G8JNJ
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When using an MLA-30, I don't think you can have too much gain :-) Auto waterfall settings can have you chasing your tail. So I tend to set the KiWi waterfall & Spectrum display to manual, zoom fully out to see the whole spectrum, then set the…
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The gain control on the bias tee is a passive one, so it's probably best to set that for minimum attenuation and maximum signal levels anyway. Then adjust the gain control on the loop amplifier board. There is no point adding more gain than necessa…
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If you simply combine the two antenna's, you will change the direction of the bi-directional pattern, but you will not achieve an omni-directional response, unless you combine them using a 90 degree hybrid to produce circular polarisation. Better to…
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This is a typical data sheet for the type of ceramic patch used in the small GPS puck. https://datasheets.kyocera-avx.com/ethertronics/AVX-E_1001039.pdf Note the 70x70mm PCB ground plane used in the measurement test setup. The 30x30 PCB inside the p…
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I watched one of Techmind's video's relating to the End feed antenna. https://youtu.be/VYt3-jkBfaQ?feature=shared Some things of note. He is on the edge of rural farmland, so the noise floor will be lower than if he was in the middle of at typical U…
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Hi John, Not a big deal, but it may be related to the mouse behaviour. I notice that sometimes when I click on the waterfall, the KiWi doesn't tune to that frequency, but it remains on an existing frequency. A second click is then required before it…
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An End Fed wire antenna is by it's nature not balanced, and they have a reputation as tending to be noise magnets. A wire dipole, loop or active loop are better options. With your KiWi a lack of signal level seems to be the main issue. Even if there…
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Unbalanced antennas are prone to noise pickup on the feed line. Use a balanced antenna if you can, as this will provide better results. Concentrate on the Signal to Noise Ratio rather than absolute signal strength. A good transmit antenna is not nec…
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The GPS puck is designed to mounted on a car, so it has to be siting to a metal surface in order to have an adequate ground plane, and function correctly. It doesn't need to be anything sophisticated, and something like a biscuit tin, or similar, is…
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Hi Willie, I'm using Firefox running under Windows, and I'm not seeing this happen. Have you tried another browser with Linux ? Regards, Martin
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Just select one of the frequencies using the mode you require, and then click on the main waterfall, or type a new frequency into the frequency entry box to retune the KiWi.
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In my linear supplies, I had to swap conventional silicon rectifiers for Schottky types, as the 1.6 voltage drop and 3A + forward current was producing about 5 w of heat. The downside of Schottky types, is that they have faster switching times, and …
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If you leave the HFDL map up, and scan through a few different frequencies, it's often surprising what pops up. From my UK location, I can receive aircraft and ground stations from pretty much any part of the world, but the Pacific region tends to r…
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To be honest, I'm not surprised. Many European based short wave broadcasters in the 31m / 9MHz band are massive signals during early evening / night time here in the UK, and we are not even in the target service area. I have to reduce their level b…
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OK I think that is broadcast jamming. Maybe something like this. https://groups.io/g/UDXF/topic/106337751 Regards, Martin
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It looks like a modulation sideband from the Radio China broadcast station, I'd guess it was similar on the others sideband too. The music played on Radio China, tends to include a lot of flute type instruments, which produce extended sidebands with…
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Military STANAG 4285 most likely from Australia Regards, Martin
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Unfortunately I've had the same sort of experience's Best to link to some external chat service, or not bother. I have turned off the name / callsign login for similar reasons. It seems to be like a form of graffiti, and once "tagged" more…
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You will have difficulty decoding anything from that signal, it is US Navy, 850Hz shift 50bd KW-46 Encrypted, Lualualei, Hawaii. Try using some of the KiWi's preset stations in the FSK extension, to get a better "feel" for the different sh…
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Hi Henrik, You can convey a lot in 16 characters with a concise choice of words, more if you abbreviate. I just used a short phrase and waited for a reply, then sent another short phrase asking a question. e.g. Admin - Martin Who is on 6290 ? TX Whe…
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Loots like a re-spin of their previous model, but with lots more diodes. https://forum.kiwisdr.com/uploads/264/9GMCYZF1RCI8.jpg I don't know why they have taken this route, maybe to increase the power handling, who knows ? Either way, it's a big ma…
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My V1 KiWi in its original clear plastic case did produce quite a lot of radiated noise and other signals, which could be problematic if you had other radio kit in proximity. Putting it in the metal case, or better still a die-cast box, with additio…
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Ah OK, sorry my misunderstanding. I have KiWi's and other receivers sharing the same antennas, so I'll see if I can find anything similar. Regards, Martin
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Which Airspy model is it, as the architectures vary sightly. From memory, the R2 uses a local oscillator and mixer with a 5MHz IF, but I'm not sure about the Mini. I also think there used to be block diagrams and technical descriptions of the Airspy…
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If you click on the column headers Internal / HF / External on the http://rx.linkfanel.net/ webpage, it will sort that column in descending order. Personally, I like to sort by the HF value, as that is often a better indicator of actual performance.…
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Hi Ken, The private IP address is the one used by the KiWi or server on your local network. It is either automatically allocated using DHCP, or is fixed in the device configuration file or router table. The public IP address is the one your router u…
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The port is defined in the actual device configuration file. Some port numbers are used for specific purposes, like 80 for web pages or 22 for SSH, others are chosen and sometimes become a defacto standard, but the can be changed if required. Imagin…
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Which KiWi is your own KiWi, where is it located, and is it public ? Thinking about this, as this forum only allows limited information to be included in our profiles, it would probably be a good idea for folks to include their KiWi URL(s) in releva…
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Yes, still plenty around. Which KiWi did you use to receive it ? Just some general information that may be of use to yourself or others reading this. Priyom is a good source of information regarding number stations, and has a dynamic list of daily s…
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Two or three times an actual MW broadcast frequency is often observed when very strong local transmitting stations are present. In this case 3 x 1278kHz = 3834kHz Sometimes these are actual harmonics being radiated by the transmitter, sometimes they…