[Discuss-gnuradio] Cheap portable antenna for SSB + CW w/
USRP1?
Since you are only interested in RX, a loop would probably work well. You could probably rig up compact, muti-turn wire loop that could be broken down and folded. A simple passive loop requires a high-Q, variable plate capacitor you must tune for resonance, so it is inherently narrow band, but that also gives you rejection. They are lossy too, but HF is dominated by atmospheric noise so noise figure is not a prime concern. MFJ-952 is a mini-loop tuner; just add your own wire. There are active loops too. This is a list:
Active loop design:
|