G8JNJ
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Beware of Ubiquiti radio links using PoE. The DC-DC convertors and plastic housings, can make them very noisy on HF frequencies. Regards, Martin
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Most likely during a contest or similar. When some of the big contests are running, like CQ Worldwide, the amateur bands are usually packed. Most contests tend to held during the weekend. https://www.contestcalendar.com/weeklycont.php Regards, Mart…
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They sound like the Indonesian / Asian fishermen that can be heard all over the spectrum on odd frequencies, often performing a lot of chanting. The Australian KiWi's in particular tend to be full of them, along with all the HF radars around that re…
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Yes, you are correct, it is Upstream, which makes more sense, and may be easier to fix.
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Looking at their spectrum display, it's the downstream DSL, that is problematic, which is odd at this level of amplitude. I wonder if they have their modem, line filters and POTS wiring setup correctly. Regards, Martin
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If the antenna details given on http://zl4md.proxy.kiwisdr.com:8073/ are correct, they are using a Mini-whip antenna. These, like most unbalanced antennas, are prone to picking up local interference, which is a pity as they seem to have a reasonable…
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I understand your point, but after buying a KiWi is it really that much to spend ? However, as an alternative idea, I was in a local "pound (dollar) store" the other day, and noticed that there were several small metal storage boxes with l…
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Personally, I'd say, don't bother. Put it in a die-cast metal box or a similar screened enclosure. It's much better, as it helps avoid interference to, and from, other devices. Quite a few previous post cover this topic. Regards, Martin
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Hi Steve, The KiWi is not calibrated in dBfs as such. If you use the waterfall and S-Meter values I previously posted, it will be close to genuine dBm values. 0 dBm = 1mW into 50 ohms. Try to keep individual strong signals at less than -20dBm and if…
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I set mine to Waterfall min (dBFS, fully zoomed-out) -110 Waterfall max (dBFS) -20 S-meter calibration (dB) -13 Waterfall calibration (dB) -10 I thought you could also set the Auto waterfall max and minimum levels, but I can't find that option. But…
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This looks like the project Peter (PD4P) started some time ago, but I may be wrong. https://forum.kiwisdr.com/index.php?p=/discussion/comment/16280 It was an attempt to visually snapshot KiWi waterfalls and an alternative to the SNR ranking, in orde…
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There was an extensive thread regarding the 393WA https://forum.kiwisdr.com/index.php?p=/discussion/comment/17852#Comment_17852
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"I would like to invest in the W6LVP" Also pretty average IMHO, I'd go for LZ1AQ, used Wellbrook or Cross Country Wireless. Check out the Loopantennas IO group, ready built PCB's on offer at decent prices. Regards, Martin
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I have not tried tilting the GPS antenna. At my location, I get good coverage to the horizon, with the polar "hole" to the North, so I don't think I'd achieve much by tilting. Regards, Martin
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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…