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G8JNJ

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G8JNJ
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  • Hi jOhn, Just a thought.  Perhaps the "IQ balance" button should be in the IQ section of the admin extensions page rather than in the extension itself ? All the other extension configs / setup used by the admins seem to reside there, and this may al…
  • Hi John, Great thanks for doing this. The strange thing is that one of my KiWi's was OK but the other (older one) wasn't. I just assumed that something had drifted (perhaps with the heat) as it's been very hot (for the UK) for the past few weeks. Re…
  • Hi John, The I/Q balance has drifted on one of my SDR's and I'm hearing hetrodynes at about -20dB on AM BC stations if they are slightly offtune. The current method of adjustment is a real pain :-( Please could the original method (with some safegu…
  • I'm also currently using my SDR to try and measure gain differences between various antennas. It would be very handy to have a rolling average, max and min values displayed numerically, either on or near the graph.  Some marker lines on the graph wo…
  • A good comprehensive review - but after spotting the inclusion of a name check for my SDR I would say that woudn't I :-) Regards, Martin - G8JNJ
  • Hi Phil, Nothing so exotic :-) I think this is what you are hearing. When the browser first starts up, the SDR tunes to the default frequency defined in the Admin config page. If you have previously used the SDR, the last frequency you listened to i…
  • Oops sorry, I meant Audio sample rate not ADC sample rate. Regards, Martin - G8JNJ
  • Hi Mariusz, I chose 33K (to minimise the current draw to
  • Hi, I assume part of this query and previous similar discussions also relate to the slope observed on Fax images. Has the original division ratio had to be changed as a result of recently increasing the ADC sample rate from 9,6K to 12 K ?  as this …
  • I just noticed a small error in my last posting - it should read:- "I also connected a 0.1uF capacitor between the transistor collector base and emitter to reduce noise or RF pickup by the transistor from the connecting cable." Regards, Martin - G…
  • Hi Mariusz, I used a short screened multicore cable (but you could possibly use ribbon cable if you don't transmit nearby) ) with a 9 pin female D socket as a flying lead from the KiWi and carefully soldered to the pins on the reverse of the board. …
  • Hi John, OK - I wan't sure if it was due to the Ant- Switch extension as others with the extension running were shown as upgraded on sdr.hu. I tried pulling the git file as suggested but that didn't work as I had modified some of the ant-switch defa…
  • Hi Arnie, OK great - I also heard the Faulty NOJ on 8557.1 this morning - looks like the TX is being overdriven and is producing IMD. So including your previous information, my new 'Unconfirmed" list is now:- 0.0214 GYA Northwood, UK0.1461 PEVEK, CH…
  • Hi Arnie, Following an analysis made by a friend of mine, he suggests that "The slant would seem to be because the frequency of a streamed demodulated tone from the SDR is is about 90ppm lower than the demodulated tone of the original signal". "if l…
  • Hi John, Just a thought - would it be possible to use a different colour font for the Fax presets that we know are good - so that it's easier to concentrate on the ones that haven't so far been confirmed ? This is my current list of Fax signals from…
  • Hi John, I checked 12786 Pt. Reyes, NMC last night and it was correct on 12784.1  However there is another Fax signal that is using approximately the same channel but is slightly off-frequency. I've observed that the start tones don't line up correc…
  • Hi John, I notice that some of the FAX presets are not tuning to the correct frequency. e.g.  8105 Athens, SVJ4 GR tunes to 8103.10 when it actually needs to tune to 8105. 12786 Pt. Reyes, NMC US tunes to 12784.10 when it actually needs to tune to 1…
  • Hi John, Thanks for all the FAX updates in V 1.93 - that's a lot better :-) I've also copied you on some private emails that may be of interest to you. Regards, Martin - G8JNJ
  • OK will do. Regards, Martin - G8JNJ
  • Hi John, Scrolling of the image would be fine. Maybe an Shift-right click on a suitable top alignment reference point (e.g. image border) and an Shift-left click (or similar) on the same point towards the bottom half of the image could be used to se…
  • Hi John, Some other suggestions. Would it be possible to use something like Shift - Click on FAX to align ? It's too easy to accidentally click on the image and mess up the alignment. A double action would fix that problem. Would it also be possible…
  • Hi John, Is it possible to have the option to default to the currently tuned frequency rather than the first pre-set ?  This would allow non-standard or newly discovered frequencies to be more easily used. Plus can the audio be muted when the Fax de…
  • Hi Kari, OK - that fixed it :-) Thanks for the quick reply and even quicker fix ! Regards, Martin - G8JNJ
  • Hi Ron, I don't really have a favourite. It's just that I remember using a radio with Ham Radio Deluxe that had a DX spot 'click and tune' feature that was quite useful, hence the suggestion for further discussion. It would turn the KiWi into an act…
  • Hi James, OK understood.  In that situation I think input protection diodes would probably be the least of your problems :-( Regards, Martin - G8JNJ
  • Hi James, The loop is relatively small so the level of field strength required for the diodes to generate IMD product above the noise floor would generally need to be quite high. Unless you are living very close to a Broadcast site it's unlikely tha…
  • Hi James, I replied directly but thought it may also be of interest to others. This is an interesting design, but I notice that the common mode attenuation figures are quoted as dB in a 50 Ohm system (which is fair enough in itself), however the com…
  • Hi All, I think you may be able to achieve this by using something like Auto-it (free). https://www.autoitscript.com/site/ I have used it in the past when running WSPR to change bands in different sequences depending upon the time of day or night. …
  • And another two confirmed today. 16.9691 USB JJC Kyodo News Agency, Japan 15Kw17.4281 USB 9VF/252 Kyodo News Agency, Singapore 0740-1010 1415-1815 10Kw
    in NOAA FAX Comment by G8JNJ May 27
  • Link-11 frequently appears in pairs separated by approx 3.6KHz When tuned to using USB, the lower dial frequency of the pair tends to be XXXX.7 and the upper frequency tends to be XXXY.3 Regards, Martin - G8JNJ