G8JNJ
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Hi John, I'd suggest not removing the dt value, as it would be difficult to adjust the KiWi dt offset without being able to observe it, and out io of spec timings simply wouldn't decode. Regards, Martin
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Hi John, I have sent you an email introduction to someone who may be able to assist. Regards, Martin
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Hi Joe, It could possibly be done, but why not simply use a decent broadband active loop ? In most locations the performance is likely to be limited by the level of the local noise floor, and any slight difference in received signal to noise ratio b…
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The KiWi can already output a CAT command set, but the practicality is limited, as any change to the antenna configuration affects all users, regardless of the frequency the are tuned to. Search this forum for previous posts on the subject. You can …
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Hi John, I'm sorry that my suggestion has caused you so much trouble. Once again, it's one of those things that has unintended consequences, but I'm genuinely grateful for all of the hard work you have put in trying to unravel it all. I can only ho…
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It just goes to show how effective the digital modes such as WSPR & FT8 can be, especially on the HF bands. I have still received spots from others when running a transmitter into a fully screened test load via double screened coax, as there was…
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Hi John, Great thanks. I'm pleased it is set to on by default :-) Regards, Martin
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Hi John, Sorry, but I think I've found another problem, which is an unintended consequence of the preemptable decoders. When selecting one of my KiWis that has all the channels setup as preemptable for use in a TDoA session it says that all channels…
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I think the suggestion of bringing the ADC overload indication out via a gpio pin was suggested a long time ago, as a means of controlling an external attenuator or other AGC system. Maybe this could be investigated as a possibility too ? Regards, M…
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Yes I'm also observing this on one of my KiWi's running v1.594. All four channels setup as preemptable, but only two running when there are no user connections. Going to the extensions and forcing a autorun restart brings them back up. I'm also stil…
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Hi Glenn, At Weston I'm using an amplitude slope equaliser. About 10dB starting at around 5MHz up to 30MHz, plus the usual Broadcast Band notches, all placed before the distribution amplifier, as shown in the diagram earlier in this thread. Signals …
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Yes I think it is likely to limit the overall dynamic range. Regards, Martin
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Hi John, Yes I believe they are correlated as you have observed. I have a wideband RF 'sniffer' that I use for interference tracing, and I find that for some types of noise sources, especially those such as Switch Mode power supplies, the total noi…
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My two KiWi's with SNR reporting problems are OK when only three channels are set aside for preemptable operation. My other KiWi seems to be fine when all four channels being used for preemptable operation. The only difference I can think of is that…
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Hi John, It also seems to stop the SNR measurement if all four channels are set as preemptable, and maybe there are no other users. My private KiWi at home and one of my public ones have shown this behaviour. Maybe the SNR measurement receiver needs…
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Some systems (even commercial an military ones) have the sub audible tones set at far too high a level. Ideally they should be at around 10 to 15% of the peak system deviation. 1kHz in a 12.kHz channelised system using typically +/- 2.5KHz peak devi…
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Hi John, Once again some excellent upgrades, especially the WSPR and FT mode autoruns. This should allow even more use from the KiWi's when they would otherwise be unproductive. The kick explanation panel is a good idea too, I've often wanted to tel…
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Hi John, I'm not even sure it would be possible with a KiWi, it was just a thought. The way OWRX works us that you define spot frequencies and digital modes within the required profiles for specific bands. These are typically associated with a hardw…
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Hi John, This is another great addition. I can't remember if it has been discussed before, but would it be possible to have auto-run operate as a background task when there are receiver slots available, but gradually stops when more users connect. T…
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The TWR Africa KiWi which uses a similar URL, has the Owner / Admin listed as jburnett(AT)twr.org But that one seems to have an antenna fault too. Both have a very low ranking on the http://rx.linkfanel.net/snr.html list. Regards, Martin
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I just noticed in the original post UTC SNR dT Freq km age freq: 7074.00 mode: FT8 17:07:45 -08.0 -2.52 1162 R2DPZ IQ1ZS -16 17:07:45 -10.0 -2.60 722 2486 27 CQ RN4A LN28 My experience is that FT8 will not normally dec…
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V1.588 I just tried sending some FT8 to myself and varied the reference time offset of the transmitter using Bkt TimeSync https://www.maniaradio.it/en/bkttimesync.html I know that there is a some delay present in the transmitter chain due to DSP and…
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Hi Glenn, The way it is being done at the Weston KiWi site is to have a number of bandpass filters feeding separate AD8307 RF detectors. The individual broadcast band information is then used to drive an MQTT controlled stepped attenuator and indivi…
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on v1.587 and WSPR works OK for me. Is it still a problem ?
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Hi John, OK revert it. Although technically it should be better, it seems to be making the derivation of any already flawed metric even worse. Sorry, it seemed like a good idea at the time. Regards, Martin
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Hi John, Thanks for that explanation, it makes good sense. However I'm now regretting my suggestion, as it has dramatically changed the 'pecking' order on the SNR list, and from the few KiWi's I've sampled it now seems to be even less representative…
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https://forum.kiwisdr.com/index.php?p=/discussion/2844/v1-586-ft8-improvements-spec-af-misc-fixes Hi John, Thanks for taking a look at this. The SNR results of KiWi's on the same site are now much more closely matched, which is great. The down side …
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https://forum.kiwisdr.com/index.php?p=/discussion/comment/15666#Comment_15666 Maybe try clearing your browser cache. I have noticed this sort of problem becoming more frequent with other sites and not just KiWi's. Every time there is a browser updat…
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Search the forum for MP1584 Regards, Martin
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I used switched mode supplies nearly all the time these days. The only problem I occasionally find is that despite lots of filtering it is very difficult to entirely remove the switching noise on the VLF bands, typically <100 kHz that is produced…