I purchased an Array Solutions SAL-30 Mark II for use over this past winter, having decided that it was finally time to become active on 160m. Lacking the room for a beverage, this seemed like the best practical RX antenna I could install. For those who just want my conclusion, based on experience this past winter season, here it is: save your money.
Here is the longer story.
1. Even though the antenna was marked as in stock when I placed the order, I was informed a few days later that it was not in fact in stock, and Array Solutions were awaiting parts. I finally received the antenna about a month after placing the order.
2. The instruction manual appears to have been written by someone whose third language is English (I'm not joking; actually, I'm being kind). As I started on the task of putting the antenna together, I found myself, several times, having to backtrack because of a lack of clear instructions. All told, the antenna took about 20 hours of work to put together in a way that satisfied me.
3. Some of the parts in the antenna kit had to be replaced: the four-foot double-walled aluminium tube had no pre-drilled holes in it. To give them their due, Array Solutions shipped me a correct replacement part as soon as I notified them. However, they said that there would be a shipping label included with the replacement part, to would allow me to return the part they had originally shipped, but there was no such label in the package that contained the replacement part.
4. The screws that ship with the antenna and go into the pre-drilled holes are of abysmal quality. The second or third one I installed simply broke when I was installing it (with just a manual screwdriver). So I went to a hardware store and purchased a replacement set of longer screws and some additional nuts, and used these parts instead, using two nuts on each bolt to ensure that they would not come loose.
5. The manual gives you no clue about how careful you have to be when installing the wires at the top and bottom of the mast, to make sure that they will not become tangled when the mast is finally erected. It also gives no clue as to how to deal with the issue that, because of the way that the holes are pre-drilled, the length of mast between two of the holes is different from the length between the other pair (by a couple of inches). There doesn't seem to be any way around this problem, so I simply shrugged and assumed that it would not make any difference to the performance of the antenna.
6. I installed the antenna as far away as possible from my tower, and also from the fence that surrounds the field in which it is placed. Lining the antenna exactly NE-SE-SW-NE took a lot longer than I expected, but in the end I was satisfied that the loops were orthogonal and closely aligned with these four directions.
7. The acid test, though, is how the antenna performs, and this is where it gets really disappointing. For comparison, the TX antennas on 80m and 160m are inverted vees in parallel, with the feed points at 90 feet. In other words, it shouldn't be hard for a real receive antenna to thoroughly outperform the transmit antennas on these bands.
8. I went through the set-up procedure as outlined in the manual, using a couple of local AM broadcast transmitters. Everything seems to work more-or-less as expected. In particular, as I "rotate" the antenna, the signals change as expected. The front-to-back is several S-points, so things look reasonable.
9. But when it comes to on-the-air use, my experience is that the antenna is nothing short of thoroughly disappointing. A quick (but accurate) description is that the front-to-back is great, but only because it is even deafer off the back than it is off the front. (By "deaf", I don't mean that the signal was weak -- that, of course, is to be expected with a receive antenna -- but that the signal-to-noise is considerably worse than the TX antenna, even in the RX antenna's forward direction, and regardless of the direction of the station to which I'm listening.) After use through most of the winter season, I don't think I've ever heard more than a couple of signals that were easier to copy on the receive antenna than on the TX antenna. Conversely, there have been many, many occasions when signals that are perfectly copyable on the TX antenna have been much harder to copy, or even simply inaudible, on the RX antenna. JA on 160m is a good test from my QTH, and I quickly discovered that if I can hear a couple of difficult-to-copy JA stations on the SAL-30 responding to a CQ, if I switch to the TX antenna I'll be able to hear, and copy easily, perhaps twice as many stations calling me. This is consistently true, not just an occasional aberration.
10. I expect to dismantle the whole expensive mistake over the summer, and add the aluminium and wire to my stash of spare bits and pieces -- while pondering what to do to really improve 160m reception for next winter.