G8JNJ

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G8JNJ
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  • 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 …
  • Could it be in the middle of an update ?
  • Hi, I'm sorry but your post still doesn't make much sense to me. The article in the link you provided, is referring to a problem with Windows file permissions. As far as I can see, this has no connection with any KiWI web sdr. Can you please expla…
  • Hi, I'm sorry but your question doesn't make much sense, to me at least. You don't have to install anything on a Windows PC. All you need to use a KiWi SDR is almost any web browser. The KiWi itself is a specially designed item of hardware that prov…
  • Superb :-) Thanks John. Regards, Martin
  • Hi John, Thanks very much for this, it will lend itself to all sorts of experiments. On point I should have made clearer, as the whole spectrum is reversed, the signals also become 'mirror' images, so USB becomes LSB etc. Ideally the demodulation mo…
  • Hi John, OK thanks for that. Just to clarify, if the ADC was faulty, the internal signal generator would still give the correct levels ? Regards, Martin
  • OK I'll try. Nearly all browsers have now implemented various security features to prevent the automatic playing of various types of Audio and Video media. This is intended to help prevent malware from being loaded when a bad website site is selecte…
  • >The NAVTEX/DSC extension map is only relevant when Selcall mode is active Ooops yes, sorry John, I had forgotten that, my apologies. As I said it's a while since I last used it, and I must have been confusing it with the link from the decoded sh…
  • It's a while since I last used it, but I've just tried the Navtex decoder and it starts up for me by showing Indonesia. This may be because the map 'auto zoom' selection was on, and the last reception was from that area of the world. However, I als…
  • I suspect that it's a left over from what was only originally set up for the AM broadcast band, so it may not work in its present form with other frequency spacings for what you are tryng to achieve. I guess John will confirm the actual situation at…
  • If you are just installing a new KiWi it may be best to leave it running whilst connected to the internet via your router for an hour or so. It can take this long to upload and install all of the updates that have been made since the original KiWi s…
  • Hi Nick, The LAMB-1 is basically another copy of a design by M0AYF https://wiki.radioreference.com/images/0/0d/Modified_M0AYF_Loop_Amplifier.pdf which is turn was based on the original design by John, G8CQX https://www.qsl.net/m0ayf/active-loop-rece…
  • >I have retired into a unit (1 of 6) so have limited options for an outdoor aerial but Im looking at options, maybe a mag loop or spiral loop. Yes a broadband loop would probably be a better option than the PA0RDT in that situation. With careful …
  • The Youloop only really works with Airspy products, as they have a very low noise figure and good resultant sensitivity (although it should be OK with the SDR Play, as long as you fully engage the pre-amp). This effectively makes the Youloop / Airsp…
  • Could this just be something simple ? Maybe it's just that the menu 'Off' button or 'Y' key has been pressed too many times, and the DX labels and band bars are hidden ? It's easy enough to do if you are not aware of this function. Regards, Martin
  • Just taken a listen and that's a lot better now so well done. What's the source of the noise around 2MHz ? Is it possibly from a variable speed motor drive or something like that ? Regards, Martin
  • Looking at stock levels and suitability. Your best bet may be to use a 33uH inductor and a 12nF capacitor. This type has a Q of 40 which is OK. B82144F2333J000 RF Choke, LBC+, 33 µH, 1.9 A, 0.22 ohm, ± 5%, 9 MHz Farnel.ie has stock and you don't h…
  • The number of turns you can fit on a toroid core depends upon the wire size used. However the more turns you add the lower the self resonant frequency becomes, which may be problematic in some applications. For high values of capacitance in tuned ci…
  • If you get really stuck send me a PM. Regards, Martin
  • I forgot to mention. If you wish to calculate inductors would on various core materials, this software is pretty useful as a starting point. https://mini-ring-core-calculator.software.informer.com/ Regards, Martin
  • I take your point about lack of time and family commitments, having long gone though that stage of life, and now having the luxury of retirement. I do tend to forget how demanding it was at the time, so you have my sympathies. My comments about the …
  • The ratio of inductance to capacitance sets the notch bandwidth, so you can have a wide or narrow notch depending upon the values you choose. The key thing is to use an inductor with a high value of Q and operating well under its self resonant freq…
  • Yes it's a pity that most of the commercial AM bandstop filters don't include the LW broadcast band. It's also a pity that so many folks who have paid good money and installed KiWi's don't seem to have paid much attention to the antenna system. In t…
  • Hi Ben, Yes the Chinese activity in the South China sea is very disturbing, for all sorts of reasons. This website offers more clues about who is doing what and where in that region. https://amti.csis.org/scs-features-map/ Regards, Martin
  • Hi John, It may also be worthwhile considering the Australian Outback HF networks which tend to use Codan and Barrett equipment, which I think is compatible with the UN standard. http://swld.com.au/pages/aus_remote_area.htm There are at least two se…
  • Try this section in the user guide http://kiwisdr.com/quickstart/#id-user-tune
  • Quite pleased with this one I received in the UK today. 14:37:21Z 12577.00 SAFETY Test, 003160023[Coast Station: Canada, Iqaluit] => 003160023[Coast Station: Canada, Iqaluit] 14:37:32Z 12577.00 SAFETY Test ack, 003160023[Coast Station: Canada, Iq…
  • Hi John, Does the decoder provide any Signal to Noise / BER / Quality / signal level information ? I think that would be useful if it could be made available. Regards, Martin
  • Just one 4.N message today https://forum.kiwisdr.com/uploads/474/753DVQQKBWCK.png