3MTR may get a power increase

There’s finally some good news for 3MTR. The Australian Communications and Media Authority is proposing to improve its transmission by changing the operating conditions of the licence, after a period of public comment.


The station known on-air as 3MTR and MTR1377 actually still officially carries its original call sign of 3MP in all the ACMA documentation, so is referred to as 3MP by the regulator. The current operators, Pacific Star and Macquarie Radio Network applied for the change in August last year.


When 3MP was first licenced, it was as a station serving the Mornington Peninsula, hence the MP call letters. Its original service area and power reflected that limited service area and it has never had a strong signal in the heart of Melbourne.


The ACMA is proposing to increase 3MP’s transmitter power and change the directionality of its radiation pattern to improve reception in northern and western Melbourne.  It is not known whether rivals will object to the power increase on the basis that it is no longer serving its original licence area.


The station broadcasts on AM 1377 from the Water Retarding Basin at Police Rd Rowville, with a maximum CMF of 2140 V with a Directional Antenna radiation pattern.

Cymomotive force (CMF) is a term used in AM radio to define the strength of the field radiated from a transmission facility. The CMF is expressed in volts; it corresponds numerically to the field strength in microvolts per metre at a distance of 1 kilometre from the transmitting antenna. It is similar to the term ERP (effective radiated power) used in FM transmission.


Specifically MTR has requested: “increasing its maximum CMF3 from 1225 volts (V) to 2010 V and to modify its current directional (DA) radiation pattern to improve its coverage of the Melbourne RA1 licence area.”


ACMA’s preliminary view is that it will approve the technical request and will “update the description of the existing commercial and community radio licence areas in the Melbourne so they are defined in terms used in the 2006 census and are consistent with the ACMA’s most recent determination of population of a licence area under section 30 of the BSA.”


The proposed changes are contained in the Draft Variation to Licence Area Plan – Melbourne Radio and explanatory paper, available on the ACMA’s website. Closing date for comments is Friday 6 January 2012.