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 refer to the product documentation or check the Help Center for known solutions.
Need technical support from FlexRadio? It's as simple as Creating a HelpDesk ticket.

17 METERS SPECTRUM

HI ALL. I have the Flex 6300 finally hooked up and in going through the bands I noticed that on 17 meters the top of the spectrum is only 18.164 after that I cant tune or key. Where can I change that setting? VA3KBC

Answers

  • Larry Loen  WO7R
    Larry Loen WO7R Member ✭✭
    edited February 2016
    If you tune to 18.164, you are at the top of the _usable_ band because your "upper sideband" signal will top out around 18.168 (at least under US rules)
  • Don Stefanik
    Don Stefanik Member
    edited June 2020

    hhmm with my pro3 I could go right to 18.168  there are a few guys I would talk to on 18.165.

    so now I won't be able too?


  • Andreas Junge
    Andreas Junge Member
    edited December 2016
    Have you tried to reduce the TX bandwidth? Maybe you are at 4KHz right now?

    Try 3KHz. Just a guess. 

    73, Andreas, N6NU
  • Mike va3mw
    Mike va3mw Member ✭✭
    edited February 2018
    On my 6300, I can tx on 18.165 with a low cut of 100hz and a high cut of 2900.  If I increase it to 3000hz then TX is disabled.

    I bet your bandwidth is higher than 3k.  No real reason to make it higher than that other to use bandwidth you don't really require. 

    The radio is working as designed.  

    The Pro 3 was more generous, however it is up to you to ensure that you do not transmit out of band.  It is more than the carrier frequency that we look at on our dials.  That is something that a lot of new hams don't always understand (or remember).  It was likely one of those test questions.  :)

    Carrier freq is 18.165 + up to 3khz of audio takes you to 18.168.  Beyond that, you are out of band even without moving the VFO.

    Mike va3mw


    image


  • Don Stefanik
    Don Stefanik Member
    edited February 2016
    Ok. Got it thanks.
  • Ken - NM9P
    Ken - NM9P Member ✭✭✭
    edited December 2016
    @Don...Many rigs limit TX output based upon the base carrier frequency, which then allows the upper sideband signal to go out of band.  The frequency limits in the rules require the signal to be limited based upon actual signal output, rather than carrier frequency, which is off by the by the amount of transmit bandwidth either above or below the carrier frequency.  The same goes for spurious emissions.  If a guy is right at 18.168 carrier frequency and using LSB, it is OK, as long as there are no splatter or other modulation byproducts in the opposite (upper) sideband.

    Ken - NM9P

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.