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Today's v1.694 update is hopefully a working version of the failed v1.691,692 release of a few days ago.
See the first post of the "v1.694" thread below for the CHANGE_LOG notes.
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Moving my Kiwi-2 to the cabin in the woods this weekend... March 2024

I've been testing the Kiwi-2 at home for the last few weeks and I'm ready to move it to my place at Lake Merwin in Washington State.

It's been worked pretty good at the home location near Vancouver, Washington. Been able to null out noise with the cheap MLA-30+ loop I have at home.

I now have internet via a 5gHz private link from across the lake that has proven to be fast.... not cheap! Had to buy some Ubiquity equipment and will have a monthly charge, but seems to be fast. I'm averaging 50-60 Mbps down and 20-26 Mbps up. Should this do it?

In preparation, I designed and 3D printed a cooling 'hat' for the Kiwi2 that will have an AC 80mm fan. I'm a bit worried about summer heat in my building when not there with AC on. Might add a mechanical temperature switch to shut things down above whatever inside air temp I need to? Curious what others are finding necessary? Thought about something mechanical to not create any more noise.

Antenna to start will be a W6LVP loop although I have acres to experiment this summer and ultimately would like to build some sort of antenna switch to further experiment.

I have also have a power conditioner and a 1500va/1000w UPS I'll put in place. Winter brown-outs are common with the power system up there. Wifi will reboot but I don't want to have anything go wrong with the Beagle Bone.

Anyways... Hoping to have it running Saturday night from its permanent location at 1260' just south of Mt. St. Helen's above Lake Merwin. Hoping it's quiet and useful from there.

Any other experiences or considerations I should know?

Thanks in advance!!!

73, KB7RQQ


  • Hello,

    If you have hectares of land, don't hesitate to place your antennas as far away from buildings as possible, in clear areas.

    Here in Tremolat in the southwest of France, I have two Kiwi receivers.

    The first antenna (mini-Whip) is 55 meters from the receiver. But it's not far enough. The second antenna (one vertical 11 meters) is at 251 meters (823 feet), slightly elevated, well clear.

    I designed a well-ventilated case. Each of the KiwiSDRs has its own 2U 19-inch box, in a 43U computer bay. the 5V 3A + 15V 1A power supply is linear. The KiwiSDR case is not grounded, following John's advice.

    The network cable is ordinary. There is a large lightning arrester on the antenna cable.

    I have no parasites, yet there are plenty of noise sources (2 x 6KW regulation inverters, 15KW+3KW photovoltaic inverters, computer servers, routers and ethernet switches).

    The cables for the two GPS antennas are 30 meters long, because you have to go to the top of the building and the Kiwis are on the ground floor.

    Best regards, Philippe

  • Here is one of the two boxes that accommodates the KiwiSDR.

  • Beware of UPS's, some are VERY noisy.

    If you want to provide support if the mains fails, consider using a battery bank and powering the equipment directly.



  • Thanks guys! I currently have 100 feet of RG174 +the 25' already attached to the antenna. I'll get going with that and test. Then plan improvements for subsequent trips. Hoping the UPS is quiet.... but we'll see. Thank you both for the info.

  • For the 251 meter cable, I chose satellite TV cable, with 5 layers of shielding. It's 75 ohms, it doesn't matter. This cable is not expensive. On the other hand, I buried it 250 meters, 30-40 cm underground, in a 40mm sheath.

    The RG 174 is too weak. You will see considerable losses and important penetration of parasites.

  • I do have a big spool of 75ohm. I was thinking it may not work well with my active loop? not sure.... I'd guess being a receive antenna it may not matter. I'm taking the 75ohm with me... I belieive it's about 200' on the spool. I'll try and get a wire up to experiment with too. I've sort of blown the 'budget' to the point where the XYL might notice and start asking questions... So improvements will be made in the coming months. I'm currently using 75ohm for my HF loop-on-the-ground at home.

    Thanks for including pictures of your install. This feedback all helps. Nice thing is i can walk around with my laptop and simply see what is happening while I'm there and find the quietest place I can for now. It has to be better than my home location.

  • 75 Ohm good for all HF RX

  • The isolated pylon (a height of 11 meters) :

    High impedance to low impedance transformer, and 20 dB amplifier to compensate for the loss of 251 meters of 75 ohm cables. 20 dB is too much. I have to add 7 dB of attenuation upon arrival in the KiwiSDR 2.

    The amplifier also serves to stabilize the impedance at 75 ohms at the output before entering the coaxial cable log, from 100kHz to 30 MHz.

    Without the amplifier, the impedance variation at the transformer output would be too great. This would not allow such a long cable to be supplied with 75 ohms.

  • njcnjc
    edited March 21

    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 misbehaving in the heat. It gets close to 100F here and ambient in the shed would be higher. There's no active cooling but the metal box may extract some heat. I previously had issues with cold but that turned out to be a wifi dongle issue.

    If you have all of that land, and I assume it's wooded, you could try Beverage antennas. Mine is on a 190m long west-facing Beverage (9:1 voltage transformer at the rx) and it works really well, even in off-directions. 160m, AM BCB, and VLF are pretty phenomenal at night but other bands come in great too. You could rig up a few of them with antenna switching. It would be neat to see what you'd get from the West coast.

    One other note: In my little transformer box I also added two 1N4148 diodes for protection. Between those and perhaps that the kiwi has no DC connection to the antenna I've not had any failures due to lightning or snow static, etc.

    I'm looking forward to trying out your kiwi!

  • Thanks for sharing, interested to check yours out when it's up and running!

    I'll be doing something similar with mine. Been getting acquainted with it at my main QTH, and then will move it to my cabin in NE Wisconsin later this spring, where it will live in my shed there. I need to trench and bury power to the shed first, and get some sort of antenna up for now....likely a loop of some sort.

    The 5ghz link you have should MORE than do it speed wise, assuming latency isn't too bad. I have 0.6 mbps upload from my cabin..... This is part of why I got a Kiwi, it can handle lower bandwidths.

    I brought my KiwiSDR2 there last weekend to make sure I had the router settings correct, that the wifi would reach the shed reliably enough, etc.... looking good so far. I need to get my power supply in a case, and then as soon as the ground is reliably thawed, I'll be digging a trench. :-)



  • @Tremolat That is a SERIOUS installation. Very impressive. I took the Kiwi down last night and have everything loaded in my truck. Heading up after work to start the process tonight. It's about a 2-hour drive is all. I do need to come in to work for a bit tomorrow.... then back up there to keep going with antenna work. I currently have an MLA-30 antenna up for my portables. I will hopefully get it running, all the network stuff figured out, and connected to that antenna tonight. Then I can watch while "working" tomorrow.

    Saturday, I'll do some real antenna work and find the 'quiet' as best I can. I have some Amazon LED light strings on my deck that are absolutely terrible with noise. Those will be headed for the bin and I'll figure something else out for that.

    Not too fancy right now.. but I will get some pictures of the install.

    Todd KB7RQQ

  • @njc Thanks for that info too. I do have a beverage transformer that I tried before I did the loop on ground for HF and spun my own transformer. I need to find the notes on the beverage transformer I have. Believe I got it from DX Engineering. I remember you need to terminate those to ground with a resister. I'll see if I can find it online here and grab the notes.

  • Cool project, Todd.

    Some good beverage info is here:

    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. You can test it with a resistor and an impedance analyzer (450 ohm R will read as 50-ohm on the pri).

    At the kiwi end, one leg of the secondary of the transformer goes to the beverage, the other to ground (a couple of 4+ft rods). The far end of the antenna is terminated to ground through a 560-ohm 1W or 2W carbon R (down to ground rods). I used steel electric fence wire (strong, cheap). I do have to check it every so often for trees falling on it etc.

    If you do a beverage let me suggest this, especially since it will be at a remote location. To limit breakage, leave some significant slack in the wire, like 3-4 feet. Then pull it tight and twist it leaving a decent radius loop. I realize this description is not great, but the idea is to have this configuration "give out" if excess strain is placed on the wire. Something kind of like this:

    If the two straight parts are pulled enough the loop will give out and protect the wire from breaking (if a tree fell on it). Incidentally, neither this loop, nor a tree on your antenna will affect its performance all that much - you might not even notice!

    Nick W1NJC

  • @njc Awesome... I have some binocular cores from my Beverage-on-the-ground project at home.... that I'm not too impressed with BTW. I added a low-noise eBay amplifier and it helped a bit. I think these are 2:6 windings but I have extra parts. Found these pics on my laptop of that project.

  • Sheez! I didn't even consider the GPS antenna... luckily I'm at work. Found this, bent it in a vice and am having one of the guys powder coat it black. I'll attach this to the cabin and it will work for now. 😂

  • 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.

  • @njc Yep... Mild steel test panels that we use for coatings testing. This is a bit big but will get it out past the metal roofing.

  • @kb7rqq, Todd, thank you very much, I'm trying to do the best. There aren't many KiwiSDRs in the area where I live. there are large natural spaces, rivers, forests and meadows. My closest neighbor (500 meters away) is American (Massachusetts). He chose to come and live in France Perigord. He raises horses. He uses electric fences which cause broadband noise (clack, clack, clack). It's not that important.

    Here, we have two sources of electricity, a large hydroelectric plant 5 km away and photovoltaic installations.

    I installed a small private photovoltaic production field which allows me to make substantial savings. It produces between 30 and 50 KWh per day, with a peak power of 12KW. The two KiwiSDR receivers are powered by the sun, during the day.

    For the moment, I do not store electricity. I only have 3 KWh of battery in case of backup, so as not to have all the computer servers suddenly shut down.

    Ultimately, I plan to store the electricity in large buried tops (under the form of kinetic energy). These would be concrete-cement tops. This is a project under study.

    Good luck with your achievement. This interests me and I will follow it carefully.

  • edited March 21

    njc, I don't think there's a magnet in the KiwiSDR2 GPS antenna...seems to just be adhesive.

    I assume a bit of metal will still help reception, though.



  • @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?

  • The receiver is up! Definitely better than home. Will continue to work on improvements through the weekend.... and see what night time brings.

  • Sheez.. got up there last night and had bought some SMA extension cables of Amazon. It's the small RG174 male to female. Went to hook them up and the pins were reversed.... meaning the female threaded end was missing the pin, but the male threaded end had the pin. I thought I might be able to pull the pin and insert it in the other end but didn't have any needle-nose pliers. Being a good radio nerd, I had some RG8 with PL259's and adaptors in the box so it's online with that until amazon shows up today with the correct cable. I will run better stuff once I settle on where/what the antenna will be.

    Also... took my impact drill instead of my drill so didn't have a chuck on it for the drill bits. Luckily, my neighbor was there. He didn't have a drill but had bits that had the arbor so I was able to make that work.

    No matter how much I meticulously plan something.. I manage to mess it up somehow.

    But it is an improvement over the home location and will continue to get better.

    Thanks for all the input and ideas.

    Todd KB7RQQ

  • Yep, exactly, it's an improvement and will get better over time as you tweak/change things. I've had to internalize that a bit myself. :-)

    Sounding a bit weak overall right now, but not too much RFI noise! So I assume it will get better with a better antenna setup. I was able to hear myself on FT4 this morning on 20M... from my 25w in my attic dipole in Wisconsin.



  • I should I add I TOTALLY hear you on having the right tools and things with you! Over the years of developing a site from only trees to building a cabin on it, I've learned you can't anticipate all the tool needs, and neighbors that are full time can be a real blessing!


  • The antenna is currently a W6LVP loop which is better suited for the home noisy environment. I'll play with some wire when I get back up there tonight and over the weekend. Wanted to get all the drilling, stapling, and other violent stuff done before the XYL gets there 😉 so last night was a success as far as that goes.

  • @NJC : yes, the solar panels are bryant on radio frequencies, because of the inverter switching system. Now, I filter all this noise with appropriate filters, on the solar panel side and on the sector grid side. In addition all high voltage cables (450 vdc and 400 vac) are buried and the inverters are in metal bays. As a result, no more parasites. Between the Kiwisdr 2 antenna and the photovoltaic panels, there is a distance of 450 meters.

    @kb7rqq : you are progressing well. There is a lot of background noise across the entire spectrum from 30K to 30MHz. Perhaps you have an active antenna that has a noisy preamplifier? In terms of sensitivity, you can see on this track.

    interesting. Brest regards, Philippe

  • @Tremolat Yes. It is an amplified loop at the moment.

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