G8JNJ
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Don't worry if it takes several hours. I had to leave mine running overnight on one occasion when upgrading from the original SD card to a much later version. Good luck, Martin
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If your ISP is using CGNAT you won't be able to obtain a public IP address, and phoning home will not help. A Reverse Proxy is one way around the issue if it is CGNAT, but are you sure this is the actual problem and not something else ? Are you usin…
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I think option 2 is the most practical to implement, and still have a decent level of performance. You have enough space to distance yourself from the main noise sources, and option 3 involves adding potential new noise sources anyway. DSL shouldn't…
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Assuming the SD card has been removed and the 5v PSU is capable of delivering enough current under peak load. In scenario 2. Does the green activity light on the Ethernet socket flicker ? Have you tried ? my.kiwisdr.com kiwisdr.local:8073 Can you l…
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Bandstops for the Shortwave broadcast bands are easy, as you only really require 10 to 20dB at a specific frequency. There have been plenty of discussions regarding suitable designs on this forum in the past. Here are some values to get you started.…
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I think it can become too easy to concentrate on just the overall signal levels. Many of the SDR's I've looked at on line seem to have far to high signal levels on the LF bands and not really enough on the HF bands. It is best to either tailor the a…
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I just realised where I had heard a similar type of noise before. It was from a variable speed drive fan in an air sourced heat pump. The brushless fans had an electronically generated 3 phase invertor drive circuit built into them, that produced a …
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A few things to try. Find a battery powered MW transistor radio with an internal ferrite rod antenna, Tune it to an empty bit of spectrum between broadcast stations where you can hear the distinctive noise of the interference. Turn off your mains su…
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Hi John, Ah that is a useful reference, I wasn't aware of that document. Regards, Martin
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This doesn't sound good. Have you got any idea how it may have happened ? Don't wory you can confess if you have to, we have all done silly things that we wish we hadn't... Does anything look, or smell burnt ? Can you actually measure the 5v supply…
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Add /status to the end of the URL string e.g. http://kiwisdr.yensaw.net:8073/status The fourth line down should give the admin's email address. It doen't seem likley that they are on this forum, so try sending them a private message. Regards, Martin
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The nearest one I can find on the KiWi map is this one, and it is a bit of a mess, but so are a lot of the others, one of mine included :-( http://kiwisdr.yensaw.net:8073/ No admin details but there are some if you use the /status info. Regards, Mar…
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The main problem with the KiWi for this purpose is the very wideband nature of the receiver, and under conditions of nearby lightning, the coherent nature of the energy pulse often tends to drive the KiWi into ADC overload. This is less problematic…
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OK, so at least you have confirmed it's not something it your own property, which is always a good starting point. It does seem like a switched mode power supply of some sort. Does the noise vary during the day or night, or seem to match any other …
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Agreed, connecting the PE and DC negative may allow other noise external to the PSU, but present in the ground loop to be introduced. Using an AC filter with a choke in the PE line, may help to resolve that issue. Regards, Martin
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Hi John, I wouldn't bother enabling the old behaviour, as it's probably only myself who would benefit. I think if you can make the other changes it wouldn't be required anyway. Handy to know the M shortcut. I agree it's tricky to add intuitive new f…
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@HB9TMC I think you made a good point. Even though a PSU may have a metallic mains earth connection (but many don't), I think it is worthwhile connecting the DC negative to the mains earth at the point the PSU is plugged in. In addition some USB ear…
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I have been performing more tests and trying to understand the mechanism for the ingress of conducted noise from a power supply into the KiWi. As I mentioned earlier in this thread I think there are three types. Radiated noise from the power supply …
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Hi John, Thanks for this update. I understand your reasoning for the change to the memories I used to use the automatic loading of the memories to be able to go back to a frequency I'd previously quickly tuned to if I noticed that some activity had …
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They are commonly available on Ebay from China at a very low price. Get the version with the larger inductors marked 220 (22uH), as these will provide better filtering at lower frequencies. Regards, Martin
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Is the 'Photo left margin' selected in the admin/webpage ? I had to edit the image to make it fit as I wanted it to, but the position still varies depending upon the browser in use, and the page magnification that may have been set by the user. I ad…
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ROTHR is another common and less predictable system than the fixed radars such as SUPERDARN, JORN or the more recent TACMOR, and tends to pop up just about everywhere. Likewise some regions of the world seem to suffer more than others. If you take …
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I'd agree that some digital modes seem to disappear almost as quickly as they emerge, so unless it is very easy it probably isn't worth the effort of trying to incorporate them into the KiWi. I had considered mentioning Digital Voice, but as with th…
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Hi John, I think you have most of the common modes already covered, perhaps with the exception of ROS. I agree about the lack of RSID. It is becoming increasingly difficult to identify some digital modes that are being used on the amateur bands. New…
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Hi John, I have tried a few of mine and it seems to be a problem with all of them, including those on my local network. Could be because I've got so many tags in the DX file ? Regards, Martin
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Hi John, I think there is an odd problem occurring, which is proving difficult to reproduce. If I choose to add a new DX label in the admin interface, by duplicating an existing entry, it sometimes doesn't load correctly and creates many duplicates.…
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Following Peters comments, I have been experimenting with a few switched mode power supplies, and I have been trying to determine the factors contributing to noise ingress, by measuring RF noise present when using a variety of different makes. There…
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I have many personally tagged radar frequencies, and their characteristics on at least one of my KiWi sites. http://wessex.hopto.org:8075 They do not usually operate on predictable fixed frequencies, but they do tend to stay around on similar adjace…
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Right click on the KiWi waterfall In the menu that pops up, scroll down to 'save waterfall as JPG' Otherwise use the standard windows 'print screen' keyboard option and capture the whole of the browser GUI. Regards, Martin
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Noise cancellers work by using two antennas and altering the amplitude and phase of the signal received by each antenna relative to each other. This creates a directional antenna that allows you to 'steer' the antenna pattern to hopefully reduce or …