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Today's v1.694 update is hopefully a working version of the failed v1.691,692 release of a few days ago.
See the first post of the "v1.694" thread below for the CHANGE_LOG notes.
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v1.550: high-side injection, VFO A=B, more..

From the CHANGE_LOG file:

v1.550 Aug 5, 2022

  Added "Downconverter high-side injection" checkbox to admin page, config tab.

    This is used in conjunction with the "Frequency scale offset (kHz, 1 Hz resolution)" field

    when a downconverter/transverter ahead of the Kiwi uses high-side LO injection to its mixer

    such that the spectrum applied to the Kiwi is "inverted". A good explanation of this

    phenomenon is here: www.rfcafe.com/references/electrical/spectral-inv.htm

     

    When the checkbox is set the waterfall essentially reverses all display bins/pixels and the

    audio channels swap I/Q channels meaning USB/LSB are swapped. Nothing about the polarity of

    the Kiwi frequency scale or display of the passband (yellow/green symbol) changes. The scale

    still has the lowest frequency on the left of the screen. And LSB is still on the left.

   

  The current VFO (A or B) will be copied to the other, i.e. "VFO A=B", when the 'N' key is used.

    There is also an option at the bottom of the frequency memory menu ('m' key) that does this.

   

  Admin page, WSPR extension and Public registration configuration:

    Show a warning message and disable public registration if it is enabled, and then

    WSPR autorun is setup for ALL the channels. This is effectively a misconfiguration since

    it is now impossible for any public connections to occur! Yes, there are number of publicly

    listed Kiwis in this condition (i.e. always a yellow-colored pin on map.kiwisdr.com)

   

  Sig gen extension:

    Changed "+/- 1k" buttons to be "+/- Step" (current step size).

    Frequency suffixes 'k' and 'M' can be used in Start, Stop and Step fields.

     

  The waterfall extension "interpolation" and "CIC comp" settings are now correctly initialized

    from the URL "wfi=" parameters if present.

   

  Cross compilation fix for macOS versions later than 10.15


Comments

  • Hi John,

    Thanks for implementing the "Downconverter high-side injection", very, very, much appreciated.

    It has also opened up a whole new range of Oversampling experiments to try, such as VHF Airband and 2m reception. By-pass the internal 30MHz Low Pass filter and use an external pre-amp and Band Pass Filter.

    A point to note for other experimenters. The frequency scale is out if the KiWi "Max receiver frequency" is set to 32MHz rather than the more standard 30MHz. But this can be corrected by using the "Frequency scale offset" function.

    Regards,

    Martin

  • I really love the VFO A=B feature! Thanks for adding that!

    73, Andy / DG7LAN

  • A point to note for other experimenters. The frequency scale is out if the KiWi "Max receiver frequency" is set to 32MHz rather than the more standard 30MHz.

    How so? If I setup 32 MHz mode with high-side injection set. Then set the sig gen for 1 MHz. The carrier appears at 31 MHz or 1 MHz down from 32 MHz (max) which is what I would expect.

    Similarly, setting the gen at 31 MHz puts the carrier at 1 MHz, 1MHz up from 0 Hz (min).

  • Hi John,

    Thanks for this.


    Hmmm, I may simply be tying myself in knots.


    With 30MHz set as the upper frequency limit.

    Injecting 40MHz

    No Downconverter high-side injection or offset selected, brings up an alias signal on 26666KHz

    (66.66MHz - 40MHz = 26.66MHz)

    Downconverter high-side injection on and an offset value of Zero brings up a signal on 3334KHz

    Setting an offset value of 36666 give the correct frequency of 40MHz and the frequencies track in the correct direction.

    --------

    With 32MHz set as the upper frequency limit.

    Injecting 40MHz

    No Downconverter high-side injection or offset selected, brings up an alias signal on 26666KHz

    (66.66MHz - 40MHz = 26.66MHz)

    Downconverter high-side injection on and an offset value of Zero brings up a signal on 5334KHz

    Setting an offset value of 34666 give the correct frequency of 40MHz and the frequencies track in the correct direction.

    So everything seems to work as it should, so maybe my poor maths skills may have mislead me. Is this how you would expect it to be ?

    Anyway the various frequency off-sets can indeed be accommodated as required, which is a great step forward.

    My plan now is to by-pass the input 30MHz LPF and use an external one instead, and then use external coaxial relays to switch between various Downconverted bands by using the antenna switch extension.

    Your version of the antenna switch extension already has the provision for various frequency offsets per switch position, but would it be possible to add a tick-box per switch for the new high-side injection option too ?

    Regards,

    Martin

  • Your version of the antenna switch extension already has the provision for various frequency offsets per switch position, but would it be possible to add a tick-box per switch for the new high-side injection option too ?

    Oh, that's a really good idea. Let me look into that.

    It should be possible since flipping the spectrum doesn't require a restart. And when another connection changes the antenna setting (if the extension configuration allows) then each connection already gets a message informing them of the antenna switch. So a spectrum flip and/or frequency scale offset change should be of no great surprise.

  • Excellent, thanks again John.

    My fist simple test is to try for reception of 30 - 60MHz, simply by switching between different external input filters.

    I'll let you know how I get on.

    Regards,

    Martin

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