Media Releases

RNZ to retire Tihiotonga AM transmission mast

Released at 11:00 am on 16 June 2025

RNZ is retiring its AM transmission mast in Tihiotonga, Rotorua. The mast has reached the end of its service life and overlapping signals from other AM/FM sites will cover most of the transmission region. 

The closure will mean AM listeners in rural Rotorua District who currently listen to RNZ National on 1188 AM will need to retune to either 101.5 FM or 819 AM by 1 July 2025 to avoid any disruption. 

RNZ Chief Technology Officer Mark Bullen said retiring the mast is the right move given the investment required to maintain it. 

“FM performs better than AM, especially in more built-up areas. Maintaining the 60+ year old Tihiotonga mast would require significant investment, and because populations in the impacted area can access RNZ National via FM signal and other overlapping AM frequencies, it makes sense to retire the mast at Tihiotonga.”  

Tihiotonga is the fourth and final AM mast that RNZ will retire around the country in 2025, with masts in Waingawa (Wairarapa), Stoke (Nelson-Tasman) and Kairanga (Manawatū-Whanganui) already retired this year. All of these sites are covered by alternative FM and AM coverage from RNZ’s other transmission locations, and all have reached a point where they can no longer continue to operate without significant investment. 

While use of AM radio has declined since the introduction of FM, it still has an important role to play, achieving further reach and providing wider coverage than FM, this is especially important for those living away from the main city centres or in remote areas of rugged terrain. 

Under RNZ’s AM Management Plan, 15 resilient AM sites will remain operational, providing nationwide coverage to 97%* of New Zealand’s population till at least 2032. Masts which achieve the best population coverage have been prioritised and will be either replaced or repaired. 

The RNZ AM Management Plan also specifically recognises RNZ’s role as a lifeline utility and the need to support New Zealanders during and after significant civil defence events and therefore RNZ is maintaining sites with a smaller population coverage that are unable to receive other ways of accessing RNZ because of their remoteness. 

* Rural Grade AM signal, a minimum field strength of 54 dBuV/m 

ENDS  

Note to editors: More information about the closure can be found at www.rnz.co.nz/Tihiotonga