I've used both Pixel and Wellbrook antennas. They're both great performers. I think Welbrook is shipping from the UK, so the shipping might be more expensive. Other than that, they're about equal performers and will both outperform many other receive only antennas, which, given their physical size, is quite a feat. They'll outperform most any lonwire or large wire unamplified loop. The really nice thing about those loops is that they are significantly lower noise than many other antennas. They'll cost around $500, but are well worth it. Given your location, you could literally hang it from the window or find a way to set it on a windowsill, if you have one.
There are much less expensive small loop designs available, which I've seen marketed mainly to the portable shortwave receiver market. They don't perform nearly as well as the larger Wellbrook/Pixel loops. I think that's why Mike asked what type of radio you're using. The portable shortwave receivers (Grundig, Sony, etc.) tend to be less sensitive than many mobile ham radios or other serious receivers. Putting a high gain loop like the PIxel on a portable shortwave might overload it, but it would be perfect for a receiver designed for more input. However, those less expensive loops are well matched for the portable receivers. Don't expect the kind of performance out of a portable shortware receiver that you'd get out of a serious HF receiver, regardless of the antenna. The difference will be in weak signal reception, which you're more likely to hear with the better receivers and miss with the low cost portables, regardless of the antenna. If you're trying to listen to the big shortwave broadcasters, then anything should work OK as they're typically very strong signals.
Also, like Mike said, you can homebrew. It's just wire, an amp and some way to make the wire hold it's shape. A quick Google will turn up a LOT of options.
Best regards - David
