Hydrogen Line Radio Telescope

---

I just keep making this project harder and harder on myself. Initially my plans called for a single antenna in a motorized altazimuth mount. I kept putting off making the mount then decided to scrap it—I'm going for a phased array instead.

Why

Phased arrays obviously complicate things significantly but they also offer several advantages:

• Can be processed later, just need a way to store output from the radios (Currently WAV in my case)
• No moving parts; more durable
• Better quality scans (more on this later in this page)

Hardware

This project's called for quite an extensive list of supplies. I went overkill and got a second HackRF for my additional radio. I could've gotten something cheaper but I'd have had to look into what would be best; I already know the HackRF is capable enough. This is the parts list for a single RF front end. I believe the radio acting as the local oscillator will be able to be split out to the various RF mixers. This brings the total number of radios to N_arrays + 1.

• 2× LNAs (one for 1420MHz and one for 70MHz)
• 2× bandpass filters (one to match each LNA)
• 2× SDRs (one capable of Tx, all capable of clock synchronization)
• Frequency mixer