G8JNJ
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- G8JNJ
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- Location
- South West UK
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- Additional information
- https://g8jnj.net/web-sdrs
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Comments
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OK, Does the KiWi V2 board work when plugged into the Beagle board of a working V1 ? Regards, Martin
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Personally I'm not that fussed, but Geolocation generally seems to work OK for me, and is usually pretty good with UK based users, other countries perhaps less so. I can usually 'spot' my regular users from their location information, even if they a…
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The signal generator is one of the KiWi extensions. It generates an internal test signal, so it doesn't validate everything, but at least it will tell you if the software is working correctly. The easiest way to reflash your KiWi, would be to make a…
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It's not clear to me if you have you got one good working KiWi, and if that KiWi is made up of a collection of parts from the KiWi 1 & 2. It seems to me like there are a number of problems here, and each one needs to be individually identified. …
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Watch out if you are suing brushless fans connected to the DC supply feeding the KiWi. I have just built some linear supplies and found a couple of things. There was significant RF noise from the DC regulator (yes really) at frequencies below 1MHz. …
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Hi Bob, Shop around for a Sunon Maglev, a bit more expensive, but they tend to last. https://forum.kiwisdr.com/index.php?p=/discussion/2559/fan-quit/p1 Note that all of these brushless fans tend to generate a bit of electrical noise, produced by t…
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Wow, what sort of power level must have been present at the KiWi input to do that ? Even with relatively close spaced antennas, the coupling between them isn't usually that great. Most receivers will withstand RF levels up to about +10dBm, and I wou…
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Also, how many users are connected to each ? The waterfall will slow down when there are multiple users. Regards, Martin
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Beware of UPS's, some are VERY noisy. If you want to provide support if the mains fails, consider using a battery bank and powering the equipment directly. Regards, Martin
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Hi Christoph, That is a brilliant bit of work, and I think Peter, G3PLX, would be interested too. Now to how to combine that with the TDoA function :-) I'm located about 15km away from the Wessex site, and I could maybe generate some low power sweep…
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Does anyone know of an AM Bandstop filter with a bit less attenuation? Search through the forum, there are many threads on this subject. These should get you started on your journey. https://forum.kiwisdr.com/index.php?p=/discussion/comment/17132 h…
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It may be that V1 was just on the edge of an acceptable PSU start up / close down voltage vs. time, and the V2 isn't. It is a problem with linear supplies, as they ramp up and ramp down much slower than switched mode designs, when connected and disc…
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Works OK for me too. Operation for all modes are dependent upon the filter bandwidth in use, so the set point will vary. To mute the noise, NBFM typically requires a squelch slider setting of around 60, and NNFM requires a slider setting of around 7…
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Thinking about this, it would be even better / quicker if the url extension could login and take you directly to a specified admin page.
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Would adding an admin login password as a url extension associated with the existing /admin switch solve this problem ? or would it just be an additional security risk ? It would be handy to be able to directly login to the admin interface, without …
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As I previously stated, the size of antenna element usually specified for such antennas have only a very low value of self capacitance, maybe less than 1pF. Any shunt capacitance that may also be present, forms a potential divider, and the already v…
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The limitation with many PA0RDT antennas is the size of the plate antenna, which I consider to be too small. I've successfully used a 1m long whip in place of the capacitive plate, but I also include a series connected resistor and inductor, to act …
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Hi Jimmy, The PA0RDT amplifier has a very high input impedance, because it is designed to interface with the plate / whip element directly. It acts more like an electronic "impedance convertor" to 50 ohms, than an actual amplifier with gai…
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Yeh, that catches me out too, more often that it should. You need to clear your browser cookies in order to get the "new user" experience. Some browsers don't like letting go of all the stored settings, Chrome in particular sometimes seem …
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Most folks set it according to their location, and the default value may not always be suitable. I normally choose a strong local broadcast station, with the appropriate mode and bandwidth so that new users at least hear something when they first c…
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"Now to work on a better antenna" Ha, good luck, that's where the fun starts. As soon as you can 'see' a continuous swathe of spectrum from 0 to 30MHz with a KiWi, you begin to realise just how much noise and interference is present, that …
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If you have just got your K2, it may not so far have updated to the latest version. Have you tried doing this manually via the admin interface ? Almost any image size about 350 pixels tall, can be made to fit, but you may have to try rescaling it a …
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Sorry, my wording was unclear. I meant that the attenuator setting would be only accessible via the admin interface. If it is not made available to a user, it could be confusing if the control is still present, even if greyed out. But I now better u…
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Hi John, My personal view is that I think the attenuation slider setting should be an admin only adjustment, especially as it has a 30dB range. I also think it can be confusing when users can't adjust it (as per the initial post), and it currently t…
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As the weather was a bit better today, I decided to try adding a PGA103 preamp to the Apex clone. The signal (and noise) levels are now pretty much the same as all the other active antennas I have connected to my home KiWi. https://forum.kiwisdr.co…
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Hi Jimmy, I have now placed the improved Apex clone outside and connected it up to my home KiWi, so try it again and see what you think. Generally speaking, the performance in terms of absolute signal levels is about 10dB lower than I'm obtaining fr…
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Hi Jimmy, Thanks for those new links, most useful. In one of the Japanese links, someone has tried to measure the impedance match, but they have just connected the antenna directly to an antenna analyser, without the coax cable bing present to provi…
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Hi Jimmy, I was intrigued by your passive whip antenna, the ApexRadio 303WA-2. I did a bit of research online and managed to find some notes regarding its construction. It is basically a 1.7m long whip, connected to a 64:1 ratio broadband Unun trans…
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Thanks for the SNR update, that will be very useful for testing. Regards, Martin