Fhz (Channels) Information for NZ Motorsport

In the first instance to clear up a interchangeable term, channels and Fhz (frequency)

A Fhz is what the radio is tuned in to, a little like in the old days we used to have an old style car radio we used to tune up and down the dial to find a radio station. What we were doing is changing the receive fhz in order to find a station.

A channel is like the presets that you memorise when you find the radio station.The channels allow you to easily come back to the radio station at a latter date, so a channel contains a fhz. In reality these terms are interchangeable and often mean the same thing.

What is  CTCSS or Tone?

Modern radios have the ability to not only hear a transmission on a specific fhz,  but they also can apply a filter. This filter is done by the way of sending a CTCSS tone. These tones are often referred to as sub-audioable as they are outside the range of what we can hear.

When set on a receiver, it will only allow you to hear the audio on the specific fhz set that contains the correct CTCSS tone. So what they do is act as a filter on the channel. While your radio may hear other transmissions or noise on the channel, if it does not contain the correct tone, it will NOT be able to be heard by the user of the radio.

What are the Dangers with using CTCSS tones?

While they sound like the answer to a lot of problems, they only work when transmitters are configured to send them. Our experience has seen that, while they are mandated, not all tracks have them set to be sent. If your receiver is configured only to hear transmissions with a tone and the organisers of the event has radios that are not set to send them, you will NOT hear their transmission.

What happens if my Receiver does NOT have a CTCSS tone set?

Nothing, what this means is that you will hear all transmissions on the fhz or channel. It will not in any way affect your ability to hear race control. The downside of not having the tones configured is that because your radio will hear everything on the set channel, you can be susceptible to hearing noise or interference.

NZ Circuit Track Fhz: 455.16875 MHz
NZ Circuit CTCSS or Tone: 179.9 HZ

Speedway Track Fhz: 455.0625 Mhz
Speedway CTCSS or Tone: 123.0 Hz