G8JNJ
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Thinking about this a bit further. In order to be able to plot propagation maps with results from several KiWi's it would be necessary to be able to gather up to at least 24hrs of data with UTC time stamps and GPS co-ordinates. I'm not a software…
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I'd also like to support zachliang's request to be able to download S-Meter readings as a CSV file. I've been experimenting with antennas (again) and the ability to process the data off-line would be very useful., I know I could now use kiwirecorde…
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It's working well. I have some observations based on my own experience from previously trying to setup something similar. You seem to have some switched mode power supply noise in the background, this may possibly be from the LNA ? There is still…
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My experience is that the speed varies depending upon the number of users and internet speed / latency. I think you would obtain better results using the S-Meter extension. Personally I'd like to be able to download CSV files from the S-Meter exte…
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Hi, It's difficult to tell exactly from your screen grab, but I suspect you are actually seeing and 'decoding' interference from a Switched Mode Power Supply instead of a genuine Loran transmission. Regards, Martin - G8JNJ
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Hi John, Build the LZ1AQ instead. It's a better performer and easier to construct, plus I'm not 100% convinced about George's reverse engineered circuit, especially the transformer windings and specifically the configuration on the binocular core.…
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Hi, There was a post on the subject some time ago, which may help a bit. http://forum.kiwisdr.com/discussion/comment/6604#Comment_6604 This part is the most informative. "v1.279 has improved spectrum filter options. In addition to the defau…
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HI John, OK, I must have imagined doing this. I've certainly setup TDoA tags to automatically bring up the other KiWis required to get a fix, by putting a URL string in the tag's extensions edit box, so maybe I was remembering that instead. It w…
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I suspect that when you select TDoA it defaults to I/Q for sampling ? I seem to remember asking John to so this some time ago, as I got fed up remembering to select I/Q each time I ran a TDoA session, but I'm not 100% sure if it got implemented. R…
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I just realised that I got the project reference incorrect, as I'd worked out the wrong time from the schedule. So the final session is now up and running until I estimate 18:00 UTC 14th June 2019 I can now hear the carrier being swept on the Anas…
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OK, well that looks like it could be fixed :-) Bit of low pass filtering then into a balun followed by 2 x Norton input stage (Q1/2) followed by what seems like a fairly standard push pull broadband amplifier with the transistors hidden under the t…
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> >I think half the worlds supply of silicone was used to seal every seam and screw. > So the magic smoke is probably still contained within :-) At least you can unpick silicone, go on you know you want to do it, and we all want to see wh…
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Ha, I'm 320 today with SWUKSDR/2 but not too bad considering I'm only running the KiWi decoder on 137, 475, 1838 & 28,126KHz. And to think that a few years ago, using an amateur tranceiver running 24/7 on practically all bands, I was consistent…
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Hi Giulio, I use a separate notch filter for each BC band, as I have a large broadband antenna, but you only seem to have a problem on one frequency, so it is easy to fix with just one filter. The notch with values as shown, covers most of the 7MH…
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Hi John, I have been playing with the SSTV extension which is a useful new addition and generally works very well. I find that the majority of SSTV traffic (or at least the most active frequency that can be heard most of the time) tends to be 1423…
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Interesting. I just received one from the last Massdrop that I'm currently setting up. The initial update to the latest version was taking forever. In the end I cheated and used one of my SD backups from a KiWi with a more recent version to get it…
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No, you need to either notch out the strong signal which has a minimal reduction in overall performance across the whole frequency range, or put an attenuator in line which will reduce the performance on the higher frequency bands where the natural…
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Hi Giulio, Adding a series tuned notch filter across the KiWi RF input will help reduce the problems on 7345KHz. (Image) These values give the bets compromise between notch depth and attenuation on the adjacent 40m amateur band. For this simul…
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I think a 'flesh tone' detector is required on the SSTV extension with an 'auto' blanking function - some very dubious pictures being transmitted on 14MHz mostly from Russian amateurs. Regards, Martin - G8JNJ
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Hi John, The SSTV decoder works pretty well. (Image) Oona has some interesting stuff on her webpages, I had posted a link to her split band descrambler on another forum earlier this week. Regards, Martin - G8JNJ
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Mainly with Chrome but it may apply to other browsers too. You may still need to change the site settings for a specific web page. Right click on the icon at the left hand edge of the browser URL to 'view site information'. Then select 'Site sett…
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"The problem with that feedback approach is that the loop gain falls to zero at the desired operating point (no OV, ever). There is also the issue that broadband attenuation hurts sensitivity/noise floor everywhere." Yes that's true, and …
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Yes, I was thinking that it may be possible to integrate the OV pulses and use the resultant voltage to drive a PIN diode ahead of the KiWi. It would then 'self stabilise' at a suitable value of gain reduction. It should be possible to do this wit…
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I've often wondered if it would be useful for the KiWi to be able to present a simple webpage in place of the existing top bar which has limited formating options. Perhaps this could also allow content from other sources to be embedded in the page.…
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Hi John, I wonder if it would be worthwhile bringing the OV indication out to one of the P9 GPIO pins ? It could then be used to drive an external attenuator circuit via a suitable averaging circuit, so that a crude form of AGC could be applied. T…
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Hi Lonecrow, I took a look at your KiWi but I'm not sure what you have connected at the moment. You have 2 very strong BC signals at an indicated frequency of 108.76 (which I assume is 760KHz) and 108.8 (which I assume is 800KHz). So I guess it's…
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Hi Lonecrow, Yes that's correct. I'd suggest keeping the card as an emergency last ditch emergency backup, and buy some additional cards to write to and from. I've found it to be the easiest and most reliable method, even if you have other means …
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Hi Jari, I think it depends upon how much of an overload is occurring. If it is only very short duration and infrequent (just on the edge) then there is a chance that the reading may be OK. But if it is a big signal and practically constant, th…
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Hi Lonecrow, OK that's good so it doesn't look like anything major is broken. I'd suggest that as you are making a lot of changes to the config, it may be a good idea to buy a few decent quality SD cards so that you can backup an image of the whol…
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Hi Lonecrow, That doesn't sound good. If you open up thew new Signal Generator extension and switch it on using the default settings you should see a carrier at 10MHz on the waterfall with a level of about -60dB. Regards, Martin - G8JNJ