A box from Array Solutions perched on my desk one morning a few months ago. I was excited. KL2R had just taken delivery of a Mini Stack Match:
The Stack Match principle allows you to phase two, three, or more antennas while maintaining a constant 50 ohms. A number of configuration options are available, including both-in-phase (BIP) and both-out-of-phase switching for ultimate stack flexibility. Being on a tight budget, I opted to purchase a two-antenna Mini Stack Match (BIP only) and use 2x1 coaxial switches to switch it in and out of line.
Although I've had limited time to test it, its value became immediately obvious. I had begun to notice the 20 and 15m paths to East Coast stations were, at times, slightly skewed to the north instead of the normal due east, thus making it difficult to work those stations using the usual NA C3 at 55 feet. This was particularly true in the early morning and evening. The European C3 pointed north was somewhat better, but I found it frustrating to have to toggle back and forth between the tri-banders to get them to hear me. When I hooked up the MiniStack Match, voila! The combination of using both antennas in the stack saved time and trouble of switching, and I could work across the entire US and Canada much more easily. Another advantage I have found is that I no longer miss those brief openings to EU and AF when I happen to be running US/VE stations on 20m. It's the best money I have spent in a long while.