Welcome to the new FlexRadio Community! Please review the new Community Rules and other important new Community information on the Message Board.
Need the latest SmartSDR, Power Genius, Tuner Genius and Antenna Genius Software?

SmartSDR v3.7.4 and the SmartSDR v3.7.4 Release Notes | SmartSDR v2.12.1 and the SmartSDR v2.12.1 Release Notes
SmartSDR v1.12.1 and the SmartSDR v1.12.1 Release Notes
Power Genius XL Utility v3.8.8 and the Power Genius XL Release Notes v3.8.8
Tuner Genius XL Utility v1.2.11 and the Tuner Genius XL Release Notes v1.2.11
Antenna Genius Utility v4.1.8
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.

40m harmonics on 20 / 15 / 10m 6600

Options
DL4RCE
DL4RCE Member ✭✭✭
edited June 2020 in FLEX-6000 Signature Series
Hi all, following problem:

Two Panadapters, FDX mode, 2 SCUs in use.

Both ANT1/ANT2 are terminated with 50Ohm Dummyload.

PAN1 /SCU1: ANT1/ANT1 40m 
PAN2 /SCU2: ANT2/ANT2 20m (or 15, or 10)

When I am transmitting on 7.100kHz with 100W I do get quite a strong harmonic on 14.200, 21.300 and 28.400. Signal strength gets lower from 20 to 10m. On 20m it is S9+ and I do get strong distortion on the band.

Is this behavior to be expected? I want tom work SO2R on upcoming WAG contest and since this is happens even without antennas ... listening will be **** 20/15/10 when TRX on 40m.

With "real" antennas attached problem stays the same (that was when I first noticed it).

Any help or idea is appreciated.

73, Volker, DL4RCE




Answers

  • Joe N3HEE
    Joe N3HEE Member ✭✭
    edited June 2020
    Options
    Volker, 

    You should only see the second harmonic when connected to a dummy load.  You should not see phase or wideband noise when connected to dummy loads.  Something is leaking your signal ?

    Noise usually will get much worse when connected to antennas.  It all depends on antenna separation and polarization.  You may also need to use a set of external band pass filters. 

    I have lots of issues with wideband noise and noise coming from electronic devices with switching power supplies which radiate signals on the second harmonic of my transmit frequency.  No amount of filtering will fix that type of interference.

    Joe
    N3HEE
  • DL4RCE
    DL4RCE Member ✭✭✭
    edited October 2018
    Options
    Hi Joe, thanks for the fast reply.

    I do not see any phase or wideband noise when connected to dummyloads.

    If it is typical to see the harmonic on 20/15/10m then I am Ok. Just wondered if this should happen.

    Funny thing is that with 100 or 10W the second harmonic stays at -48dbm, no matter what. When reducing to 1W it slightly drops, so this "leak" must happen before the amplifier stage!?

    And to the third part you are right, I am not talking about those influences.

    Regards

    Volker



  • Mark NS9N
    Mark NS9N Member ✭✭
    edited October 2018
    Options
    Hi Volker, just a thought, where do you have your preamp gains set. If not at zero, try that and see what happens. I was seeing all kinds of crazy things until Flex recommend that I put the gain back to zero as stated in the manual. Just a thought.
  • DL4RCE
    DL4RCE Member ✭✭✭
    edited October 2018
    Options
    Hi Mark, thanks for the reply. I tried this as well. Does not help for the harmonics. But I did see that one antenna had a "+8" which I set back to zero. Thanks for the hint.

    Regards

    Volker

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.

Comment As ...

Categories