KA7U
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- KA7U
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What I do is open the KiwiSDR in a browser instance, by itself, and then minimize it. It continues to play and I can use another browser instance to follow directions or other browser activity. Ron KA7U
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G8JNJ - Martin, I did build a prototype GALI-74 loop amp. https://easyeda.com/doxnairobi/NEW-gali-74-loop-amp I was not very happy with the one I assembled. It seemed the common mode noise was higher than it should have been. I studied that and th…
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The LZ1AQ amp is quite good. If you buy the commercial version it is designed to use either 1 loop or 2 loops. If you use 2 loops the SNR should improve by 3 dB. I have not yet used 2 loops but do plan to soon and I do have a commercial version of t…
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VLF Transmitters at Cutler, Maine, call sign NAA. 44.645,-67.283 covering the peninsula. Ron - KA7U (Image)
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I took a quick look at the log to see what impact TDoA service has on my KiwiSDR's. root@kiwisdr:/var/log# cat user.log |grep -i TDoA |grep -i leaving It appears in my case that most of the usage is from the same user, and while the uses are repeti…
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I experimented with the 180 degree path crossing. It fails everytime. I can hear the station with my receiver, but it won't plot with the other receivers for this station. Still good results with stations not crossing the 180 degree longitude, I'd s…
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I spent time trying to triangulate on Harrold E. Holt - NWC, on 19.8KHz. This station is often heard on my KiwiSDRs, both the active loop and 210' top dipole. I could not find U.S. stations with a decent signal and so I attempted to use a station in…
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John, OK, that did a much nicer result. Very nice! I did check the results and found the triangulation point to be approximately 70 miles north of the transmitter towers. I suppose KiwiSDR location information could be inaccurate and other receptio…
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I found it tough to find 3 stations that could plot WWVB on the map. I don't know if it is because of the type of signal transmitted or what. Ron - KA7U(Image)
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I have success using Firefox on the Kindle Fire. I haven't used it for a few months though. I'll try it out later and see if all is still good. The Silk browser doesn't work with the KiwiSDR on my Kindle however. Ron KA7U
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I did not hear him. I used http://38.86.67.206:8078/ in Indiana and heard K9KFR at 473.50 KHz rst 599 but not KB9RLW. Listening again tonight on the same KiwiSDR. That loop antenna looks very interesting. First quality antenna. Ron KA7U
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I'll listen for him. Curious to see if that multi-turn loop actually gets a signal out. Ron KA7U
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Glenn, I've been experimenting with amplifiers for loop antennas for the KiwiSDR. 3 of the schemes are using Norton amplifiers and one is using a differential amplifier described by LZ1AQ. I lack the technical education to know what I'm doing, but d…
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My dyslexia is manifest... LZ1AQ CHAVDAR LEVKOV, is the designer of this loop amplifier. He is from Bulgaria, not New Zealand. Being unable to edit the post, this correction will need stand as a correction. The loop at http://ka7u.no-ip.org:8074 i…
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OK, now I see what you have. $1 is assigned the file name following the call to wsprctl in the crontab. Haven't used that feature.RonKA7U
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I don't understand this line in the script.cp /root/kiwi.config/$1 /root/kiwi.config/kiwi.json Please tell me what is going on with the $1 variable.RonKA7U
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The KG software is working under wine on linux. I'm having trouble figuring out the buttons on KGFAX, but have it decoding the image. The buttons are ??? instead of text. Probably don't have a Japanese font in the WINE Font library. The KGdgps softw…
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MultiPSK does a fair job with decoding DGPS. https://www.youtube.com/watch?v=-ERcWKIbNhI the author of the software contact is on the attached image.RonKA7U
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I don't think Audacity is designed to us I/Q audio. HDSDR or Dream is what I use to play those files back.RonKA7U
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Martin,Jumping back to your March 10th post on this thread, the DXE RPA-1 circuit, looks to be a simple and inexpensive circuit. I have been comparing it to https://www.okdxf.eu/lankford/Norton-2N5109.pdf. This circuit is much more trouble to build,…
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Martin,This is good information. I have been working with the MFJ design:https://easyeda.com/doxnairobi/gali-74-loop-amp MFJ must have changed the schematic since the review, as there is now 560 ohms to ground on the input. https://www.minicircuits.…
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Martin,http://www.mfjenterprises.com/Downloads/index.php?productid=MFJ-1886&filename=1886 3.8 schematic.jpg&company=mfj The MFJ loop is perhaps the easiest design of the loop amps. The GALI-74 surface mount amp is just fine in this a…
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Matin,It is setup to use CAT5e or CAT6 feed cable, so I'll use a voltage regulator for the power feed pair, and a 100/50 ohm balun to the receiver in the shack. ZL1AQ shows a balun on the power feed pair. I'm not sure why he does that. Maybe you kno…
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Martin,More things to work with. I've discovered http://easyeda.com . Such a deal and easy to use. Now if we could just get them to assemble the boards too. Hi Hi I've attached a prototype image of the ZL1AQ circuit and the modified schematic. Plea…
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Martin,Thank you for your insight and suggestions. Currently I'm working through the parts for the LZ1AQ amp. I'm also curious about the 1000nf capacitors on the antenna input feeds. I'm thinking about a ceramic type. Any recommendations for capaci…
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When a power supply first starts, it doesn't always power on instantly to full output. The KiwiSDR will then fail to complete the boot sequence and go into a loop that doesn't always boot. The solution is to unplug the KiwiSDR, turn on the power sup…
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Martin,This is an interesting circuit.https://www.sv1afn.com/j310preamp.html Nicely made and priced fairly.RonKA7U
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Martin, I changed transistors on the 3 Well good boards and now they keep a low noise floor over a range of voltages. With these transistors the gain starts dropping at about 10 volts. The optimum voltage seems to be 5 volts. Ron KA7U
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Martin,We have decided to build a few of the ZL1AQ amps. Do you still use the MRF581 on your builds? I find the MRF581A available from mouser.com so looks like a good prospect. I read that the 2n2222 are fine for the input pair. Do you use them curr…