My family obtained new real estate in France (locator JN17HL) with quite a large garden. Visiting a few weeks ago, I immediately spotted the opportunity to set-up a Beverage antenna. I already did some homework. A Beverage antenna is in basic a receiving antenna consisting of just one wire. Length of the wire is at least 2 or 3 wavelengths of the lowest band you want to receive. In my case I want to receive 160m – 10m, so I have to roll out at least 320 meters of wire. Although the hight isn’t crucial, optimal hight is around one meter above ground level. With that hight your wire will be around 450 Ohms. So we need a little transformer to transform 450 ohms to 50.
Since I am not living nearby this location I want to be able to remotely listen to the Beverage. I took a cheap RaspberryPi 3+ and a RTL-SDR v3 dongle with me to set-up a remote listening station for the Beverage.
Hanging up the wire was a bit of a challenge since I had to go thru bushes and places which are densely overgrown. But in a hour or two I had around 400 meters of wire hanging. Connecting it to the balun and with brand new coax to the garage.
Then I installed my ‘remote kit’ in the garage of the house. Connecting it directly to the ADSL-modem.
After installing all the gear it was playtime! The big question was: is the RTL-SDR v3 able to proces the big signals from the Beverage or will it be overload completely?
First runs were on the LAN with rtl_tcp. I used Gqrx to listen to the RaspberryPi. It works quite nicely. The RTL-SDR has to be in ‘direct sampling’ modus to be able to reach as low as HF. The signals are beautiful. Testing with some radio friends back in The Netherlands I was able to hear their tiny signals on 160m perfectly. Great signal to noise ratio for this Beverage!
Returning home I logged in via internet and start streaming the I/Q-signals from the RaspberryPi. But the bandwidth of the ADSL-connection wasn’t nearly enough to stream al this (raw)data.
After looking around I found some software called Spyserver (from the builders of Airspy). This software compresses the I/Q-signal (so a little higher cpu-load for the Raspberry) before it sends it online. With only around 1 Mbit upload speed I can use every compression that’s available! With Spyserver it works good. I’m able to get a bandwidth of around 15kHz (with full I/Q-stream). Only downside is: it’s not possible to use Gqrx anymore because it is not possible to connect to Spyserver with this SDR-client. Actually, only SDR# (SDR Sharp) is kind of the only one which is Windows-only and gives me real headaches. I know, I know, there is an experimental version of Gqrx with Spyserver support, but this one hicks and stutters until no end. Not optimal yet.
It is really worth the effort to put up a long piece of wire in such a remote area. With the rising noise level in rural areas it is so wonderful to be able to hear all the little signals on HF again. My current set-up costs around €100,-. That is really cheap for a remote RX-station!
Maybe I will swap the RTL-SDR stick for something with more quality such as an SDRplay or even a AirspyHF+ some day. But then again, since the ADSL-bandwidth is the biggest bottleneck, I don’t know if it’s worth the investment.