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Higher noise floor with external speaker connected?

WR8F
WR8F Member ✭
edited April 2020 in FLEX-6000 Signature Series
What would cause a higher noise floor on the waterfall when a speaker is connected to PWR SPKR? When I am using PC Audio I have a dramatic improvement. When I switch my speaker from my PC to the radio, the waterfall turns bright green and eventually adjusts to blue again, but signals are not as strong. I have tried using other cables, and I have tried putting snap-on ferrites on the audio cable.

Answers

  • Al K0VM
    Al K0VM Member ✭✭✭
    edited April 2020
    1) Does the same thing happen if there is no antenna connected ?
    2) Does a different powered external speaker produce the same results?
    3) What radio are you using ? What version of software ?
    AL, K0VM
  • Stan VA7NF
    Stan VA7NF Member ✭✭✭
    edited April 2020
    Please remember the rf signal processed can be either:
    Antenna signal vs ground or
    Chassis signal vs quiet antenna lead, or a combination.

    Your speaker probably has a high noise figure and your chassis connection is missing or long. 
  • David-N5PSM
    David-N5PSM Member ✭✭
    edited April 2020
    Where can I find what you are saying in greater detail please?
    73 de N5PSM
  • KD0RC
    KD0RC Member, Super Elmer Moderator
    edited April 2020
    Things to consider:
    1. grounding of the rig and station accessories. does grounding or un-grounding anything help?
    2. noise from switching power supplies (does your powered speaker have a switcher or linear supply?) what happens if you leave the speaker plugged in to the radio, but disconnected from power?
    3. are you using a physically small antenna (like a mag loop) in close proximity of the radio and speakers?  if so, what happens if the ant is moved?
    4. how long are the speaker leads?  are they stretched out or coiled up (perhaps around ferrites)? does coiling or un-coiling them help?  do ferrites help?

    You want to start eliminating potential issues to home in on the actual problem.  Try changing some things to see what has an effect, good or bad.  Let us know what you find and we may, as a group, be able to see a pattern that will lead to solution.  You have already provided a huge clue - the PC vs powered speakers.

    73,
    Len, KD0RC
  • Stan VA7NF
    Stan VA7NF Member ✭✭✭
    edited April 2020
    I do not have a citation but have experimented.

    All receive input circuits are the difference voltage between the antenna lead and the chassis and one good reason to pull the chassis down to ground.  This does not include the safety ground unless the power supply case is connected to the radio chassis.
  • Tim - W4TME
    Tim - W4TME Administrator, FlexRadio Employee admin
    edited April 2020
    I suspect a ground loop

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