It's crazy how you say parts of building the antenna are not critical but you are so critical of yourself and simple mistakes. I appreciate your content and have learned from those mistakes. KE5JPS 73s
You could increase the length of the reflector by using aluminum tape, or by soldering some copper wire. I thought about building a directional antenna for satellites, but I thought it was necessary to use circular polarization, but with your video you have shown that it is not necessary
Took me 2 attempts to build a QFH antenna. Couldn't been happier. If I had a clear 360 deg horizon, I can get from 0 to 0 deg passes. But I'm starting to aim for 1.7ghz satellite dish now, I'm getting more and more noise on 137mhz.
I saw of your band pass filters and stuff minor in the mail I got the new one from new electric which is the GOES / NOAA no all-in-one premium. Q100 is my real goal going for my ham HB3 in Oct..
I saw of your band pass filters and stuff minor in the mail I got the new one from new electric which is the GOES / NOAA no all-in-one premium. Q100 is my real goal going for my ham HB3 in Oct..
1.7Gzh can be hard as well. I have very strong interference from 4G cell towers on 1.8Ghz. It simply overloads the nooelec goes LNA. I had to buy a cavity filter to solve the issue! But made me lots of headache! So I suggest to look around with a simple antenna and see which frequencies are used around your area.
I build TV antennas very similar to this. Nice work. I’ve used wood, but I prefer PVC boards, because they don’t warp or get went and conduct electricity.
Hi. Thanks to share your video. Build and calculate simple VHF antennal is not difficult today. At the end, the tuning is the most important part. And also detuning, center fréquence , sensitivity to external detuning. I suggest you to learn nano VNA for final adjustment. You can win few dB or more... and you will learn more about radio wave.
Just try to cut outer shield of long USB cable at computer side. It will separate computer ground from RTL-SDR ground. It should reduce spikes at SDR. YT1DL
Have you considered using a USB isolator to isolate your SDR from the computer? At any rate, my guess would be that the longer USB cable was acting as a better antenna at 137 MHz.
That's a great image and the antenna is beautiful too. If you haven't done a video on radiosondes think about that, just as an idea. People, mostly in Europe chase them down and capture them. In the US they are 400MHz and SDR Angel and will decode and plot them on a map. Since they climb to about 35km, they are a low form of spacecraft, well maybe not. If there was a camera on them the sky is black at that level even in the daytime.
Moxon loop is a compact 2-element yagi sort of. Unfortunately I haven't found solid information on Moxon "directors". I built a double Moxon with phasing harness for circular polarization and it's pretty good.
So your question: brass, aluminum, stainless steel? I don't think there's an issue with lightweight aluminum if you run this as a hand-held antenna and keep it indoors when not in use. If you are mounting it full-time outside (on a rotator) then you'll need "anti-seize" from the car repair shops to place over the connections. That all said; congrats on a fantastic LRPT reception with your new antenna! - de W6LHI/G8LHI
After watching this, kind of makes me wonder if I should do a video on the 'portable yagi' I did for 2 meters. I took a bit of inspiration from a video I found some years back, showing how to build a portable yagi antenna. I ended up using a long fiberglass rod, which was a salvaged fishing pole, and some stiff, thin modeling wire. While it is very light, the elements are a bit more on the delicate side. Yours might be heavy, it does look like its built relatively robust. You probably don't have to worry about your elements getting bent out of shape like I have to. If you are thinking to use yours long term, maybe consider mounting it to a camera tripod and putting some counter weight on the back end? (may need to still track by hand for those passes that are directly overhead) Either way, looks like you managed to get yourself some incredible image captures with your setup.
the interference could come from the laptop and/or camera, I don't think it could be anything else. I also think that the antenna can be even better by making a closed dipole! ( here in the Netherlands they also make and use closed dipole for 85MHz WFM ) it is also less sensitive to interference.
Using the calculator (thank you for sharing your measurements), how do you know how long to make the Dipole element segments? I see the location to place it, but I didn't see a length for this element (only the Reflector and Directors). Thank you for this video.
There will be a solution of yagi design that has a shorter reflector like yours and it will be closer to the driven element. In other words the relationship of Yagi reflectors is always longer lengths go with wider spacing, and vica versa. Alternatively, if you have another brass rod, you could make it in two parts, a left part and a right part and use the two rows of the terminal block to join them, overlapping in the center. You might get some front to back performance back as the reflector is key to this particular Yagi parameter. I dont really see any problem using brass in this antenna, materials are not going to make much difference really.
Amazing work, in the 80s we used to use a "crossed dipole" which was like yours a bit and had elements form a cross and made of co-ax phasing harness at the feed point, this improved the gain and removed the 3dB polarisation loss from circular to polar. (on HRPT a 45 degree chunk of perspex I think also alters the polarisation from C to L in front of the antenna) The bloody idiots in the government put LOUD pagers right next to the met band and so this made APT receivers shutdown and totally interfered with the picture. So we went to HRPT in our company...I would use some toroid chokes in the USB cables if sprogs are a problem, I'm so jealous hahaha you get LRPT we waited and waited and finally gave up in the 2001s - I'm gonna do something like this and when it works I will show Thai kids in the local school to maybe inspire them into electronics/computers....great work and now you can put the RX right up the antenna!!! wow
Discord link is expired :( I'd like to join. Anyway interesting theory about RHCP- LHCP. I use a wifi grid antenna for receiving HRPT, and testing it with Elektro L-3 I see significant difference between monting the antenna horizontally or vertically. I don't quite understand why since L3 signal is polarized.
I saw of your band pass filters and stuff minor in the mail I got the new one from new electric which is the GOES / NOAA no all-in-one premium. Q100 is my real goal going for my ham HB3 in Oct..
As a suggestion, you should build a cross yagi to help with the polarization issue. Its what most ham operators use for portable satellite communication.
Yes that would be an ideal solution, but I'd say that unless you can really ensure the phasing harness is good it may just be better to stick with linear. Besides, a design like this can always be upgraded into a cross Yagi in the future. One of my first antennas for 137 MHz was a cross Yagi of the same length as this but it performed worse than this, because I simply couldn't build it properly.
Great video 👌🏻. Can you please make a video showing how to calculate the Yagi Antenna using the calculators that you bring in the video description? Thank you :)
Side passes - 30-60 degrees or so - definitely work better than overhead passes! I get 20 dB @ 45 deg pretty solidly. Overhead I got no more than 13 dB.
i wonder if it's possible to make a handheld, Rx-Only Loop-Yagi, i susspect this would make for a smaller build and possibly have quiet reasonable Rx capabilities...
3D printing isn't necessary. The printed handles I have actually took longer to print than it took me to make the rest of the antenna, and in the video you can see that I often don't even use them and just hold the antenna itself
Maybe in many countries now old television VHF hi gain antennas are lying in the scrap man's yard I know this for sure in Thailand as we have 1gigbit/sec to every home on fibre we use internet TV now and they give us free boxes of 400 chanels of rubbish to watch....old TV antennas have lots of useful bits and if hi gain (many directors) they will have the long pole!
Yeah he came to Switzerland we didn't speak a common language that we had a common person we didn't like him we did everything together worked out hung out cruising around the town he stayed inside son said he had enough of that he didn't go down south or anyting a good dude
Chechen? My first roommate was a PTSD Patient with me from fighting Putin. I was going to go to Ukraine and screw up thier GPS, lazer guidance systems, find where they are hiding (Kraken SDR), dude with what we know from all this a HackRF one, a portapack, a bunch of them, some jetsons with AI vison 360° IR, Optical, UV, Thermal, wow - i hope your on the right side. They killed my Chechen buddy's Brother and Mother. Dude really. And the dude running that place. Us nerds could tweek thier "high tech) wirh fiber optics and "hunting lazers to make nice "false IR, UV etc .. targets or clear flying into a rock wall. amp a GPS spoof so they fire at their own stuff.
On my opinion, best antenna is with good ratio of beam pattern:amplification. This is pretty directional antenna gun :D But out of video I have question for you and for others at this community. I talked with radioamater (who doesn't use SDR but normal transmittor and radio and have license) and read a lot on internet but can't make conclusions. Is it possible to make damage on SDR with Gain too high? Especially when I recording NOAA with 85-90 elevation? I know, that is possible to damage SDR around high RF and powerful transmitters but I think, when gain is using as maxed-out the electronics inside SDR working on same way as it is with lower gain, only some aplifier on circuit making possible to hear low power signal. But, I went on internet and read this article from which is linked with official site rtl-sdr, there also writing about is it better to have some filters which make your SDR dongle secure from overload: www.onesdr.com/2020/01/29/how-not-to-break-your-software-defined-radio-hardware/ And one more question, I did live data wxtoimg passing satellite and i have some a few white horizontal lines. Could be some jamming/interference or is it by live uncompressed data? Because I don't have these lines when I record audio, resample track and put it in the WXtoIMG. I'll be appreciate for response.
American here. Picatinny bit absolutely killed me. Mission accomplished.
I came here to say the same thing 😂
Being from Texas that was great.
It's crazy how you say parts of building the antenna are not critical but you are so critical of yourself and simple mistakes. I appreciate your content and have learned from those mistakes. KE5JPS 73s
You could increase the length of the reflector by using aluminum tape, or by soldering some copper wire. I thought about building a directional antenna for satellites, but I thought it was necessary to use circular polarization, but with your video you have shown that it is not necessary
Took me 2 attempts to build a QFH antenna. Couldn't been happier. If I had a clear 360 deg horizon, I can get from 0 to 0 deg passes. But I'm starting to aim for 1.7ghz satellite dish now, I'm getting more and more noise on 137mhz.
What about a large copper tube Helix like plumbing copper tubing which is pretty easy to manipulate and just soldered together
I saw of your band pass filters and stuff minor in the mail I got the new one from new electric which is the GOES / NOAA no all-in-one premium. Q100 is my real goal going for my ham HB3 in Oct..
I saw of your band pass filters and stuff minor in the mail I got the new one from new electric which is the GOES / NOAA no all-in-one premium. Q100 is my real goal going for my ham HB3 in Oct..
1.7Gzh can be hard as well. I have very strong interference from 4G cell towers on 1.8Ghz. It simply overloads the nooelec goes LNA. I had to buy a cavity filter to solve the issue! But made me lots of headache! So I suggest to look around with a simple antenna and see which frequencies are used around your area.
I build TV antennas very similar to this. Nice work. I’ve used wood, but I prefer PVC boards, because they don’t warp or get went and conduct electricity.
Hi. Thanks to share your video. Build and calculate simple VHF antennal is not difficult today. At the end, the tuning is the most important part. And also detuning, center fréquence , sensitivity to external detuning. I suggest you to learn nano VNA for final adjustment. You can win few dB or more... and you will learn more about radio wave.
Just try to cut outer shield of long USB cable at computer side. It will separate computer ground from RTL-SDR ground. It should reduce spikes at SDR. YT1DL
Nice rig. Are those handles/grips spare parts or 3d printed?
great idea with the terminal blocks!
Have you considered using a USB isolator to isolate your SDR from the computer? At any rate, my guess would be that the longer USB cable was acting as a better antenna at 137 MHz.
That's a great image and the antenna is beautiful too. If you haven't done a video on radiosondes think about that, just as an idea. People, mostly in Europe chase them down and capture them. In the US they are 400MHz and SDR Angel and will decode and plot them on a map. Since they climb to about 35km, they are a low form of spacecraft, well maybe not. If there was a camera on them the sky is black at that level even in the daytime.
Moxon loop is a compact 2-element yagi sort of. Unfortunately I haven't found solid information on Moxon "directors". I built a double Moxon with phasing harness for circular polarization and it's pretty good.
So your question: brass, aluminum, stainless steel? I don't think there's an issue with lightweight aluminum if you run this as a hand-held antenna and keep it indoors when not in use. If you are mounting it full-time outside (on a rotator) then you'll need "anti-seize" from the car repair shops to place over the connections. That all said; congrats on a fantastic LRPT reception with your new antenna! - de W6LHI/G8LHI
After watching this, kind of makes me wonder if I should do a video on the 'portable yagi' I did for 2 meters. I took a bit of inspiration from a video I found some years back, showing how to build a portable yagi antenna. I ended up using a long fiberglass rod, which was a salvaged fishing pole, and some stiff, thin modeling wire. While it is very light, the elements are a bit more on the delicate side. Yours might be heavy, it does look like its built relatively robust. You probably don't have to worry about your elements getting bent out of shape like I have to. If you are thinking to use yours long term, maybe consider mounting it to a camera tripod and putting some counter weight on the back end? (may need to still track by hand for those passes that are directly overhead) Either way, looks like you managed to get yourself some incredible image captures with your setup.
Sweet - picture ( do you ever worry that you may look like shooting at the airplanes?) 😂
the interference could come from the laptop and/or camera, I don't think it could be anything else.
I also think that the antenna can be even better by making a closed dipole!
( here in the Netherlands they also make and use closed dipole for 85MHz WFM )
it is also less sensitive to interference.
Using the calculator (thank you for sharing your measurements), how do you know how long to make the Dipole element segments? I see the location to place it, but I didn't see a length for this element (only the Reflector and Directors). Thank you for this video.
Those USB cables can be noisy. I"ve a similar yagi tuned for 145.90 MHz but it will probably work well enough for this.
Try moving the SDR to behind the reflector, the SDR has a local oscillator that could be contributing to the high noise floor.
There will be a solution of yagi design that has a shorter reflector like yours and it will be closer to the driven element. In other words the relationship of Yagi reflectors is always longer lengths go with wider spacing, and vica versa. Alternatively, if you have another brass rod, you could make it in two parts, a left part and a right part and use the two rows of the terminal block to join them, overlapping in the center. You might get some front to back performance back as the reflector is key to this particular Yagi parameter. I dont really see any problem using brass in this antenna, materials are not going to make much difference really.
Amazing work, in the 80s we used to use a "crossed dipole" which was like yours a bit and had elements form a cross and made of co-ax phasing harness at the feed point, this improved the gain and removed the 3dB polarisation loss from circular to polar. (on HRPT a 45 degree chunk of perspex I think also alters the polarisation from C to L in front of the antenna) The bloody idiots in the government put LOUD pagers right next to the met band and so this made APT receivers shutdown and totally interfered with the picture. So we went to HRPT in our company...I would use some toroid chokes in the USB cables if sprogs are a problem, I'm so jealous hahaha you get LRPT we waited and waited and finally gave up in the 2001s - I'm gonna do something like this and when it works I will show Thai kids in the local school to maybe inspire them into electronics/computers....great work and now you can put the RX right up the antenna!!! wow
Thanks for sharing your experience. I would like to know what software you are using (besides sir) and does it decode the image in real time?
I am using aptdec for APT, satdump and LeanHRPT for LRPT. I don't decode in real time
Discord link is expired :( I'd like to join.
Anyway interesting theory about RHCP- LHCP. I use a wifi grid antenna for receiving HRPT, and testing it with Elektro L-3 I see significant difference between monting the antenna horizontally or vertically. I don't quite understand why since L3 signal is polarized.
I saw of your band pass filters and stuff minor in the mail I got the new one from new electric which is the GOES / NOAA no all-in-one premium. Q100 is my real goal going for my ham HB3 in Oct..
As a suggestion, you should build a cross yagi to help with the polarization issue. Its what most ham operators use for portable satellite communication.
Yes that would be an ideal solution, but I'd say that unless you can really ensure the phasing harness is good it may just be better to stick with linear. Besides, a design like this can always be upgraded into a cross Yagi in the future. One of my first antennas for 137 MHz was a cross Yagi of the same length as this but it performed worse than this, because I simply couldn't build it properly.
No man take your good where you got it man it was awesome image you deserve kudos you get five stars A+ awesome work
Great video 👌🏻. Can you please make a video showing how to calculate the Yagi Antenna using the calculators that you bring in the video description? Thank you :)
Side passes - 30-60 degrees or so - definitely work better than overhead passes! I get 20 dB @ 45 deg pretty solidly. Overhead I got no more than 13 dB.
bahahahaha, picatinny rail, very nice touch for the 'mericans
I bet the powered USB repeater near the SDR is causing interference... Oh, you say that in the video.. lol. I wasn't there yet
Keep up the great work!
Super damn awesome dude
Discord link už pravdepodobne nefunguje, vedel by si dať nový?
i wonder if it's possible to make a handheld, Rx-Only Loop-Yagi, i susspect this would make for a smaller build and possibly have quiet reasonable Rx capabilities...
You dont have sawbird for 127 mhz? Also how much you pay for copper rods?
I'd like to build this antenna too. Are there 3d printable files available so I can make the antenna easier?
3D printing isn't necessary. The printed handles I have actually took longer to print than it took me to make the rest of the antenna, and in the video you can see that I often don't even use them and just hold the antenna itself
what do you use to track satellites?
the same thing happened to me a few days ago. wondered why i wasnt recieving lrpt at 137.1, then i realized it had changed.
And now it's back to 137.100
Great video with an awesome self reflection (not agreeing with the reflection btw ;-))
Could it could be the day we're approaching the maximum solar cycle I mean they could just get the ionosphere and space weather
Nice!
What about a large copper tube Helix like plumbing copper tubing which is pretty easy to manipulate and just soldered together
I don't think that would reduce the weight for portability. Copper pipe would be awesome for permanently mounted antennas.
Dobrá práce !
Maybe in many countries now old television VHF hi gain antennas are lying in the scrap man's yard I know this for sure in Thailand as we have 1gigbit/sec to every home on fibre we use internet TV now and they give us free boxes of 400 chanels of rubbish to watch....old TV antennas have lots of useful bits and if hi gain (many directors) they will have the long pole!
3 days the signal is distorted at 137 MHz, no decoding.
It switched to a different coding, satdump has yet to be updated
add ferrites. Everywhere.
also,I would build a tripod, but thats me
Yeah he came to Switzerland we didn't speak a common language that we had a common person we didn't like him we did everything together worked out hung out cruising around the town he stayed inside son said he had enough of that he didn't go down south or anyting a good dude
picatinny rail , lulz
Chechen? My first roommate was a PTSD Patient with me from fighting Putin. I was going to go to Ukraine and screw up thier GPS, lazer guidance systems, find where they are hiding (Kraken SDR), dude with what we know from all this a HackRF one, a portapack, a bunch of them, some jetsons with AI vison 360° IR, Optical, UV, Thermal, wow - i hope your on the right side. They killed my Chechen buddy's Brother and Mother. Dude really. And the dude running that place. Us nerds could tweek thier "high tech) wirh fiber optics and "hunting lazers to make nice "false IR, UV etc .. targets or clear flying into a rock wall. amp a GPS spoof so they fire at their own stuff.
On my opinion, best antenna is with good ratio of beam pattern:amplification. This is pretty directional antenna gun :D
But out of video I have question for you and for others at this community. I talked with radioamater (who doesn't use SDR but normal transmittor and radio and have license) and read a lot on internet but can't make conclusions. Is it possible to make damage on SDR with Gain too high? Especially when I recording NOAA with 85-90 elevation? I know, that is possible to damage SDR around high RF and powerful transmitters but I think, when gain is using as maxed-out the electronics inside SDR working on same way as it is with lower gain, only some aplifier on circuit making possible to hear low power signal. But, I went on internet and read this article from which is linked with official site rtl-sdr, there also writing about is it better to have some filters which make your SDR dongle secure from overload: www.onesdr.com/2020/01/29/how-not-to-break-your-software-defined-radio-hardware/
And one more question, I did live data wxtoimg passing satellite and i have some a few white horizontal lines. Could be some jamming/interference or is it by live uncompressed data? Because I don't have these lines when I record audio, resample track and put it in the WXtoIMG.
I'll be appreciate for response.