Batboard

Has anyone ever heard a noise burst over a UHF trunking system that sounds like a freight train whistle or what we call a honk. The system is comprised of 8 MTR2000 UHF Repeaters with associated Raider controllers, Decibel TX Combiners, RX Multicoupler with window filter, crystal filters on each receiver, 2 Antenex 4505 antennas, TX and RX vertically separated 20' tip to bottom. The noise burst is intermittent, but when it occurs it is usually heard on a talkgroup with a unit accessing with poor signal strength. Thanks

My first question is, "When were all of the MTR2000 UHF Base Stations purchased?"

My second question is, "Where do you have the Basic 20 dB Quieting level set on all of the MTR2000 Base Station receivers; None, Bordering on the ragged edge or right on the 20 dB Quieting signal level?"