FTDX101 using WSJT-x

Discussion in 'Ham Radio Discussions' started by W5IR, Jan 15, 2020.

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  1. W5IR

    W5IR Premium Subscriber QRZ Page

    I am having trouble getting a flat power output across the waterfall using WSJT-X or any digital program for that matter. I have tried using SSB and DATA-U modes, setting the TXBPF to 50-3050 Hz and even tried adjusting the equalizer setting. I have even tried using the DATA port with an external sound card (RigExpert TI-8) instead of using the USB internal sound card of the radio with the same results. I have no problems on the receive, audio response is flat across the spectrum.
    Yaesu told me it's not the radio, it's the software - poppycock! My IC-7300 is absolutely flat across the waterfall. Any comments from 101 users would be appreciated.

    Harry W5IR
     
  2. K7GQ

    K7GQ Subscriber QRZ Page

    I assume that when you say "flat power output", you're referring to the possibility of differing output levels across the audio spectrum (waterfall). It is completely normal for the power to fall off with audio frequencies too low or high.

    As WSJT-X corrects for this by shifting the main VFO frequency up or down in units of 500 hz, I wonder if your rig is properly defined under the Settings: Radio in Preferences.

    Question: does the main VFO frequency change when you go from one end of the waterfall to the other?
     
  3. KP4SX

    KP4SX Premium Subscriber QRZ Page

    I don't get flat audio response thru my setup either. I'm not running any rig control gadgetry. I'm using the sound card in the HP computer and I can certainly distinguish its bandpass characteristics.
    I've tried several different outboard USB audio devices and one actually worked great but the chinese warranty expired after a couple of weeks.
    In my case it kicks in a lot more ALC across the lower ~1000 of the spectrum. There's a particularly nasty wiggle in the response around 900-1000 Hz. Its not the rig.
    Its tolerable and I can live with it. I adjust the drive accordingly.
     
  4. W5IR

    W5IR Premium Subscriber QRZ Page

    Harry,
    I realize some rigs that use crystal filters in the ssb circuits don't have a flat audio TX bandpass. Since the 101 does not use crystal filter in the ssb generator it just seems to be an extreme drop off (100 watts output at 500 Hz and 40 watts out at 2500 Hz).

    Yaesu told me they heard this from others and they blame it on WSJT-X which is nonsense. My IC-7300 has 100 watts out across the waterfall with the same software. It's not a fatal issue, it's just annoying for a $3000+ radio.

    I have never heard of WSJT-X doing a correction for this, is that information in the user documentation?

    Thanks for the reply,
    Harry W5IR
     
  5. N9RVB

    N9RVB Ham Member QRZ Page

    equalizer settings in your radio? maybe turn it off so it's flat?
    tx filter bandwidth setting in your radio (in my kenwood I can set low and high side filter limits for various modes).

    You can use the split feature which automatically adjusts radio split and SW's TX freq to keep the TX roughly centered in the passband, specifically to avoid this problem.

    n9rvb Ryan
     
  6. N9RVB

    N9RVB Ham Member QRZ Page

    another thought: does your pc / soundcard driver have EQ settings that need to be flattened?
     
  7. K7GQ

    K7GQ Subscriber QRZ Page

    No Harry, it's not in the documentation but in actual practice - as long as the rig is properly defined to WSJT-X, it simply does this - basically centering the digitized audio in the center of a typical rigs passband.

    Transmitting at low power (if you wish), click low (200-300 hz)on the waterfall and see if the main VFO frequency changes. Also try it at the high end (3000 hz or so). If the VFO frequency does not change when transmitting, something is amiss in Rig Preferences.
     

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