Maestro TX Audio has Hum

  • 1
  • Problem
  • Updated 4 years ago
  • Solved
  • (Edited)
I've been told by others that I have a hum on my transmit audio while using my Maestro.   I've confirmed the issue using FDX and listening on a second slice.  I'm using a Radiosport RS60CF Headset with M207 mic cartridge along with the Radiosport cable hooked to Mic-2 and Phones on the Maestro.  The Hum is only there while using the supplied Flex wall plug-in power supply.  I have no hum if using only a USB battery or using external 12V from my shack power supply.  The Flex power supply measures 12.1 Vdc out.

Here is a waterfall shot of my TX audio while using the Flex 12v power supply,  you can see the hum / noise on the left side of the waterfall

Here is a waterfall shot of my TX audio on a USB battery only you see the hum/noise is gone:

Is this a known issue that has already been documented or is this a possible bad power supply? 

Photo of Cal Spreitzer

Cal Spreitzer

  • 449 Posts
  • 113 Reply Likes

Posted 4 years ago

  • 1
Photo of Tim - W4TME

Tim - W4TME, Customer Experience Manager

  • 9202 Posts
  • 3563 Reply Likes
Official Response
The supplied AC switching power supply, while grounded through the AC mains, may be a little noisy, as all switching power supplies are.  As Steve (N9SKM) suggested, a few turns on a ferrite core should fix you right up.