Recent problem with band pass in saved frequencies

Hello, the best way to explain this is by video

I have saved a frequency on the waterfall in USB, but when clicking on the entry the resolved frequency is not USB, looks more like DSB?

Any suggestions

Ta Dave


  • jksjks
    edited August 2018
    No, the "passband" field in the label edit box has always worked this way. If you want a USB passband then, well, enter a USB passband like "300, 3300". Not "3000". A single number in the passband field means symmetrical around the carrier which in your case is at 5126 kHz. It doesn't care what the current mode is.

    You might argue there is a reason for changing that. The new frequency box passband entry feature does this. E.g. if you're in USB and the current passband is 1000, 2000, and you enter /500 in the frequency box, the passband changes to 1250, 1750, i.e. 500 Hz relative to the passband center of 1500 Hz. But that's because a change in the frequency box is implicitly understood to be relative to the current frequency and mode.

    When you're making an entry with the label edit box you might have entered a frequency completely different from the current frequency. You might have even chosen a mode different from the current. So why should a single passband number be relative to the current passband center? The "principle of least astonishment" ( has to be at work here.
  • Thanks, well it certainly didn't behave like I expected it to hence the post. Maybe I have missed the point, but why isn't 3000 considered to be a USB passband? Seems a little bit of a backward step to me, I click on the waterfall change the passband and mode to the desired settings, select the mode say USB and then I tend to "save to the Waterfall" I would have thought most people tune to a displayed freq and then save.
  • Hi Dave,

    I think part of the problem is that the KiWi tunes to the center of the signal when you click on the waterfall rather than to the carrier frequency in the case of USB or LSB. Hence the bandwidth is relative to that center frequency.

    There have been lots of discussions in the past about the waterfall tuning point, with arguments for and against tuning to the 'missing' carrier frequency in the case of SSB. I think most amateurs are used to tuning to the carrier, but Johns argument was that most KiWi users would instinctively click on the midde of a signal they see on the waterfall rather than to one edge or the other depending upon if it's USB, LSB or something else.

    Personally I like tuning to the carrier, as you can easily swap between USB, LSB and AM, but I understand John's point, and it's his baby :-)

    I don't think that defining the upper and lower pass-band points is a bad feature, most amateur transceivers and SDR's (usually by dragging the filter 'edges' on the waterfall) work in that way, although they may also have narrow, normal and wide presets for quick changes.

    I think it's just a quirk of the KiWi, just like any other transceiver or software application.


    Martin - G8JNJ
  • jksjks
    edited August 2018
    I think the answer here is that when "user preferences" are finally working the very first parameter needs to be "what would you like the tuning point to be?" (carrier or passband center or even something else).

    User preferences is like the admin configuration but for Kiwi users. Any user. Not just users who also own a Kiwi. The idea is that you should be able to set a preference once and then have it apply to any Kiwi you visit in the future. This is unlike the "last remembered" values (frequency, mode etc.) saved in cookies that are specific to the current Kiwi you're using. I don't want to keep having to set the carrier point preference the first time I visit a new Kiwi.

    User preferences is taking so long because it's tricky to implement. You have to side-step some browser security problems that upset getting the behavior you want (single storage applied to multiple domains).
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