Welcome to the new FlexRadio Community! Please review the new Community Rules and other important new Community information on the Message Board.
If you are having a problem, please check the Help Center for known solutions.
Need technical support from FlexRadio? It's as simple as Creating a HelpDesk ticket.

5000A Hum on AM Receive

Alan CAlan C Member ✭✭
Flex 5000A - on AM receive I get a pronounced 'hum' (almost like a 60 cycle hum). Receives well on the broadcast band, but that background hum is there. This hum occurs on all bands in the AM mode.  Filter set to 6K  (default). I tried other filter bandwidths, with little difference. SSB and other modes are just fine (no hum at all).

Perhaps there is some setting that I am not aware of...

thx

Alan

Answers

  • Alan CAlan C Member ✭✭
    edited June 2019
    OK, the hum is not on all bands. on WWV 15Mhz AM - no hum. Broadcast band primarily
  • Ken - NM9PKen - NM9P Member ✭✭
    edited June 23
    I get that nasty hum even on my 6500 when the power lines behind my house are leaking profusely (like they are right now).  It seems to be coupling to the AM signal in some way.....
  • Alan CAlan C Member ✭✭
    edited June 2019
    Ken,

    Well, you are right on. I just checked 1450 AM with my Mark V - same hum!. Something local, no problem with the transceivers. Thanks for the heads up, indeed.
  • Ken - NM9PKen - NM9P Member ✭✭
    edited June 23
    I have an MFJ TNC whose wall-wart power supply used to couple into the rig somehow and put a hum on all the signals on my old IC-745. (1985-1993). When I pulled the wall wart the hum disappeared. I never figured out if it was re-radiating signals into the antenna or some kind of ground loop. You might check for this with equipment connected to your rig or sharing the same ground buss.
  • Alan CAlan C Member ✭✭
    edited June 2019
    Good tip, Ken, I have plenty of those wall warts running. I'll check them out. thanks!

    Alan, W4FBI

Leave a Comment

Rich Text Editor. To edit a paragraph's style, hit tab to get to the paragraph menu. From there you will be able to pick one style. Nothing defaults to paragraph. An inline formatting menu will show up when you select text. Hit tab to get into that menu. Some elements, such as rich link embeds, images, loading indicators, and error messages may get inserted into the editor. You may navigate to these using the arrow keys inside of the editor and delete them with the delete or backspace key.