G8JNJ
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Hi Philippe, Guess what, I swapped out a managed Cisco switch for a cheap unmanaged 10/100 Netgear / TP-Link. The Cisco switch was producing too much noise, but the other one had enough room inside for me to be able to rotate the internal PSU board …
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Or the cables have not been wired correctly. We once discovered that a contract wireman didn't realise that the pairs were not pinned out consecutively. https://networkcodex.net/r/rj45/ Regards, Martin
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Hi Philippe, It could be a ground loop or something similar, although I have tried my best to avoid them. Maybe one of the other sdrs on site is providing a path from the Ethernet port to the antenna distribution. Another possibility is that the pre…
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Yes, it is a problem, especially on the upper HF band, and this is partially why many folks have tried to move towards a USB wireless connection with their KiWi's. My Ethernet cables are all screened, and pas though ferrite at each end. But I still …
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Ah, that's probably where my thoughts originated. I must have seen it, but didn't remember the detail. Job done :-) Regards, Martin
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Hi Rob, Just some thoughts, In order to extend the KiWi to cover additional bands, I was musing over an idea to implement a configurable external down convertor. The main issue seems to be switching RF filters to avoid aliasing from the mixing produ…
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Hi John, Personally I'd like the option to list the frequencies and modes that users have tuned to, but I realise that may become a bit too large to accomodate. Perhaps just list frequencies that have been listened to for a long period of time ? or …
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I see the same behaviour on my home sdr, 198kHz is tagged to select Ant 2. http://g8jnj.zapto.org:8073 Regards, Martin
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That's interesting. I've always been surprised that NBFM hasn't been used on the lower frequencies. There is certainly a strong feeling that it is not appropriate on the Amateur bands, even though it was one of the modes originally used on 160m, bac…
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OK, using ant followed by a comma and then the antenna number does work. If you edit the DX label, you may then have to refresh the browser session before the switch command will function. Regards, Martin
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I thought it was possible by adding the appropriate command into the extension part of the DX label editor. e.g. ant_switch,3 However, I couldn't get it to work, but I may have got the syntax wrong. Regards, Martin
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Hi Tim, I'm a bit surprised that you need to use an amplifier with the Delta loop, but is the signal level low, or are you using it to make up for splitting or other system losses ? How are you evaluating the difference in SNR between the KiWi and y…
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https://forum.kiwisdr.com/index.php?p=/discussion/comment/17035#Comment_17035 I performed some measurements on the cheap Chinese filter boards mentioned earlier in this thread. I tried the 50V 4A version which had 22uH inductors and 470uF capacitor…
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Looks like there was a CME causing a M1 & Kp7 / G3 event. More unsettled space weather is predicted for the next few days. A few occasional noise bursts today, but nothing like yesterday. Regards, Martin
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Yes, GPIO Regards, Martin
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The Sun has been very busy all afternoon, with typically one or two bursts every few minutes. Here's a big one lasting about 20 seconds, and covering from 20 to >60MHz, with the signal level peaking 30dB above the noise floor at around 35MHz. ht…
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Ha, I also noticed that problem, this afternoon, when I changed the existing default antenna to another. I think this may be the same as the problem I reported, where I had to turn mixing on and back off again to restore normal operation. Regards, M…
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Yes, I suggested that configuration to John, to alleviate the problem of an antenna being too close to a VHF/UHF antenna. The attenuator would have most likely survived, but I was concerned about IMD being generated whilst RF was present. Regards, M…
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Hi John, Ah OK, I thought we had discussed this problem a while ago, but I think we must both of misunderstood what each other was trying to convey at the time. Never mind, no great concern. Regards, Martin
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Hi John, Ah OK, I think I've seriously misunderstood, how the SNR values are derived. I thought that rx.linkfanel.net simply took the internal values from the /snr URL extension. I think I've become confused by the internal and external headings on…
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Dear Martin, Thank you very much. It is : http://sdr.autreradioautreculture.com:8074 QTH : Trémolat, Sud-Ouest, Périgord, France Best regards, Philippe Hi Philippe, Now it has gone dark, your KiWi sdr score is very impressive. I think this is becau…
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Hi Artur, Please don't turn off your SNR measurements for my sake. There are plenty of others that are skewed because of masked frequency ranges. I was not specifically singling yours out, it was just that they were the best example of the underlyin…
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Well, especially since you worked so hard for it (antenna and frontend optimizations, and all the knowledge you've shared on the forum). Thanks John, But you forgot to mention all the hassle I have caused too... The KiWi is an excellent product, and…
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Attention. If I add gain... I will move to the front, to the top of the list. Ahaha ;) Best regards, Philippe Excellent, anything to improve the deployed KiWi's performance is good news. So many have poor antennas and so much noise to be almost un…
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Yeh I know, I have posted a new issue on his Github repository, but I doubt it will result in any action being taken. It's not a big issue, I just like legitimately being at number one, for most of the time :-) Regards, Martin.
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Looks like rx.linkfanel has redone his algorithm so as not to reward those stations with a ridiculously high SNR due to the large and/or numerous masked sections. I don't know if anything has changed in the meantime, but the co-sited Polish KiWi's w…
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Ah OK, understood. I just wanted to make sure you stayed safe. Regards, Martin
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There are many countries where I wouldn't consider hosting a KiWi for all sorts of reasons, and China is one of them. To satisfy my own curiosity. Is it possible, or even sensible (possible allegations of spying, or assisting an enemy state) to depl…
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An easy test is to terminate the KiWi RF input with a 50 ohm load, and see if the noise floor rises with the power supply you wish to test. If it does, then the supply is really noisy, and it will be very evident if the setup shown below is used. …
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Personally, and despite owning one, I hate the iPad, the built-in or enforced obsolescence that makes reuse impossible, plus all the associated proprietary interfaces and accessories. They are forever messing around with stuff in updates, that usua…