VK5FQ | WIA Re-Broadcast

How I re-broadcast the WIA national and local news on 476 kHz LSB.

Here's a quick look at how I relay the WIA news.

Now over 200 sessions on 476 kHz ...

The Sunday morning WIA broadcast is transmitted via a number of different frequencies on the Amateur Radio bands, and available in different modulation formats.

Here, in Adelaide, South Australia, it can be heard on the local 2m FM repeater, VK5RAD, on 147MHz at 9am on Sunday mornings. Perfect. I can take the output from my 2m receiver and use it for the input to my 476 kHz transmitter on the 630m band. I currently use my Icom 275H transceiver as the 2m receiver, feeding the headphone output to an input channel of a small audio mixing desk. The received signal can be monitored via the mixing desk headphone output.

As we are limited to using 2.1kHz ssb signals in the 630m band, a normal 2.7 kHz ssb signal output will need to be shaped. This may not be a problem on newer equipment which have variable filters via DSP methods and the like, but not on the old commercial transceiver I am using. Solution, in my case, was the use an audio filter, the Datong FL3, to restrict the available audio bandwidth to the transmitter. This unit can be used to significantly limit the output of the audio mixer which can then be fed to the transmitter. Generally, the 300 Hz to 3000 Hz will give a pleasant 2700 Hz of audio on receive. The filter is adjusted so that this signal becomes 400 Hz to 2500 Hz. This matches the required 2100 Hz bandwidth requirements.

The transmitter is an ex-commercial transceiver, modified for amateur use, along with external filtering for the 630m band. The audio is fed into the external audio input port and the PTT switching is controlled by a manual rocker or footswitch switchbox. A number of channels have been programmed into the radio, for data and other ssb modes. At the end of the re-broadcast, the manual switch is bypassed and the footswitch can then be used during call backs, with audio from a local microphone, also plugged into the audio mixer. The relayed 2m audio is normally muted at this time to remove unwanted transmissions that may occur at the end of the 2m transmission.

Well, there you have it. The weekly local and national WIA news, as relayed via Steph, VK5FQ, on Sunday mornings, starting at 9am local time on 476 kHz LSB. Licensed amateurs are welcome to call in on the frequency after the broadcast has ended. Any feedback is welcome. Send via email to vk5fq at adam dot com dot au. Cheers and 73! Steph, VK5FQ.