KA7U

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KA7U
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  • How to connect via wifi

    The search box in the blue title bar will find lots on the topic. Try wifi kiwisdr in that search.

    This post might be quite useful to you: http://forum.kiwisdr.com/index.php?p=/discussion/comment/9270#Comment_9270

    Wifi isn't supported, but with determination, you will likely get it working.

    Good luck.

    Ron - KA7U

    Sonicresidue
  • first fan died... how long do these things last- what other cooling alternatives ?

    Two of my KiwiSDR units lost the fans finally. So I took them out, blew out the bugs, and put them back together without the fans. Set the two units on edge, with one end elevated 1 1/2" by using a book for a shim. Both of them ran fanless through the summer in the garage. High temperature in there was 95 degrees F this summer and the low is 55 in the winter. ( heated garage). Don't know if the on edge and elevating one end was necessary, but blowing out the bugs was seriously needed. LOL

    They continue to run fine.

    Ron - KA7U

    johnk5mo
  • first fan died... how long do these things last- what other cooling alternatives ?

    I've been peeling off the sticker and dropping some Hoppies gun oil into the little hole. Fans keep on keeping on, albiet a bit noisy when first starting, but then quiet down when up to speed.
    Ron
    KA7U
    k5mo
  • Noise at roughly 60 KHz intervals

    Nick,
    I think 10mbits will run the KiwiSDR. I applied the ethtool utility with your parameters to my KiwiSDR's. The first one was imperceptible change, then the 2nd one showed improvement on the KiwiSDR that has the most interference, then the 3rd one and at that point the SDR with the most interference showed a 6dBm improvement and the interference lines seem to have less density on the spur, as though interfering signals are missing. The KiwiSDR antenna with the worst spurs is about 30 feet from the equipment, the 2nd KiwiSDR antenna is about 250 feet from the equipment, and the 3rd KiwiSDR antenna is about 350 feet from the equipment. So antenna 1, 2, and 3 for future reference. Antenna 3 is a 210' top dipole with 350' of RG213/U underground in conduit, and the KiwiSDR shows the least interference, ka7u.no-ip.org:8073. Antenna 2 is a 120cm copper active loop antenna with 250' of shielded CAT6 4 pair, ka7u.no-ip.org:8074. Antenna 1 is a 100cm coax active loop with 50' of shielded CAT6 4 pair, ka7u.no-ip.org:8075. The dipole is not amplified, the two loops both use the same design of differential amplifier and matching baluns and power supplies.

    When there is no amplifier on the loop antennas the interference is there. With amplification the spurs increase. The differential amplifiers are well balanced for hfe and bias, so common mode signals should be seriously attenuated. Which point has been verified by accident with shielded and unshielded RJ5 connector mismatches. So my theory is most of my spur interference is actually received at the antenna and not common mode. Hence antenna 1 has the greatest interference, and the interference subsides greatly in antenna 2, and is practically nonexistent on antenna 3, the dipole. Now your ethtool parameters have improved the situation even more, but not eliminated it. There remain 3 network switches, one shielded and 2 not shielded, and 2 computers, and 2 monitors, running in the radio shack with the KiwiSDR's.

    I think my next best move is to move antenna 1 out to where antenna 2 is located or nearby, and expect that the interference will be reasonably abated. Replace the unshielded network switches with shielded ones should help too.

    You might find that moving your antenna to the barn and keeping the KiwiSDR where it is, will give the best results.
    Ron
    KA7U
    W1NEJ
  • Wellgood balanced loop amplifier, (Wellbrook clone).

    I have the first Wellgood LNA online ;ka7u.no-ip.org:8074 . It is using a 120cm loop made out of 1" (25mm) soft drawn copper pipe. One of the transistors is running hot and might not last so may not be done with it. Hi Hi. Earlier this evening I was copying Jim Creek down around 24.8KHz quite well, but it is not loud now. Could be the solar storm or it could be the hot transistor. I was also hearing Radio Thailand well at the same time @ 17.630MHz so the frequency range seems to be there. I'll evaluate it to the W6LVP and Hiletgo loops after I figure out what is up with the hot transistor or after I get another board finished. Winding and soldering in the transformers is a serious chore. I substituted parts from George Smart's list to fit the parts in stock at mouser.com and chose to use 2N3866 transistors in the metal can. I'll leave it on the KiwiSDR for a while unless it burns out. 

    This is funny, It occurred to me that this amp with these transistors might not want 9-12vdc to run. So adjusted the voltage for best noise floor with good signal peaks and find that 3vdc is close to optimum. It actually works well at 1.5vdc. How about that? And the transistor seems to be very happy too. I think I'll need to readjust the balancing resistor, although I doubt lowering the voltage will affect that setting.
    Ron
    KA7U
    grant
  • Kiwi BBAI software installation instructions [updated 4-Mar-24]

    Stu,
    You could setup a cron job on the KiwiSDR with crontab -e , see "man crontab" for directions. Examples of commands that would write to the file of your choice below.
    Ron
    KA7U
    root@beaglebone:/home/debian# ct >>temp.log
    root@beaglebone:/home/debian# cat temp.log
    47800
    47000
    47000
    46200
    47800
    root@beaglebone:/home/debian# date >>temp.log
    root@beaglebone:/home/debian# cat temp.log
    47800
    47000
    47000
    46200
    47800
    Thu Feb  6 16:29:34 UTC 2020
    root@beaglebone:/home/debian# 
    Powernumpty
  • DRM Heard

    15325KHz Voice of Russia GRFC loud and clear at grid DN14lf. I was able to decode on all antennas. This video is testing the KiwiSDR using the BeagleBone AI in 4 channel mode. All 4 channels were in use during the test and 2 of them were decoding DRM. It worked but with difficulty and with a rising CPU temperature. But if only one DRM channel, it was very good and is still decoding at S5.
    Ron
    KA7U

    fractional_n
  • New out of box KIWI updating issue. Compiles the same files over and over again. [git fetch issue]

    @Tony1951 , I'm sure you removed the SanDisk card after the initial startup? If you didn't, each time the KiwiSDR restarts it will reload from the SanDisk card.
    Ron
    KA7U
    Tony1951
  • BBG and some PSU problem

    I put these in service on my KiwiSDRs and today the power company had on and off conditions for awhile. I set the time on for a 90 second delay. All the boards came up 90 seconds after the power and were operational. Well worth the time and cost to put in the line.
    Ron
    KA7U
    Powernumpty
  • Kiwi BBAI software installation instructions [updated 4-Mar-24]

    I NEED to get a BBAI.
    Ron
    KA7U
    WA2ZKD