5 km 27 MHz Sensor Transmitter and receiver
Budget: ₹37,500 – ₹75,000 INR
I am putting together a long-range monitoring system that will stream temperature and pressure readings from a remote site back to a base station. The link must operate on the 27 MHz band and hold a reliable, error-checked connection over roughly 5 km of open ground.
Transmitter with simplex transmission:
• Power: a single 3.7 V Li-ion cell.
• Payload: simple sensor packets every hour update (temperature and pressure values only; no audio/video).
• Duty cycle should be low enough to keep the battery alive for Months, yet robust enough to tolerate moderate interference.
Receiver
• Power: 220 V AC mains.
• Continuous listening with a clean digital output that I can feed directly into a microcontroller or data-logger for further processing.
What I need from you
1. Full circuit schematic (transmitter and receiver).
2. PCB layout and working model with files and complete bill of materials with readily available parts.
3. Firmware or modulation scheme documentation that shows how the sensor bytes are encoded, transmitted, and verified on reception.
4. Recommended antenna design and alignment notes to achieve the stated 5 km range.
5. Brief test procedure so I can replicate your range and reliability results before moving to production.
If you have previous experience with low-band UHF/HF data links or have already built battery-powered telemetry modules, that background will be a plus. Please keep the design lean, component counts low, and regulatory considerations for 27 MHz operation in mind.
Transmitter with simplex transmission:
• Power: a single 3.7 V Li-ion cell.
• Payload: simple sensor packets every hour update (temperature and pressure values only; no audio/video).
• Duty cycle should be low enough to keep the battery alive for Months, yet robust enough to tolerate moderate interference.
Receiver
• Power: 220 V AC mains.
• Continuous listening with a clean digital output that I can feed directly into a microcontroller or data-logger for further processing.
What I need from you
1. Full circuit schematic (transmitter and receiver).
2. PCB layout and working model with files and complete bill of materials with readily available parts.
3. Firmware or modulation scheme documentation that shows how the sensor bytes are encoded, transmitted, and verified on reception.
4. Recommended antenna design and alignment notes to achieve the stated 5 km range.
5. Brief test procedure so I can replicate your range and reliability results before moving to production.
If you have previous experience with low-band UHF/HF data links or have already built battery-powered telemetry modules, that background will be a plus. Please keep the design lean, component counts low, and regulatory considerations for 27 MHz operation in mind.