Ah, good old Med 1... yeah that sounds like crap sometimes like a huge AC buzz but not what I was hearing.
Dispatch or mobile could be talking and it sounded like someone keying on them. (had more of AM squealy sound effect) but no one talking made note of it. 5 or 4 TG both police and fire.
I have noticed some odd behavior last night and today as well. Some of it sounds like either changes or malfunctions in the 'voter'. In a couple of instances it sounded like the 'voter' was selecting more than one site for the transmitting unit and mixing the two audio paths together.
Some of the more intrusive noise (squeals, heterodyne,etc) make me wonder if there are timing issues between the simulcast sites.
Honestly, I believe an argument could be made that there is a little bit of both going on. Some of the noise is consistent with voter / receive issues at a site or sites. The noise ends when the transmitting unit un-keys and the audio path to the repeater transmitter is closed. The control operator or unit on a console does not have the noise and then the responding mobile unit(s) do. That would be consistent with receive audio path or voter issues.
Then there is the constant heterodyne and squealing which is new, and above and beyond the static and pops many experience. This takes place through the entire transmit cycle of the repeater, and does not change with respect to the transmitting units, hang time etc. There was little if any relief between one RF channel and another. When I noticed it the most this morning I was on the SW side, and out near the airport. It was terrible on the XTS, and about as bad on the Uniden. The further away from the SW side transmit site I was, the worse it got, until I headed downtown and closer to that site. The FM capture effect seems to eliminate it eventually. That in my mind is consistent with timing and signaling issues between the various transmitter sites.
Whatever it is, I feel sorry for the guys and gals trying to keep it all running. It has to be a total nightmare by now.
They are doing some testing and changing of the old system and probably will be adding those freqs to the new towers for better covrage and running with the Analog and Digital it looks like Fire will use the Analog with new covrage for a while till Digital issues get worked out. You may from time to time hear some tone genarater tones come across as well. Not to say they are not having some issues with the old while the make these changes. They are also waiting for some APCO anf FCC approvals before they move forward all together.