whether the setup was safe and reproducible.

Engineering conclusion template

The measurement chain used ____ dB external attenuation and TX/RX gain settings ____.
No overload / overload was observed. The setup is safe / unsafe for further experiments because ______.