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.

6400 Side transmissions, Is this Normal?



  • Dan TrainorDan Trainor Member ✭✭
    edited April 2019
    Hello Bill, Thanks for information about IMD illusion in the pan adapter. I understand. I get that. But it is not the symptom I am investigating. What I am looking at is not the same. Hard to explain in words. I tried to show a picture of these spurs that are FAR removed in freq from passband. dan
  • Bill -VA3WTBBill -VA3WTB Member ✭✭✭
    edited June 2020
    Sorry Dan, as far as the spurs go this goes a little deeper than my understanding. I do beleive it may be something only seen in tune mode. Maybe someone can chime in and explain better.
  • Dan TrainorDan Trainor Member ✭✭
    edited April 2019
    No problem Bill.  Thanks for all your replies and tests.  I appreatiate it.  I think I will just open a ticket with Flex.  Don't want to bother the community - as in the end I suspect it is not an issue / failure with radio.  It is just I want to understand what these "spurs" are and what they are called technically and what produces them and why etc,  Thanks again!  dan
  • Bill -VA3WTBBill -VA3WTB Member ✭✭✭
    edited April 2019
    Just found this from Gerald,,but you say the spurs are transmitting?

     Gerald - K5SDR, Employee

    • 822 Posts
    •  1479 Reply Likes

    Official Response

    Those are receiver aritifacts caused by high rf currents inside the radio getting into the ADC. They are NOT going out on the transmitted signal. The are simply not real Note that isolation decreases with increasing frequency so the artifacts will increase with frequency. 

    We could have blanked the panadapter as is done on other radios but we have decided not to do so. We like having the panadapters active while transmitting so that you can watch the bands with a second antenna.
    • Like

    • John OrjiasJohn Orjias Member ✭✭
      edited June 2020
      i did not read all this, maybe you got your question answered, but i went to the same freq. set my pan zoom to be just like yours and pressed tune.  I have 2 spurs in the exact same place as the image you posted. it looks pretty close to identical to yours. So what did they say they were, are the normal?

    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.