Search found 34 matches
- Wed Dec 14, 2016 4:55 pm
- Forum: RTL-SDR Discussion
- Topic: Directional antenna for GSM phone tracking?
- Replies: 7
- Views: 8790
A few random thoughts: 1. I know that RDF at VHF is usually done with small yagis. These do not have the greatest directionality (three element yagi has a main lobe that is something like 90 degrees wide). But that is sufficient to get a rough direction, particularly when multiple antennas are used....
- Fri Nov 11, 2016 10:04 pm
- Forum: Antennas
- Topic: Is wire length critical in QFH antenna?
- Replies: 3
- Views: 8639
If you wanted to be a real purist, you could probably use a quarter-wavelength stub. Although to the best of my knowledge, nobody makes a 61 ohm coax. You could also try a 12th-wave transformer, which doesn't require funky-non-existent-characteristic-impedances. https://www.cv.nrao.edu/~demerson/twe...
Frequency depends on the setup. If it is wired, it is baseband. You might be able to get a weak signal in the HF range if you're real close to the wires though. If it is wireless, like last poster said, usually in a "junk" band like 2.4GHz. For baseband video, you can upconvert it (more or less) usi...