njc

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njc
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  • Could probably bias it with one kiwi and use an AC-coupled splitter to the other -- however it might just be easier to deploy two GPS antennas. They are pretty small...
  • Slump is when the voltage sags. If you have a bench supply or something that can provide a solid 5V @ several amps, try that first to rule out a PS issue.
    in wont turn on? Comment by njc March 22
  • There should be LEDs flashing on the Beagle. Measure the V at the board connector itself or the header pins. Try powering the Beagle with the kiwi removed.
    in wont turn on? Comment by njc March 22
  • @Nate_R Interesting, thanks. On my v1 the GPS antenna on a non-metal surface didn't work well at all. I prefer the magnet since mine is outside in the elements. Impressive setup @Tremolat ! Do the solar/PV systems cause you much RFI?
  • That will work fine for the GPS antenna (so long as it isn't stainless or aluminum - the magnet needs to stick). I'm using an even smaller bracket I found laying around.
  • Cool project, Todd. Some good beverage info is here: http://www.w8ji.com/beverages.htm I used a small binocular core with 2 turns on the kiwi side and 6 turns on the beverage side for 9:1 ratio. A "turn" is through BOTH holes by the way…
  • 75 ohm should be fine. You aren't matched 0-30MHz anyway, though a really long run could have some appreciable mismatch loss. As far as heat, my Gen1 kiwi lives in a sealed metal box out in my shed. I've never had a problem with it shutting down or…
  • Log analysis is a great idea. When I was troubleshooting, I ran this script as a cron job every 5 min. Perhaps it will be helpful to you. In the crontab I piped the output to a log file, e.g.: crontab -e  */5 * * * * /root/wifi_connect.sh >>…
  • Definitely make sure it's not a signal issue. You could also try this: cd /opt/scripts/tools ./update_kernel.sh Reboot and then see if it's any different. More info and things to try here: https://learn.adafruit.com/setting-up-wifi-with-beaglebon…
  • Hi Eric, Try it with the wired LAN disconnected and see if it connects on its own. I seem to remember this issue before, though I think I must have done something to make it connect even when the wired is present. Nick
  • Hi @eric_j_johnson . I think HB9TMC is right with the package that is missing. I remember when I was getting the MT7601 working I had to install the headers. Nick
  • I thought the "gold standard" (at least on HF) was S9 = 50μV (-73dBm @ 50-ohms) and an "S-unit" was 6dB. In the context of the Kiwi, it's unlikely the antenna is going to be a nice 50+j0 on every frequency from 0-30MHz (unless i…
    in S meter Comment by njc December 2023
  • FWIW, this is the Google translate of the first image in the OP: https://forum.kiwisdr.com/uploads/340/QNVSDGEUTUP9.jpg
  • You've clearly done your homework! You've got me thinking about possibly modifying mine (or making a new one). I'm not using mine on the kiwi though, I'm using it as an RX2 on my HF rig. So it kind of does double duty depending on what I need: L…
  • Wow, Martin. Thanks for all of the great insights and advice!
  • If cost is the concern, I've had good results with this loop amplifier: https://casarain.com/products/lamb-1b-hf-receiving-loop-amplifier It's only $20 but of course you still need an enclosure for it to keep it dry. For the loop itself, I used 1…
  • Thanks for the input and suggestions, guys. My box is metal and it is completely sealed. I expected some issues with this configuration in the summertime but haven't really experienced that. Stu, great minds think alike! Over the weekend when I …
  • Greetings, Stu! I'll answer/comment on your questions in the order you presented them: It's located in my shed and it's pretty close to the AP, maybe 100ft, and the AP reports full strength when it's connected. I do not know whether it's booted and …
  • @ok1vaw Sorry for the late reply. Yes, mine is running that added CSS: http://kiwisdr.njctech.com
  • If it's your kiwiSDR, try adding this at the bottom of the "Webpage" tab in the admin portal: <script type="text/javascript"> ext_set_controls_width_height = function(e, t) {   if (e > window.innerWidth) {     e = window…
  • Also, he's right about static charge buildup. In my case, the beverage antenna is transformer coupled so there is no DC but other antennas can and will have static charges from rain/snow/passing storms/wind/alien spacecraft/etc.
  • @jks out of curiosity, what is the part number of the TVS used? It looks like the absolute max input limits on the LTC6401-20 ADC is specified as a max current of 10mA. If I'm reading the datasheet right the lowest input Z is 170 ohms. At 3.3V …
  • Indeed they do, but those problems do not result in blown hardware. I think if we are going to be TX-ing in proximity to our kiwisdrs, we have to accept that during tx there will be distortion/overload/mixing products and that the kiwi will probabl…
  • 1N4148 diodes in parallel facing opposite directions across the input. The term "back-to-back" has always been a pet peeve since it incorrectly describes what we are trying to do. You want to limit the voltage to Vf in both directions. Y…
  • Probably just a typo - but the correct port is 8073.
  • All valid concerns for sure. I also have constant attacks on my firewall, but I'm running mail and other services so I'm more of a target. For months I've had continuous attacks from bot nets. Same vectors, different IP each time. Bastards. Anyw…
  • What could be the purpose of using multiple channels to monitor CHU on a 1-2+ second delay?
  • Ben, Since it seems like the problem is under the FPGA, I would try a reflow operation. No guarantees it would work but not much to lose either. If you have access to a heat gun capable of 500°F or so you could try it. Use kapton tape over the part…
  • I agree, those caps are not needed. The choke probably be could be omitted (shorted across) too...
  • I had assumed that 5VE (5VEXT) would be tied somewhere to 5V but apparently not. So my best guess is 5VE feeds power from the kiwi barrel connector to the BBG, then the BBG would provide the other power rails (including 5V) to the kiwi. When you d…