G8JNJ

About

Username
G8JNJ
Joined
Visits
2,098
Last Active
Roles
Member
Points
400

Comments

  • 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…
  • 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…
  • 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…
  • on v1.587 and WSPR works OK for me. Is it still a problem ?
  • 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
  • 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…
  • 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 …
  • 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…
  • Search the forum for MP1584 Regards, Martin
  • 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…
  • Yes that's a lot better, for me anyway :-) Thanks John.
  • Hi John, Some worthwhile additions in this release. A suggestion. The gaps when the distance and age are not present, tend to make my eyes zig zag down the text columns (but maybe that's just me). Would it be possible to add some guide rulers or alt…
  • Building the hardware yourself doesn't really solve the problem long term. If you just want that, keep your eyes on the auction sites for second hand units. The main issue is on-going software support and keeping the servers running so that things l…
  • One of the main problems the KiWi and clones are facing is global supply issues. This is not just confined to SDR's like the KiWis, lots of other products are also affected, as you will know if you have tried to obtain a Raspberry Pi in recent times…
  • Maybe try flushing your browser cache ?
  • Have you tried using the Custom Colourmap Extension to define your own?
  • If it works OK on your local LAN, and other kit can be remotely accessed without any issues, then that rules out your network, switch and router. So it has to be something that your ISP has done recently, despite their denials, such as plant, hardwa…
  • You have a lot of kit running. Is it possible that something is hogging a lot of bandwidth ? If it works on the local network, I suspect your ISP is doing something with your upstream traffic, maybe throttling it back for some reason. Usually becaus…
  • Hi Don, It looks like some sort of networking issue. In situations like this I usually ask myself "what has changed ?" Some initial thoughts. Have you moved any cables or wiring ? Have you altered your network configuration or added any ne…
  • Hi John, That sounds about right. I've been trying to make some A/B antenna tests using PSK reporter, and in comaparison to WSRNET it's almost impossible. Which is a pity as several runs of WSPR take ages, whereas FT8 should theoretically be much fa…
    in FT8? Comment by G8JNJ February 14
  • https://forum.kiwisdr.com/index.php?p=/discussion/comment/15568#Comment_15568 Hi Glenn, Yes maybe, but I thought John was looking for inspiration to make the extension more visually 'interesting' :-) PSK Reporter is currently suffering quite badly f…
    in FT8? Comment by G8JNJ February 14
  • Understood,. How easy would it be to plot the stations spotted on a map like that used in the HFDL extension ? Maybe different colours for different bands or S/N scores ? That would be another way to visualise real time reception and propagation, an…
    in FT8? Comment by G8JNJ February 14
  • OK maybe I'll do some more experiments, to see if I can find a better compromise. To me the grey isn't that grey, but it seem to have a pink tinge to it, which is off as it seem to be present on several different screens. I don't know if this is du…
  • Hi John, That would be really useful if you can get it to work, as it seem to be more useful than WSPR for some propagation monitoring, simply because there are so many people now using it. Maybe it could send spots to PSK reporter ? I'm not sure if…
    in FT8? Comment by G8JNJ February 13
  • "If you look at the WINB 10 kHz wide transmitted signal, half of it is DRM (and when decoded shows the BW to be 5 kHz) and the other half is a non DRM data signal. The FCC filing showed that WINB adds a low level DRM signal with the non-DRM dat…
    in DRM Heard Comment by G8JNJ February 12
  • I've now had a chance to listen to a mix of different NBFM off-air signals. To me the de-emphasised audio sound slightly muffled, but not excessively so. The UK CB band that uses NBFM radios specifically designed for the UK market, sound acceptable,…
  • I think the issue with what Wayne is hearing, is down to the frequency at which the de-emphasis kicks in. John has implemented a true definition of 6dB per octave with the break point occurring at 400Hz. With that break point, and de-emphasis on, …
  • Hi John, Thanks for that. Unfortunately I have discovered that the colour scheme I suggested for the Slow Dev and Peak hold traces don't work at all well on a small screen or tablet. It could be that the spectrum in Yellow and Peak hold in Cyan and…
  • Hi Wayne, OK that's good and is what I'm seeing too. I have done a bit more research and the problem seems to be that there isn't really a specification for Narrow Band FM pre/de-emphasis, other than the curve should have a 6dB / Octave or 20dB/Deca…
  • Hi Wayne, If you use SDR console, can you open out the spectrum analyser to up to 20KHz. I'd like to know if you see the NFM spectrum with a second band of stuff between 12 & 18kHz that t can be seen in one of my previous plots. Regards, Martin