There’s no reason for it to go silent for any period. All broadcasters deal with similar switchovers from time to time when moving studios etc.
I don’t think there would be any hard switch at the transmitter at 12am, 6am or any other time overnight.
Instead the following steps are likely:
The feed from SEN to the studio is setup, but not fed into the transmitter. This can be done days/weeks in advance to make sure that path works. This could be in place already.
4KQ start sending their feed to SEN’s studios using a timeline or similar. Basically the same idea as when talent has to broadcast from a remote studio.
SEN put the 4KQ feed into the feed they’re sending to the transmitter. Either via a fader channel in a studio console or with digital switching.
By now, the transmitter is receiving the 4KQ feed from both ARN and SEN. The transmitter feeds are adjusted so that one of these feeds is primary and the other is backup. This can easily be done without any time off air as long as one feed is connected at all times. This can be done during the day when more techs are around given the backup feed means it’s very unlikely an problem would take the transmitter off air. The SEN feed may actually be the primary at this point.
At midnight SEN switch from the 4KQ feed to their own program. This could be manual or automated depending on their system (I’d say automated given the systems they have in place to run multiple sites with unique feeds that are all a different combination of programs). ARN stop their feed and the transmitter continues on using the feed from SEN.
Then in the days afterwards the ARN feed can be removed from the transmitter site and replaced by a backup feed from SEN.
Steps 2 and 3 could be reversed to also feed the SEN program to ARN so that a backup (via ARN) remains in place until step 6 is complete.
It will be interesting to see if SEN use the extra 128kbs of spectrum that ARN didn’t use, but own, in Brisbane, which belongs to 4KQ. That will give them 256kbs which is a good chunk of spectrum, the same amount in Brisbane as Nova, Nine and now ARN.
Listening to the final breakfast with Laurel, Gary & Mark, they have recorded a song based on Graham Bonnet’s It’s All Over Baby Blue - with the lyrics It’s All over 4KQ with Laurel on lead vocals.
John Knox is in the studio this morning a will read the 8:30 AM news.
I didn’t hear it, but apparently the Breakfast team said “this is the last time you’ll hear us on 4KQ”, questions are being asked in industry facebook groups (reading between the lines), is there an announcement imminent about the entire team moving to another station (4BH)?