How To Build A V Dipole For Receiving Weather Satellites 

You’re very welcome! Thanks for watching 🙏

@@TechMindsOfficial i would really love to see how u install all the bits to get it to work to gather

Was a video ever created demonstrating the setup?

Thank you for sharing. I plan to make a QFH in the near future. 👌

I agree about Meteor not needing Doppler correction from software, but for NOAA APT it is needed.

@@TechMindsOfficial If what you are doing works for you, then that's fine, but I will refer you to thread(s) found on r/amateursatellites and/or r/RTLSDR where DerekCZ (the guy that did NEC work with the radiation pattern optimized V-Dipole with the reflector) says the same thing as me, about not needing it for use with WXtoIMG. I don't use it any more and I've been seeing better results since I stopped using it. The WXtoImg documentation should also be helpful. Look to the PLL section for what I am talking about with integrated doppler correction in AF. You have to calibrate the PLL, but after you do you should have clean doppler correction in the AF. If you do it externally quickly enough with the PLL off, the results should be the same. It looks to me like your external correction is fast enough here, but my correction using Orbitron was not fast enough and resulted in the shifting described in some of these reddit posts. Doppler and Sample Rate Related Thread(s): 1) www.reddit.com/r/RTLSDR/comments/gycdye/i_dont_know_why_my_picture_came_out_like_this/ 2) www.reddit.com/r/RTLSDR/comments/2z1dmq/wxtoimg_why_is_noaa_image_shifted_what_to_do/ 3) www.reddit.com/r/RTLSDR/comments/67zlzb/what_is_causing_this_horizontal_distortionlines/ 4) www.reddit.com/r/RTLSDR/comments/bbcf1g/think_that_youre_getting_bad_images_from_noaa_apt/ PLL correction calibration: leshamilton.co.uk/wxtoimg.htm (ctrl-F PLL)

@@TechMindsOfficial On another note, you should definitely check out DerekCZ's work on a radiation pattern optimizing reflector for the V-Dipole. There is some cool NEC stuff going on, and it appears to get pretty good results after adding the reflector or optimizing the ground distance. www.reddit.com/r/amateursatellites/comments/cnnjjm/how_i_came_up_with_my_current_vdipole_design_and/

Thanks for sharing Robert, I’ll definitely got it a look. I really need to get myself into Reddit, something that I havnt done yet believe it or not. Thank for watching 🙏

Thanks for the advice Florian! I did wonder if the “locked” should be solid or flashing but it appeared to be flashing. Yes, I guess it doesn’t need the frequency tracking when being controlled by software. I will definitely give Meteor another go because the images I’ve seen look incredibly good quality. Thanks for watching my videos 🙏

@@TechMindsOfficial "locked" should be solid red. And, yes, do not track Meteor's frequency will remove most of the missing lines.

Excellent! I’ll definitely be going through these home built antennas and testing them. Not every one can afford commercial antennas and if we can build something out of cheap parts, that actually works, then it’s a win win! Do you have a link to some plans you could share with us please?

@@TechMindsOfficial for antenna dimensions I used a Moxon calculator (tippete.net/cgi-bin/moxgen.pl ) , for wiring i used (on5au.be/content/a10/vhf/ms2.html ) and all was made from [Cu] water pipes (15mm)

V dipole has been proven to be better than any turnstile, turnstile is trash

Thank! I did create the video, it’s the video after this one :)

Thanks for the comment and for watching. I have quite a few videos on receiving NOAA weather satellites. Please take a look through my older videos, and if you find anything missing please let me know.

Absolutely! Thanks..!

Another subscriber has just informed me my Meteor decode could of been bad because I left the “tracking” ticked on the demodulator. I guess the tracking is not needed because GPredict was already setting the frequency. I will be investigating this further and make some more videos on this subject. Thanks for watching 🙏

You need to download wxtoimg beta

I was actually trying to find some of these “rabbit ears” but I couldn’t find any long enough. But yes, please try it and let me know how well they work! 👌

@@TechMindsOfficial Search ebay for "Black Lightweight Telescopic Antenna for Portable FM Radio Scanner VHF TV 300 Ω" There's a few different types on there. The most basic are just a set of telescopic rods in a peg mount thing that clips into a hole in the case on the back of a lot of old CRT TV's. They usually have 300 ohm ribbon cable but that can be changed easily enough. I'll get mine up after work and see what happens

Thanks Ben I’ll take a look 👌🙏

Non magnetic for sure 👍

I’ve had a few people ask so I will definately do a software setup video real soon :) thanks for watching

I'm pretty sure I purchased them from my local DIY store (Wickes in the UK).

Well, I will be able to answer that over the coming weeks as I plan to also build a crossed dipole and QFH. I had read somewhere that the V Dipole is on par with a QFH, but without testing myself I can’t be sure.

@@TechMindsOfficial I'll be looking forward to it then

@@TechMindsOfficial I'd be very interested in seeing the QFH plans you use and exactly how you bend the pipe. Would love to see the QFH you build connected to an antenna analyzer so we can see the frequency response and SWR.

Stripped back the coax to separate the Center and outer, then connected them into the choc bloc.

@Tech Minds Thanks!

Thanks for the video; I was modelling something like this, out of curiosity, only the other day! I suggest that coiling several turns of the co-ax, at the feedpoint, would be a good idea, to form a (crude) choke-balun, otherwise the outer of the co-ax becomes part of the antenna.

Absolutely, I do plan to make one soon and document the build process. Thanks 🙏

@@TechMindsOfficial good job sir

I think you’ll be okay, just not too close to the J-Pole and you’ll be fine. Let me know how you get on 👌

@@TechMindsOfficial sure thing. I'll source a mast-clamp and the rods, then post it on my blog giving you the rightful credit ! 73's M7ALU (Edit 1/6 - parts ordered, should be good for the weekend)

Thanks for the comment and information. I didn’t show this in the video but I did put this antenna on a network Analyzer and it was perfectly balanced around the desired frequencies. So for me the length of the rods were just right. May I ask why I would need to change the V direction in the evenings as the radiation pattern for this type of antenna is supposed to be designed for a zero pattern, so there should be no nulls.

@@TechMindsOfficial copy & paste from M Fathurahman found on iopscience.iop.org: With the V dipole antenna in the horizontal direction, the radiation pattern will be directed to the sky with a pattern of zeros (0). This form is very optimal for receiving satellite signals that are in the direction of the front, side and top of the antenna. Because the direction of the NOAA satellite orbit from north to south or vice versa, the antenna is sufficiently directed towards the south or north. With the V dipole antenna in the horizontal direction, the radiation pattern will be directed to the sky with a pattern of zeros (0). This form is very optimal for receiving satellite signals that are in the direction of the front, side and top of the antenna. Because the direction of the NOAA satellite orbit from north to south or vice versa, the antenna is sufficiently directed towards the south or north.

@@TechMindsOfficial simple explanation: for high elevation passes it doesn't matter. If the satellite is low above the horizon, pointing the V to it helps a lot.

Roughly 2cm, but keep it as short as possible but enough to poke into the choc block. The bend is included in the overall length. The size of the bend part will depend on how big the choc block you use.

I tested using steel, unfortunately it wasn’t stainless and it’s gone all rusty now. I havnt personally tried other materials, but copper, stainless steel and aluminium should all work similar.

Lol nope, I’m from West London :) Well, in the countryside :)

The whole point of the antenna being higher is to clear the surrounding obstructions. If you was say, in a field, with no obstructions 360 degrees, then of course, the antenna could be low to the ground, but in suburban areas having the antenna higher would hopefully clear some of the obstructions and provide a signal at a lower angle.

No, a balun is not needed as this antenna is tuned, which theoretically means the impedance at feed point would be near 50ohm. So, no need for a balun. However, experimentation is always fun!

Good question, but I followed the guide for building this. I would assume it is because this is not a straight dipole, it’s a V dipole. But without modelling it in software I can’t be sure. Either way, it was resonant where it needed to be.

Fixed, just need to point the open side north and the side where the antennae meet south, also make sure your coax cables' screen is properly touching your adapter!

At the start of the video the second image shows the antenna looking down on it. So the point, where the two legs meet point north

Thanks, now I get it! Can it be used for TX? I'm looking for a circular polarized antenna to send aprs packets to ISS without pointing to it.

Mines gone rusty very quickly :-(

@@TechMindsOfficial What exactly? The aluminum or the Choc board? Is there a possibility of some damage the any of the components outdoors from rain? Also can i use Copper? Here in Europe its pretty hard to find aluminum and amazon delivery is very expensive and takes a while!

Have you tried the Beta version instead?