G8JNJ
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To be honest, if you live in an urban area, and have the ability to do so, then the best results will be obtained by moving the KiWi to an electrically quiet location. The ITU noise curves, and my own experience, indicate that you will obtain 10 to…
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Broadband loops don't have to be mounted that high above the ground. 2m is about the optimum, and my loops are actually ground mounted in among some bushes. The key thing is to get them as far away as possible from potential noise sources. They don'…
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Hi, Yes, for a single loop connected as "A" connect pins 3 & 6 together. You don't need to use V1, V2 & Ground for a loop, those are only required if you wish to use a separate pair of dipole elements. BTW The thing that catches ma…
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I understand the reasoning behind this, but I'm slightly concerned that it may further discourage owners from bothering to install and use the GNSS antenna. This could in turn reduce the number of KiWi's available for things like TDoA runs. It could…
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Same here. I posted a review of the orignal KiWi on eHam several years ago, but I recently noticed that the whole set of existing KiWi reviews had disappeared. I don't know if the eHam reviews get automatically purged after a number of years, but th…
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Hi Serge, I suspect that for some reason, the KiWi I/Q Balance needs to be reset. I think you can only do this via the I/Q extension on a KiWi that is on the same local network as your browser, as you need to disconnect the antenna whilst you perfor…
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Don't buy the Bonito loop. Have a look at the Loop Antennas IO group. https://groups.io/g/loopantennas You will find some familiar names on there, and one or two, are offering ready built loop amplifier PCB's based on Wellbrook and LZ1AQ's designs. …
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Looks like it was a browser issue. Clearing cookies resolved it. Thanks, Martin
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"Many thanks, there seems to be so much to look at with so many tabs on the admin page." There are so many user cases that it's difficult to cater for everyone. But the more you use your KiWi, the more thankful you will become that a speci…
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You only need sufficient attenuation to take the strongest broadcast stations down by just enough to prevent ADC overloads from occurring. I generally try to keep all signals across the 0-30MHz spectrum below -30dB. If you have an existing band stop…
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It is a good idea to set an inactivity time limit. Otherwise, you will have people connect, and then leave their browser connected, even if they are not actively using the KiWi, and this prevents others from using one of the receivers. I generally s…
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Generally speaking, you are better off using WiFi if you can get it to work. Unscreened twisted pair is often better than screened twisted pair, as it doesn't provide an additional ground path. I tend to wrap my Ethernet cables with about 12 turns, …
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The key element of the KiWi is the software and after sales support that John provides free of charge, which unfortunately has been utilised by various competitors, to produce and sell "cheaper" products. This undercutting erodes John's p…
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Hi Frank, That looks clean, and the distribution of noise looks to be correct. The fun starts when you connect your antenna, mainly because of introducing other conducted paths for noise to ingress. As a further test, connect just the ground from yo…
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I have said this before, but I consider the KiWi to probably be the best radio hobby related purchases I've ever made, and it has reinvigorated my interest in Short Wave listening, and utility monitoring. Nearly every week I discover something new, …
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I'd be tempted to have a chat with your neighbour, mine have always been interested in finding out what could be causing such interference, but perhaps I'm lucky that many of them seem to be ex-engineers. As previously mentioned, it's most likely a …
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In addition. If you have more than the specified number of users trying to connect, the additional ones can "queue" to wait for the next free slot, or "camp" where they can "piggyback" onto an existing user and hear jus…
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You will have additional aliased noise contribution from the LNA, which is another reason for the 40MHz LPF. Regards, Martin
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You can place attenuation ahead of an LNA to improve strong signal handling, but the amount of attenuation needs to be chosen carefully, to take into account the LNA gain and Noise Figure, in order to ensure that the overall system Noise Figure is n…
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Ideally, you should place attenuators between the LNA and receiver, this ensures the best overall Noise Figure. However, there is a trade in LNA design between strong signal handling and Noise Figure. Most cheap LNA's don't have a sufficiently good …
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Personally, I think the internal attenuator is more trouble than it is worth. An external attenuator controlled by the KiWi, as a separate accessory, may be a better option for those that need to handle day / night propagation changes. However, in …
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You have pressed something by mistake. Bring up the right click menu, and change the default setting back to zoom. Regards, Martin
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ZeroTier is another suggestion from OpenWebRx users to circumvent CGNAT issues. Regards, Martin
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In my case, the antennas have static bleed resistors, but I don't think the "screaming" noise is being locally generated on the antenna or mast. I suspect it is some form of plasma discharge occurring on a much bigger tower that is nearby.…
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I often get extended periods of precipitation static which raises the noise floor by 20 to 30dB, it also produces a very odd "screaming" sound when listened to using AM demodulation. Download and change the attached file .txt extension to …
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I'm not sure what could be causing the problem, but it works for me, so I think it's associated with your browser or keyboard. I'd try a different browser or device, to attempt to narrow down the problem. Regards, Martin
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As per another thread. Power supplies have generally been the biggest cause of "random" issues. The electrolytic capacitors in power supplies dry out over time, and the voltage, current and general regulation go through a long period of g…
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Power supplies have generally been the biggest cause of "random" issues, so it's always worth trying another type, with a different cable and connector, just to be sure. Regards, Martin
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How far does the Chinese filter cut into the VHF airband ? The ones I have tried seemed to be acceptable. The frequency range 108-118MHz is used for navigation aids rather than voice comms, that helps provide a bit of additional separation. For e…
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My experience of building filters like this, is that the values provided by the various on-line calculators for self-supporting air spaced inductors wound from wire, is that they are not that accurate. Even when you have wound them, and tweaked than…