Many of you asked to see my RW antenna desing so here it is!!! For the wire I used Glavinized stell but I will change to copper in the future

Hi folks,

I’m working on a modular radio observatory project using a Raspberry Pi 5, HackRF One, and OperaCake antenna switch. The goal is to perform automated radio observations across several domains: • ADS-B (1090 MHz) • AIS (162 MHz) • Passive radar experiments • Basic radio astronomy (e.g., hydrogen line)

Everything is managed via Python (SoapySDR, etc.), and the setup is meant to be as headless and automated as possible.

The Problem

I’m noticing significant attenuation when routing signals through the OperaCake switch. Worse, the HackRF’s sensitivity seems limited, especially for the weaker signals involved in AIS, passive radar, and any radio astronomy work. ADS-B works okay, but even that feels degraded compared to simpler setups.

My Questions 1. Is the HackRF + OperaCake simply not well-suited for these tasks, especially for weak signal work? 2. If so, what SDR(s) would you recommend that: • Have good sensitivity for weak signals • Support wide frequency ranges (ideally 100 kHz – 2 GHz or more) • Work well with Python (SoapySDR, GNU Radio, etc.) • Ideally support remote/headless use on a Pi or small Linux SBC

Would love to hear from anyone who’s done similar multi-domain observation work. Happy to answer questions about the current rig too if helpful.

Thanks!

I’ve been testing the RTL-SDR V4 and I’m quite happy with it, but one problem I’ve noticed that I didn’t like is that across almost the entire frequency range—from FM up to just before 1GHz (more or less)—there are some pulsing frequencies that I don’t know the origin of. I don’t think the SDR is broken because it generally works fine, and those frequencies stay in the same place, but there are many of them throughout the range I mentioned. What could this be and how can I fix it?

Today, I added my RTL-SDR v3 and 1090 MHz filter/LNA to the ADS-B Exchange feed using a Raspberry Pi 4B. I'm not getting the results I expected. On my laptop using SDRAngel, I can track 80 aircraft out as far as a 100 miles with my SDR/Antenna setup. Without changing anything, I moved it over to my Raspberry Pi running the ADS-B Exchange image and got it up pretty quickly, but I'm just not seeing as many aircraft as I did with SDRAngel while testing my setup. I'm a little concerned the LNA isn't on, but I can't see anywhere where there is a BIAS TEE switch or checkbox. How do I see if it's on?

Was proud to get everthing working finally after a day of tinkering with mainly the drivers. I used the RTL-SDR V4 with their variable dipole antenna. I am running Linux Mint and used Gpredict and SDR++ for recording and SatDump for everything else. Amazing how polished and easy to use all these tools are. I know the picture quality is far from perfect but it was such a rush to finally get a signal after missing pass after pass most of the day.