by RCModelReviews » Wed Oct 27, 2010 9:11 pm
The problem with the 2.4GHz band is that it's being used for so many things now it's hard to give a definitive list of possible interference sources.
The ones that may be most likely to catch you out are point-to-point data-links. These are set up to transmit data between two points and often involve the use of high-gain antennas at each end of the link. Because of the high-gain antennas, they broadcast a fairly narrow beam of energy on the 2.4GHz band that isn't visible until your model flies into it -- at which point you get a sudden loss of control.
Those people who have "dead spots" at their flying fields or their own little "Bermuda triangles" where lockouts are frequent on 2.4GHz maybe experiencing one of these signals crossing the field in that area.
Non-agile DSSS systems (like the Spektrum) are particularly vulnerable to these sources of interference because when the system links up, it's totally unaware that there's a potentially very strong interference signal perhaps just a few hundred yards away.
The best way to think of these beams is like a searchlight operating in daylight. Unless you're actually in the searchlight's beam, you wouldn't even know it was on but -- when your model flies into one it's dazzled and falls out of the sky.
It can be difficult to find the source of these data-links because they can be miles away (hence the reason they use high-gain antennas) and perhaps even beyond visible distance at ground level.
As I said -- the potential sources are manifold and this is just one.
We've lost DSM2-equipped models at our flying field (we have several WiFi repeaters and a number of suburban/school WiFi networks hidden by some trees) but not a single FHSS system has experienced any issues.
DSM2 will continue to work just fine for many lucky people but given the choice, when buying new gear for instance, I can think of no reason at all why you'd take the extra risk of buying 5-year-old technology when there's much better stuff available (at a lower price) from other suppliers.
RCModelReviews.com, just the facts.