Complete Shopping List: $300-500 Dual Detector System (Every Component)

COMPLETE SHOPPING LIST

DETECTOR 1: HYDROGEN LINE RADIO TELESCOPE

Purpose: receive 1420MHz from Sirius direction

1. RTL-SDR Blog V3 USB dongle ~$30 (software-defined radio receiver) Buy: rtl-sdr.com or Amazon
2. NooElec SAWBird+ H1 LNA ~$35 (low noise amplifier, 1420MHz filtered) Buy: nooelec.com or Amazon CRITICAL: this filters + amplifies 1420MHz
3. WiFi parabolic grid dish (2.4GHz) ~$50-75 (100cm × 60cm, works at 1420MHz) Buy: Amazon/eBay, search "2.4GHz grid dish" OR build horn antenna from aluminum sheet OR SKAO cereal box design (~$10)
4. 1420MHz bandpass filter (optional) ~$30 (reduces interference from cell/GPS/radar) Buy: radio astronomy supply shops
5. SMA cables + adapters ~$15

SUBTOTAL DETECTOR 1: ~$160-185

DETECTOR 2: ELF SCHUMANN RECEIVER

Purpose: measure local Schumann for calibration

1. Induction coil antenna ~$50-150 DIY: wind 10,000+ turns of 0.1mm copper wire on ferrite rod core (30cm) OR buy pre-made ELF antenna GitHub: MatejGomboc/ELF-Schumann-Receiver
2. Low-noise op-amp (e.g. AD797, OPA1612) ~$10 + passive components for 1-50Hz bandpass
3. USB sound card (24-bit, 48kHz) ~$20 (acts as ADC for ELF signals)

SUBTOTAL DETECTOR 2: ~$80-180

COMPUTING + SOFTWARE

1. Raspberry Pi 4 (4GB) or laptop ~$60 (runs analysis software)
2. SOFTWARE (all free/open source):

• GNU Radio: SDR signal processing
• SDR# (SDRSharp): spectrum analysis
• Stellarium: sky positioning
• Python + NumPy/SciPy: correlation
• Audacity: ELF audio analysis

GRAND TOTAL: $300 - $500