Amatuer radio enthusiast Rex Moncur set an Australian record last week, sending microwaves 843 kilometres from Port Lincoln's Winter Hill lookout to Mount Macedon north of Melbourne with the help of an aircraft.

Normally microwaves only travel "line of sight" but the distance can be extended by reflecting them off an aircraft between two points.

Using a pay TV dish with a rifle scope attached for accuracy the Hobart-based retiree waited for the perfect moment to be able to make contact.

The connection only lasted for about two minutes but it was enough for Mr Moncur to break the previous record, also set by him, of 828 kilometres, between White Cliffs in New South Wales and Mount Macedon.

To be able to see the aircraft as far away as possible Mr Moncur said you needed reasonable height and nothing in the way.

After a successful attempt from Yorke Peninsula, which was not a record a distance, Mr Moncur continued on to Eyre Peninsula last week.

He managed 831km from hills around Cleve and having heard about Winter Hill in Port Lincoln he thought he would try an even greater distance.

He had more success at Winter Hill on Friday morning, reflecting the microwaves from his transmitter off a plane flying out of Melbourne.

Finding an aircraft that would cross the direct line between Mr Moncur and his friend at Mount Macedon was done by monitoring the flight paths of a number of flights in the area and choosing one that crossed the line relatively close to halfway between them.

"Aircraft transmit a signal with their position all the time."

As the plane crosses the path the contact does not last long, but long enough to set a record.

To have the distance recognised as a record it will be registered with the Wireless Institute of Australia.

Mr Moncur believes it could be a world record but because there is no international body to recognise it, it will only be recognised as an Australian record.

He is keen to keep pushing his records but said he thought he was getting close to the "absolute maximum" distance possible.