Wilfried's test report on the Alexloop in QRP digital operation

DL2YAJ, or Wilfried, has gained experience in QRP digital operation with the Alexloop antenna over the last 14 months. With a power of 5-10 watts and a short set-up time, he was able to record 1,285 DX QSOs, including impressive distances of over 5,000 km. Wilfried provides us with an insight into his everyday life with the Alexloop.

Return to amateur radio: From Miracle Whip to Alexloop in QRP digital mode

After many years of QRL-related inactivity, I returned to the shortwave bands by chance about 1½ years ago. With 5 watts of output (Yaesu FT 817) and a Miracle Whip antenna attached, I managed to make a few SSB contacts in the direction of Italy and Spain. At the same time, I was amazed by the almost permanently audible signals in the frequency range of the digital operating modes - even when there was radio silence on the bands otherwise.

With information from the Internet and after buying a suitable sound card, I also became active "digitally" a few weeks later with my modest equipment. I was able to log all sorts of contacts within Europe and one evening I even managed a QSO towards the US east coast - with still only 5 watts out and the Miracle Whip from my desk.

Since I was allowed to operate on shortwave (mainly in SSB) with a 6ele beam and a few hundred watts in my early days after being licensed around 44 years ago, I wasn't even sure at first whether someone might have just been having a little fun with me after this unexpected DX...

Alexloop, Yaesu FT891 and soundcard SCU 17

Naturally, the question quickly arose as to what might be possible with a slightly more "powerful" antenna than the Miracle Whip. As I can't install any large antennas at the moment, after a short search I came across the Alexloop (which admittedly wasn't exactly reduced in price). I was able to purchase it from WiMo at the beginning of August 2022 and pick it up there.

Since then, I have been using the small, quick to set up and very easy to tune Alexloop with an output of five to 10 watts (FT817 or FT891) on a tripod about one metre high in FT8 and FT4 modes. The entire "radio equipment" used here (i.e. without laptop and WSJT-X software) is shown in Fig. 1.

Experience - 14 months of using Alexloop:
Worked grids with 5-10 Watt Out and Alexloop (Illustration: Gridtracker)

I am still amazed at how well even DX QSOs can be made digitally with the small antenna and low power. There are now around 1,285 DX QSOs with a distance of over 5,000 km in the logbook. In 216 of these contacts, even ranges of over 10,000 km could be achieved. And in total across the antenna-side usable bands, 158 worked DXCC countries, 43 US states and approx. 1,075 grids currently fill the log (see Fig. 2).

Even VK (26 QSOs) and ZL (7 QSOs) can occasionally be worked if the - sometimes rather short - opening times of the respective bands towards the target region are utilised (see Fig. 3 as an example). With a current ODX of around 18,600 km great circle distance (ZL), significant distance increases are hardly to be expected...

PSK spots with Alexloop (QRP) on the 20 metre band on a Saturday morning (Illustration: Gridtracker)
QRP DX operation with Alexloop: bridging 20,000 km and unexpected successes with FT4

Looking at the propagation forecasts in the CQ DL for example, it is interesting to note that "many" of these contacts in the direction of VK and ZL during the morning hours were probably made over the long path. This means that in these cases the actual distance covered is probably even more than 20,000 km.

However, DX QSOs can be made relatively regularly, especially in the direction of the Caribbean, North and South America and (southern) Africa. Japan can also be reached more frequently. A better all-round view or a more exposed location might even offer some potential for optimisation in terms of QRP DX operation.

It should also be mentioned that over 40 other DXCC countries could at least be received with the antenna, although unfortunately no (complete) contacts were made there. A few days ago, for example, a contact with ZD7 could unfortunately not be finalised (despite several replies from the ZD7 station to my call). In situations like this, I occasionally wish that the Alexloop could "handle" a little more power, at least temporarily.

Rather unexpectedly, FT4 with the equipment used often seems to be "better" suited for DX than FT8. The proportion of DX QSOs in FT4 operation has so far been around twice as high in direct comparison to FT8. An example: On one of the last weekends, FT4 contacts were made with KH6 and FK, each with an output of 5 watts.

Perhaps the phenomenon outlined above can be explained by the fact that the FT4 frequency range is less densely occupied by signals from other (possibly much better equipped) stations and I can therefore get through to more distant remote stations more easily or better (lower QRM level, fewer calling stations from Europe). It is also not unlikely that the relative speed advantage of this operating mode pays off positively. Since a weak signal from distant stations can often only be decoded for short periods of time, the motto in these situations is "be quick and use the short opening window for a successful contact".

Alexloop in practice: An honest assessment after 14 months of QRP digital operation

As mentioned, the Alexloop is not exactly a bargain (in terms of price). The fact that it is not weatherproof reduces its possible uses somewhat, primarily of course in rainy weather or snowfall. On the construction side, it is noticeable that the coupling loop of the antenna is fixed with cable ties. Here you could ask how stable this construction might be over longer periods of time - for example in phases of high solar radiation.

However, it can be stated without reservation that the Alexloop has so far worked absolutely smoothly and completely interference-free. The unexpectedly good (DX) results in the digital range further reinforce the positive impression. I myself - admittedly not a "studied" radio frequency expert - would not have expected, at least a priori, that it would be possible to operate successfully almost regularly halfway around the world with the minimalist equipment and from less than ideal locations. Among other things, this aspect makes QRP operation with the small antenna even more attractive.

Wilfried, DL2YAJ

Alexloop
Alexloop Hampack

The Alexloop Hampack is a small lightweight portable loop for 7-30 MHz for radio amateurs with space problems or for on the road on holiday or hiking. This ultra-light loop is mounted in a few steps without tools and can be easily tuned via the tuner built into the base, the radio's instrument serves as the SWR meter.

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