Since it covers such a wide bandwidth, finding a single antenna that covers the entire bandwidth is hard.
Log-periodic antennas seem to be the most suitable wideband antennas. (They are however directional, which can be good or bad, depending on the application) However, they get impractically large, and as a result unobtainable for frequencies below about 400MHz. For these frequencies, the only practical options seem to be telescopic antennas (which can be tuned for a frequency by differing the length that is expanded) or scanner antennas.
I ended up ordering this set:
- Ramsey Telescopic with BNC / Alternative: Scanner antenna with SMA
- Ramsey 400 MHz - 1 GHz log-periodic
- Ramsey 900 MHz - 2.6 GHz log-periodic
I have since acquired a RTL-SDR dongle. The dongle that I have has a TV-style 75-ohm input connector, as opposed to the 50-ohm SMA connector on the Funcube dongle. Ideally, a balun would be used to match the impedance, but as a minimum, some cables can be made up with the relevant connectors at the ends. I found this video with information on building your own, if you need the increased sensitivity that a properly matched antenna provides. Some other dongles, like the one from hakshop, a random one from Amazon and the NooElec one has MCX connectors, which seem to mostly be 50-ohm.
I have also ordered a hackRF, which has a higher maximum frequency, which requires another antenna. I'm planning to acquire this one. (The ANT500 antenna that is available for it seems like a suitable replacement for the telescopic antenna). My planned antenna set for it:
- ANT500 (buy from wherever you buy your hackRF, I used NooElec (they ship to where I live for $5...)) / Alternative: Scanner antenna with SMA / Alternative: Ramsey Telescopic with BNC
- Ramsey 400 MHz - 1 GHz log-periodic
- Ramsey 900 MHz - 2.6 GHz log-periodic
- Ramsey 2.1 Ghz - 11GHz log-periodic
Another transceiver that is available is the bladeRF. It covers 300MHz - 3.8GHz, but it has a higher sampling rate than the hackRF (and a FPGA). An upconverter that allows for lower frequencies are also available. A nice antenna set for it is:
- Ramsey Telescopic with BNC (If you want to go below 400MHz) / Alternative: Scanner antenna with SMA
- Ramsey 400 MHz - 1 GHz log-periodic
- Ramsey 900 MHz - 2.6 GHz log-periodic
- Ramsey 2.1 Ghz - 11GHz log-periodic
This discone also seems like a great antenna if you can install an outdoor antenna. It can handle transmitting up to 200W on the 6m, 2m, 70cm, ~1.3GHz ham bands. Reception is listed as 25MHz - 1.3GHz
I would also recommend a full set of converters, covering different types of antennas. Some examples:
- SMA > MCX (For MCX RTL-DR dongles to most antennas listed above)
- BNC > MCX (For BNC telescopic on MCX RTL-SDR dongles)
- RP-SMA > MCX (for WiFi antennas on MCX RTL-SDR dongle) (Cable that would terminate on the router, now terminates on this)
- RP-SMA > SMA (for WiFi antennas on Funcube / hackRF / bladeRF) (Use on dongle to give it a RP-SMA interface)
- SMA > SMA (right-angle version) (Longer version) (SMA antenna to SMA dongle)
- BNC > SMA cable (direct version) (For BNC antennas, like the Ramsey Telescopic)
- TNC > SMA (A relatively common antenna connector) (Use with SMA-SMA cable)
- N-type > SMA (A relatively common antenna connector) (Linked product allows use with SMA > SMA cable)
- RP-TNC > SMA (different gender version) (For some WiFi antennas (Linksys) to SMA radios)
- TV antenna > SMA (For RTL-SDR dongles with TV-antenna connector)
- TV antenna > BNC (For RTL-SDR dongles with TV-antenna connector)