you got me interested !!!
I found this article on the web that includes a variety of design materials and some theory.
Think I will see what I can put together to test some of their ideas.
engr.colostate.edu/~notaros … tennas.pdf
you got me interested !!!
I couldn’t resist trying out the f5ann strip-line collinear as per the dimensions in @yooshky’s link http://f5ann.pagesperso-orange.fr/Anten%20…%20index.html
so I dusted off the toner transfer / PCB etching stuff last night and this is the result.
Unfortunately the PCB material I used appears to be slightly different to the FR4 that f5aan and @yooshky used, the antenna is only
getting around 50nm distance but admittedly that is unamplified and on around 12m of RG6 so is not a fair test.
A spectrum scan using directional coupler, noise source and dongle appears to show resonance? with a fairly poor impedance match
to 50ohms at around 1060 mHz, if my interpretation of these things is right.
So it looks like the strip-line sections need to be shortened, just not shore how much. Anyone have any suggestions or links to good
strip-line antenna calculators?
My Strip-line1090 (http://f5ann.pagesperso-orange.fr/AntenneStrip-line1090MHz/image/stripline.pdf)
The antenna has a limited visibility of obstacles. At the moment:
Other strip-line (worse, is too looooooong?) antenna:
Have you tried removing the small 20mm cable connector section at the feedpoint and soldering the coax direct to the antenna elements instead - is that difficult for you to do?
Ferric Chloride etching - yuk !
I made one of these last night (with a no etching technique) and initial test is encouraging - didn’t have time to do a prolonged test as it was late night and that will have to wait until the weekend…
f5ann.pagesperso-orange.fr/Anten … %20MHz.pdf
f5ann.pagesperso-orange.fr/Anten … index.html
I might have an innovative/novel method for making these stripline antennas that doesn’t need etching and anyone could make one.
I’ll reveal more once I have proven it a bit more (if it really works out!).
I have some bits on order and should be here next week sometime…
F5ANN uses commercial modeling software - Ansoft HFSS
I believe the “Positions Reported by Distance from Receiver” table is overstating the range you are actually getting. See here for details:
@yosshky, Did you use the same laminate material for both antennas? Or is there slight dimention diferences between antennas?
Anyway they are both giving much better coverage than I get here. Too many trees and hills :mrgreen:
@Devonian. Yes i did take off the 20mm matching section and attached a SMA directly to the bottom section, the match improved quite a bit a bit but resonance was still 20 or 30 mHz too low. I unsolder the sections and trimmed the ends a couple of times and of course… cut too much off so now its at a bit over 1110 mHz Anyway i have a different lot of 1.5mm DS laminate here so ill make another set when i get a chance, maybe it will be closer to the stuff f5ann and @yooshky are using.
The current build is not as good as it could be but is working roughly as well as a spider in the same (poor) location. The big thing with these strip-line antenna is that it obviously removes a lot of the variables you get trying to shove bits of coax inside each other for a COCO and expecting it to stay stable, at least it never worked for me…
I have a jar bottle of powdered Ferric chloride here that’s around 20 years old, maybe one day I might need to uses it (shudder) or maybe just chuck it out. Normally I use Copper chloride HCL+peroxide cocktail, (minimal mess).
The single dipole strip-line you linked is an interesting looking antenna and appears to perform well considering its size, was planning on giving it a try as well but didn’t have accurate dimensions so thanks for pdf link.
Looking forward to seeing to seeing how the no etch method go’s, the toner/ etch process is defiantly not for everyone.
Wonder if useing one of those conductive ink pens to color one in on a board would work… May have to pick one up just for fun. I could use my wife’s scrapbooking cutter to make an adhesive template, color the board in, then peel the template off leaving behind the trace…
Interesting… Somebody has done something like this for solderable circuits already with a craft printer :
And here is the most sophesticated 3D printed circuit - interconnection of brain cells (neurones)
These neurones continuously exchange electrical pulses between them, like the logic circuits in a cpu chip do, and this is how the brain functions.
Thats quite impressive, hadn’t realised those printers had come that far.
Next problem is to figure out the relative permittivity of the substrate material, that dictates the size of the elements, as i discovered the hard way. Here are some rough numbers but not sure how the element sizes would scale common materials
You may be overthinking this - check out my new thread…
Looks good. Where are you getting the blank FR4? Its easier to get the copper clad stuff here.
“Edit”- don’t worry, just noticed the link
Maybe, but I can cut that tape with wifey’s printer too…
hehe, now there’s a reason to do it (using wife’s printer).
The copper tape takes quite a bit of cutting, so be prepared for the wrath of the good lady after you bust her printer !
there is nothing wrong with a Jetvision A3 but…
you can try to make your own even better collinear antenna
look at my pictures at http://pa0ebc.nl/adsb/ADSB-collinear/
this is a homemade antenna and it is even outperforming my Jetvision A3
if you want to see results? look at http://pa0ebc.nl:8080
Hans Gort PA0EBC
Hey, on your above site you are using my drawing “Flavours of CoCo”
(1) Flightradr24 forum: 2014-05-29
(2) Planefinder Forum: May 31, 2014
Quick question if I may.
Does it make a difference which way up the coco is? Mine is simply suspended by the feeder and hangs ‘upside down’. As it isn’t rigid to turn it around I could tie a piece of string around the ‘top’ end and suspend it again.
I realised as I’m writing the answer will probably be, ‘try it and see’
Has anyone else concluded one way or another?
So long as it is vertical, there won’t be any difference.
If it makes you feel better, you could put the Pi upside down too!
Thanks, and also for answering my next question.