Frequency offset when clicking a frequency on the waterfall

Hi John,

Some time ago the issue of the frequency offset when clicking a frequency on the waterfall was raised as issue #5. 

This has now been closed, but I'm not sure if it ever got fully resolved.

At the time there was some discussion about adding an admin configurable offset value for the tuning, so that admin's could set the CW carrier frequency to be the same as that used for AM and SSB.

Has any further thought been given to this, or have I missed the config parameter.


Martin - G8JNJ


  • jksjks
    edited February 2017
    Short answer: what was resolved is what the default behavior should be.

    Longer answer: But this behavior should definitely be adjustable on a per-user basis. But that requires there be a per-user preference storage mechanism in place. And that requirement is a little bit difficult to implement. So that is one reason all of these user configuration issues are on hold.

    The "per-user preference storage" story is an interesting one. Browsers give you cookies and a more general data storage mechanism. But for security reasons these are tied directly and solely to each domain you visit. This isn't what you want for Kiwi user configuration because what you want to say ONCE is e.g. "change the CW offset for ALL Kiwis I visit" and not have to reenter it each time for every single Kiwi you visit.

    Now it turns out there is a Javascript package available called "cross-domain local storage" which does exactly this. I have added it to the code but it is not in use at the moment. One downside is that it requires to exist and serve one constant-content file. I don't like this because the Kiwi server tries to be completely independent of any website so that it can be operated without an Internet connection. True, when connected to the Internet external sites are used to get geolocation information etc. But you wouldn't want a dependency on to access your user preferences when offline, or at all for that matter. is not actually used to store the user data. That is still done on your local browser like cookies. But it must serve this one file in order for the package to work (it's yet another iFrame hack for those of you who know about this stuff). But since is currently a single Beagle connected via my home Internet connection there is obviously a reliability and succession problem (e.g. if I get hit by a bus).

  • Hi John,

    Ah OK. I had only considered it to be an admin configurable off-set on a KiWi by KiWi basis rather than a global setting using stored cookies.

    Personally I'd avoid anything that relies upon connection to an external site at all costs.

    The reason I raised the query was that one of my users commented that most Amateur operators tend to use a 650Hz off-set when tuning to CW stations rather than the current default 500Hz off-set on the KiWi. I didn't know this as I'm not a CW op, but I thought it would be good to be able to change it as required.

    Please don't action the global cookie solution for me. I think it would be too complex for too little return.


    Martin - G8JNJ

  • Most CW operators, myself included, seem to prefer 700-800 hz for the listening tone. I've thought about changing lines 698 and 699 in openwebrx.js to achieve that, but haven't because I did not know if it would have unexpected consequences elsewhere or if it would be overwritten with the next update.
    Ron - KA7U
  • I agree with the 800 Hz. The even higher tone is why people hated the Collins KWM2 CW

  • I am not sure what "most" ops prefer, but agree that many like 700 Hz and even higher.  But I think many, myself included, prefer lower tones.  I use 620 Hz, but would take the 500 Hz rather than 700 Hz any day :)   I know a few who prefer 450 Hz, but that is probably too low for "most".

  • jksjks
    edited February 2017 Accepted Answer
    Until the default is adjustable, remember that you can "BFO tune" (change the BFO tone frequency) by zooming in, putting the cursor over the yellow vertical bar of the passband and shift-click dragging. The received frequency stays the same and the passband stays the same. But the carrier point moves and so the tone of the received CW signal will change higher or lower.

    To change the passband put the cursor inside the yellow passband symbol and shift-click drag. All this is discussed here:

  • Yep, I do that occasionally, nice feature but the 500 Hz is ok most of the time.   The return to default passband feature is also very nice.  

    The narrow CW filter sure works nicely and when zoomed in it is very easy to get right on the peak with one click of the mouse.

    I did not expect to do more than play with the Kiwi for a few days and then put it on the shelf, but found it is quite nice to have running 24/7.  It is a great little device.
  • John,
    The <shift-left click> on the magnifying glass is really great. Sadly, I don't think many of the users are taking time to read the directions, at least not read them for comprehension. Still given enough time to practice, we will all figure it out. LOL
    Ron - KA7U
  • Hi John,

    I must confess that I hadn't realised (or read) about the <shift-left-click> option.

    That would seem to solve the problem, so I think this issue can be closed.


    Martin - G8JNJ
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