Hema Navigator 6 - 12V Charger Radio Reception Interference

Owen,

Without trying to get too technical.

Most DC-DC power supplies in use today are switch mode supplies in which the DC is rapidly switched to create a waveform that can be used by a transformer to step up or step down the voltage to the desired level.

This switching process generates undesired signals (harmonics) over a large part of the frequency spectrum. These are usually filtered (or shielded) to an acceptable level within the power supply itself.

The problem you have is in the power supply and not the radio. It sound to me that the power supply may be defective and even though it puts out the required 5V DC, it must be emitting the unwanted radio frequency signals.

To test this you will need to use a different 5V DC power supply and completely disconnect the supply you have now.

I hope this helps.

I had a similar problem.
The fix was to use a different USB cable then problem solved.

I would just turn off the radio:-)

Seriously though, is the interference on the AM of FM band.
This is not a normal occurrence with the Hema Navigator.
I had an original HN5 and now a HN6 and have no problem whatsoever.

Thanks Rob, Dodg & Bill The fault is with both AM & FM and is when I am some distance from the transmitter. ie I lose reception or get interference about 50 km less distance away than I used to. But you are correct the reception improves when I use the USB cable to charge instead of the 12v charger.
Thanks, Owen A.