On Wednesday, October 1, 2014 6:05:28 AM UTC-7, wrote:

I understand the rationale behind making various features on the Core Plus chargeable, and I have no objection to the other features which have only secondary relevance to electronic conspicuity. I still find it difficult to understand why the capability of increased antenna coverage has apparently been categorised as an additional, chargeable 'feature', discouraging users from fitting a second antenna.

I like your use of 'conspicuity'.

While it is theoretically possible to have really good coverage in one direction and basically none in another direction, my experience with a number of different gliders is once you get the 'A' antenna right with a good view out the front to cover converging traffic you generally have more than enough coverage out the back (or along the wings, or wherever the "dead spots" are). The speeds for overtaking traffic are such that you are more than fine if you can get half a mile to a mile. That's why I say that the "B" antenna seems most useful to extend the blind spot range from "fine for collision avoidance" to "good for full tactical coverage" (for cases like jfitch mentioned - the leeches were never collision threats, just competitive ones).. You just don't get situations where you have good coverage everywhere except a narrow corridor that is basically zero range and therefore a collision threat. The physics of radiated energy declining with R-squared just doesn't allow it and gliders are too thin and delicate to block a signal that completely.

At US$54, it is hardly a bank-breaker for anyone who owns a glider. I think forcing everyone to pay $54 extra for a feature that less than 10 percent might use seems like the wrong call.

9B