Let's build a 6 lobe circular polarized 5.8GHz antenna
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- čas přidán 8. 09. 2024
- This video is about building a six lobe circular polarized 5.8GHz antenna for FPV use.
Link to STL files: www.thingiverse...
RG402: www.ebay.com/it...
Copper wire: www.ebay.com/it...
SMA connectors: www.ebay.com/it...
nice video, those fixtures look pretty handy. Just wanted to say that after building several antenna using solid copper wire I switched to MIG wire about a year ago and it is far more durable over time AND I think it is easier to work with because once you bend a shape it holds that shape far better than copper. If you align the tips to the center element of the wire carefully, soldering all the tips to the center wire is simple.
Another tip Id toss in is that when you are using the semi ridged RG402 you can make custom bends in the cable which last a long time by stripping off some insulation and just adding a coat of solder where you bend the cable. Once the solder goes solid that shape is now part of the cable. I use this to make a 90° bend just after the SMA connector instead of using a right angle connector. Saves money and weight.
Good video. Thanks for your efforts.
A friendly comment. The coax is shielded and the length doesn't matter. Only the unshielded wire has to be the right length.
I hope you don't mind me mentioning this.
You did a nice neat job.
Best wishes.
That's not true, the length does matter as the feed line introduces inductive reactance and capacitive reactance that affect how well the antenna is tuned.
The tuning of the antenna is dependent on the length of the open elements, it has nothing to do do with the length of the feedline. A change in feed length changes only the impedance matching of the transmitter to the antenna..
That's only true if the cable were completely balanced. Coax cable is not a balanced cable and the length does affect the tuning. Coax cable will radiate a small amount of energy and does has an effect on the resonant frequency of the antenna system. An antenna is resonant when the inductive reactance and capacitive reactance cancel each other out. If I am designing two 1/4 wavelength monopole antennas with different length feedlines, the open elements will need to be trimmed to different lengths for the best performance and lowest SWR.
Nice build tutorial my friend I'm a bit concerned about matching the antena to the tx I would give this a go myself but don't want to blow my tx
At step on min 9, instead of hot glue you can use blue tack so its easier to remove.
great video, will print one tomorrow, im interested in why you are trying to tune the coax though? Isn't the whole idea that the coax doesn't allow the signal out so that it can be radiated from the antenna lobes? So a wave lenght would possibly be the worst thing you could do as you really want it to be not a wave lenght long as you don't want it to have a low SWR on the feed line?
nice! did you have results of video quality and range?
I have to make a transmitter antenna that is at least 150mm long. How long does the cable have to be at least that long?
My template kind of melted on the top layer and I had to trim back the top of all the inlays for the wire. Do you recommend a certain material and/or temp to print the template?
muito bom parabéns
Why would 6 lobes be better ? more sensitive than the standard 4 lobes ?
Why is the length of the coaxial cable important (51.7mm)?
+Gus Garcia (LOYO FPV) yeah I don't understand that either, the coax is a transmission line why is its length so important - it should be irrelevant (within reason)
+Gus Garcia (LOYO FPV) I have no idea why he bothers to measure the coax. He might be a little confused. Or He might not understand about the shielding. I like his little soldering jig. I really like it!
And, I think that the base he has made is fantastic. It has little slots to keep the spacing perfect. What a great idea.
I already have a jig for making the petals. Stick the wire into a hole, wind it around my jig...and cut off the wire. Done in seconds.
But, I like his soldering jig. It's much better than anything I've tried. I'll give that a go as well.
This is a very well made video....I think so. I would recommend that he edit out the instructions for measuring the coax. I hate to think of people wasting their time like that.
Best of luck to him.
If the coax isn't of quality it can sometimes reduce the effects of bad quality by making the length a multiple of a half wave length
If you do this, you need to account for the velocity factor of the coax cable. Then it will be beneficial. Otherwise it's just a lucky shot.
It is sometimes because of specific phase shift you need to have for the antenna to work properly
I made one from Thingiverse :) Now i have to test it
how about the result?
better than every antenna before .....great range
Results depend on who ever is building it and their skill level. For feedback, see: www.thingiverse.com/thing:938362/#comments
Awesome video and 3d templates, thank you!
your voice is ok, very well design and video but bed light source, we imagine what you do, anyway thank you for your effort :)