SATTV:

 

gareth41:

 

In a situation like that, there is a van/truck with extendable mast they would use.  It would be driven to the top of Waiatarua - probably Quinn's Road, or if that's inaccessible they would likely fallback to using Mt Eden, Mt Wellington summits etc...

 

 

If only it was that easy, you would need to have all of the transmitters, studio to transmitter links, antenna couplers and filters all ready to go plus power to boot.

 

It could be done with a couple of containers, truck and several million dollars sitting around until something catastrophic hits, then all of the stations will have to change the direction of their STL antenna to the new broadcast location, if there were some that ran on fibre you would need to have standby fibre some ware.

 

There is a lot more too it than meets the eye.

 

If something was to be thown together for one station, sure it could be done in a few hours, but as soon as you add another station you are adding complexities up the wazoo.

 

Is something bad really happened, there is always AM radio or even FM radio from out of town such as 89.8 in the waikato, this gets good coverage into most places in Auckland.

 

John

 

They wouldn't do what you're suggesting exactly for that reason, and there wouldn't be a need to anyway.  It would just be a single FM frequency broadcasting from one location if it were a mobile broadcast.  People will scan their radios anyway so would pick it up plus any other mobile broadcasts that might be happening.

In terms of equipment needed, FM exciter with an RF power amp (likely 200W) into a stack of directional antennas (vertical polarized) to increase the gain, resulting ERP of around 1kW to 4kW depending on number of antennas and the directivity used.

Out of town signals will be weak, and very patchy at best on a battery operated radio which doesn't have very good selectivity - this why local broadcasts would still be used.  Car radio's on the the other hand will receive out of town signals without issue as their tuners are very selective and can listen down to something like -80dBm if there's no band expander fitted!  Try listening to LPFM signals in the FM guard bands on a battery operated radio - you won't get them very easily unless you're close to the transmitter - car radio's yes you'll get them a lot better - its essentially the same thing with out of town stations as the field strength is very low.