G8JNJ

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G8JNJ
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  • OK don't worry, it was only to try and better understand a problem I encountered. I think it is due to a mismatch between directory structures. I was trying to copy a KiWi DX config across to a Flydog with a corrupted config, and back again to valid…
  • This old thread my be of interest if you are planning to use the GPIO port for antenna switching. https://forum.kiwisdr.com/index.php?p=/discussion/comment/7539 If you wish to better protect your KiWi and also reduce radiated noise, then adding some…
  • I'd say the D series looks like a possibility, especially the part with the sharp impedance peak at around 200MHz, but that's just my opinion. In addition to the impedance it presents, it will also alter the rise time of the data and clock signals, …
  • Hi John, WRT "Anyway, maybe the thing to do is add series resistors to all the SPI signals. They can be populated with 0R jumpers if there are any problems." Good idea, and it would also allow you to try some in-line SMD ferrites. I note t…
  • Hi John, Just some random thoughts for further discussion. My opinion is still that in many cases, it is strong local medium wave broadcast stations that cause the majority of problems, especially when the antenna is a broadband active loop, and tha…
  • Hi Steven, Thanks for the detailed information regarding the device topology. That has answered a lot of the questions I had, and is more reassuring for use in this particular application. Regards, Martin
    in KiwiSDR 2 Comment by G8JNJ August 23
  • Hi Steven, Interesting. I saw that the input power de-rating curve falls quite sharply on frequencies lower than 15MHz, and is not projected any lower than 2MHz. This made me wonder if the IMD performance would also be degraded on these lower freque…
    in KiwiSDR 2 Comment by G8JNJ August 22
  • To be honest it's quite difficult to tell from the SNR scores alone, however the day / night variation is a good indicator especially on the upper HF bands. This is my equivalent plot to yours. I've used Black Cat Systems KiWi SDR monitor to produce…
  • The inclusion of a balun is an attempt to resolve some of the more common issues that have been encountered with KiWi installations, that are associated with antenna and KiWi ground paths. The balun will not significantly affect the KiWi's performan…
  • Try my home KiWi. http://g8jnj.zapto.org:8073/?ext=ant_switch Note that any changes you make will affect all users
  • https://forum.kiwisdr.com/index.php?p=/discussion/comment/16536#Comment_16536 I don't think the chokes would contribute anything further. Stray capacitance between placement of the coax cable and case is likely to be a much more significant factor …
    in KiwiSDR 2 Comment by G8JNJ August 17
  • That is very odd. It sounds like intermittent network connectivity, but I assume it works OK when you use it as a normal receiver. Are you using a local network connection ? The serial number can be found on the Network tabbed page. Regards, Martin
  • Part of the discussion regarding the choice of input transformer is its performance WRT common mode rejection, which is pretty much defined by its interwinding capacitance (the lower the better). Don't become fixated by the insertion loss at very lo…
    in KiwiSDR 2 Comment by G8JNJ August 15
  • Hi Ken, I believe the message means that your router has not been configured to allow connections to the KiWi from the outside world via your ISP. When you say you were just using it, I assume you mean just using it on your own personal local networ…
  • I'd suggest checking R136 on the BB board. It is near the Ethernet connector and provides a very low ohm link between the digital and RF grounds. When I have accidentally connected +5v to the KiWi Ground in the past, by accidentally touching the +5v…
  • Hi John, If you are doing this, any chance of a one channel as wide as possible bandwidth channel ? It would come in very handy for occasional I/Q captures of some of the more exotic wideband digital modes. Only if it's not too difficult though. Re…
  • Excellent news :-)
  • "How does any SNR test differentiate a "real" signal from a spurious carrier?" It doesn't, but it's better than nothing. My request was in order to save time and effort when selecting KiWi's from the map for TDoA runs. In my expe…
  • Interesting. Unless I'm mistaken all the animated plots seem to start at 09:50. Which is a about an hour after the event in my last image. There have been several other events during the day but none quite as spectacular. Regards, Martin
  • The antenna is a 20m per side terminated vertical delta loop fed at the apex approx 20m agl running South West / North East. It is on a hilltop site in a rural area, overlooking the Southern coast of the UK. http://wessex.zapto.org:8073 - 0-30MHz …
  • "Any port in a storm! lol. Beautiful image." Surely - Any port in a Solar storm :-) A few more type II this morning. Here's a nice faster waterfall capture with drift and strong second harmonic. https://forum.kiwisdr.com/uploads/650/UECT…
  • It's interesting that the accusation is that you should have implemented various critical backup and support systems, when in fact they are using an unpaid for, voluntary, hobbiest system for their supposedly "critical safety of life" purp…
  • It's also a lengthy letter / rant, with a verbose series of personal titles which is usually a good indicator of how seriously you should take it. Another thought. Ask him for his ISP details so that you can "investigate his concerns" and …
  • Sounds like a jerk. Send them a note saying "thank you for bringing this to my attention", and that you have notcied that they have "outstanding and unpaid invoices for their previous 'metered' commercial usage of your KiWi", and…
  • Check the DIL resistor packs between the ADC output and FPGA before you do that.
  • One slight problem, and this one is for John. I've been using the waterfall time stamp function. Which has generally been OK. However if I use the very slow waterfall speed of 1Hz, the time stamps are very erratic. Sometimes they are present, someti…
  • Only if the KiWi admin has decided to put it in three channel mode during initial configuration. Plenty of previous discussions in this forum about the number of channels vs. bandwidth. From the KiWi admin configuration page. "The original Kiw…
  • OK I originally used ctrl+shift+j , but that does bring up a different console in Firefox. F12 works just fine. Note that you do have to permit automatic and multiple downloads in the browser config for it to work correctly. Thanks, Martin
  • Hmm, that's strange. Any ideas why it says export waterfall is not defined as the error message ? Regards, Martin
  • It was the Firefox browser console I used. https://forum.kiwisdr.com/uploads/933/ZO3KUYE6Z7S2.png However it worked in Chrome. Regards, Martin