BCD436HP Reception problem.

I received an Uniden BCD436HP ver. 1.03.00 on Nov 5 2014. My scanner drops an active dept. freq. every 5 sec., for 0.5 sec. Then repeats this, (on-off-on-off-on-off) for as long as the freq. is active. I have spent meany hours each day learning the in's and out's of this new scanner. I have also read the RR forums. The drops are not random as with a weak signal, but repeating like clockwork on a strong signal (4 bars). SQ is set to 2. I have 3 other scanners (different brands) that work fine. Here is what I have tried. Used an external Antennacraft discone. Put the rubber duck back on and went for a 30 mile road trip. Set ATT on-off. Changed every HOLD Timer I could find. Transmitted from my ham radio on 2 meter to the 436hp. I created a FL and scanned only that list. Also occurs on 800MHz and P25. Then finely, and most interesting, set the SQ to 0 and monitored 155.520 MHz. The speaker emitted white noise for 5 sec. Then silence for 0.5 sec. Then white noise for 5 sec. Then silence for 0.5 sec. Etc, etc, etc. Any suggestions?

BCD436HP Reception problem.