We have a low power fax transmission too - if you can hear RNZ then you might be able to get ZKLF - they're on the same site. Google for "ZKLF Radio Facsimile Schedule" for the times and frequencies. Problem is that his frequencies are tailored for local reception and are not continuous - your best bet may be 13550kHz at 0030z followed by the same chart on 16340kHz at 0045z.