The Mini Whip is the antenna I use the most with my SDRs; I have yet to buy an adapter so that I can also use it with my D-808. I had been searching for decent SW, MW and LW antennæ on the Internet that I'd be able to use at my apartment; and as my apartment is, unfortunately, very small (26 m², no balcony), I'd be unable to use a 'normal' SW antenna that would need to be several metres in length. After some googling around, I stumpled upon something called a 'Mini Whip' antenna and it sounded like the exact thing I had been hoping for; basically, it's an active antenna — which, unlike non-active antennæ, contain 'active' elements, such as transistors, which allow them to have a large frequency range for a comparatively small size — that was made specifically for receiving SW, MW and LW transmissions. It seems to have been created by a Dutch amateur radio operator called Rohloff Baker.
Unfortunately, however, there exist a large number of these antennæ ranging from dirt-cheap (below €5) to rather expensive (above €150) and I was unsure as to which one I should get and, as I am an on a rather tight budget, I decided to buy one from China for about €15.
The antenna arrived in a small package and I was slightly skeptical at first; the package contained an LNA (a low-noise amplifier), the antenna itself and some SMA cables to connect it to a receiver. The LNA itself gets its power from a 9V battery. Upon finding a suitable location for the antenna to reside — i.e. my window — I connected it to one of my SDRs through an upconverter and I was astonished — when using the antennæ supplied with the SDR itself (two, one-metre long retractable antennæ that would 'combine' in length to make roughly two-metres in total) I was unable to receive any MW stations and SW reception was patchy at best. However, when using the Mini Whip, I was suddenly able to hear MW stations, some LW stations a myriad of different SW stations from all over the world. Whereas before I was required to set the RTL-SDRs gain to its highest possible value — 49.8 dB —, I was now able to use a gain value of around 15 dB to receive stations; this greatly reduced the SNR of SW signals and I even managed to decode some of Radio Romania International's DRM broadcasts on SW.
The reception quality is now at around the same level of a cheap AM radio which, while definitely not great, is still an achievement.