OK, so I reported that the Pro-78 gave me a very nice K-band PULSE (instant on) alert a few weeks back. Now I have received my first false PULSE alerts. Pretty explainable, but basically, I drive into a shopping complex where my gym sits. There are three buildings with similar automatic door openers and another (a bank) with a security system, all pumping out K-band. When I get in sight of the openers, the Pro-78 gives me a K-band PULSE alert.
Michael B explained it thus:
I find that it is generally due to multiple door openers that are apart by a few MHz. It doubles the pulse width in the unit and appears like a strong signal when it is just 2 signals that are combined in the alarm circuitry.
Since it's in a parking lot, I don't really care. No one is speed-trapping in there anyway.