21

Ok- that works too. Thanks!

22

Looks like we got it! Thank you.

23

This is brilliant @k5ted !!!

The problem is that only the US uses “letter size” paper… the "international standard is “A4” A4 vs US Letter | Between Borders
Essentially, if anyone other than someone in the US ( or Canada) prints this out, it won’t work because the dimensions will be wrong…

I don’t have the time to fiddle with an A4 version ( I am off travelling tomorrow) , but i am sure someone can do an “international” version of the printouts :slight_smile:

24

Print it “actual size” and adjust the paper to the lines. There’s enough excess on the flange and left flap to compensate.

25

Oh, now this is positively BRILLIANT! If simple plans for stable, repeatable designs are solidified, then this could easily turn into village industries. The helix is generally more forgiving, but the optimized, patch with additional director(s) is more handy and low profile.

— Why Not Both ? —

How about combining these approaches and printing (or laser pre- cutting) the patch outlines on adhesive backed aluminum film (similar to a wide duct tape used in heating/cooling system ducting joints) and know dielectric foam as Syed suggested? This could be a village industry in the making, putting a little jingle in the pockets of small business entrepreneurs on the receiving end :slight_smile: The helix, as ki4its and other suggested, is also entirely printable and put together as a roll from the mailing tube - select a shipping tube that is already the correct diameter, and it’s already half built !

RadioRay …_ ._

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26

This design is only about 6.8cm tall. http://www.jpier.org/PIERL/pierl44/02.13093002.pdf

It could be made of simple materials.

27

And then there’s this: http://www.jpier.org/PIERL/pierl37/01.12110405.pdf

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28

How large does a no-LNA antenna need to be. We should be able to close the link with amplifier gain of 24dB, so that means (I think) that a no-LNA antenna would need to provide about 30dBi of gain?

29

Syed,
I wont answer for k5ted but wanted to let you know I have been playing around with different gain antennae without an LNA to determine exactly this here at the lab. I am up to an 11db antenna and get a stable 2db SNR. I am climbing the ladder to find the sweet spot

30

Is it a helical?

31

You’re almost there! All you need is 3dB to close the link. One point to make, though, is that without code lock, the SNR values on Skylark will not be accurate at all.

32

Yes sir it is Helical. problem with the gain we need for a no LNA antenna…the antenna starts to get a bit large and much harder to aim. I have been using librarian RPI version and viewing the tunerstatus SNR and RSSI readings.

I have much more equipment that I can use to measure all of this but I wanted to use your system from end to end to ensure it would work with it.

33

There is no practical patch antenna design that will approach the gain of a helical or dish antenna, without an integrated LNA.

34

A helical providing 28.8 dBi gain at 1539MHz by itself is about 16 meters long. (400 turns, .2 wavelength spacing) The beamwidth would be so narrow it would be nearly impossible to aim with any accuracy, without special equipment and mounting apparatus.

35

Would not the 30 db gain antenna have a very narrow beam width causing aiming issues?

36

Theoretically a multi-patch antenna patch antenna could work, with a combiner.

IMG_2957.JPG3024×4032 1.77 MB

37

Yes but it would be like 4 of the Outernet patch antennas together, spaced about 80mm apart. Very large array.

I still think the trick might be to stack amplifiers and use something like this:
http://www.jpier.org/PIERL/pierl44/02.13093002.pdf

If the goal is to create an inexpensive, small, standalone antenna capable of receiving Outernet with little to no aiming, then none of the above is going to fit the bill.

What is the goal? What is expensive?

38

As much as we want people to buy our kits and turn key receivers, we want people who can’t buy or products to make alternatives for themselves.

So the goal is for anyone with a DVB/RTL dongle to make an Outernet receiver with household materials. The LNA IC is dirt cheap, but the proven is not price. It is getting the LNA to the end user.

The holy grail is for anyone to turn a $5 TV single into an Outernet receiver, which just some glue, cardboard, and aluminum foil.

39

FlightAware has managed to come up with a dongle that has a filter and 19dB LNA built in, for $21. Can’t be that difficult to have it built with a 1539MHz filter instead. Then with a 9dB helical, we might be in business.

40

You’re right, it’s not that difficult. But selling you dongle online for $20 is very different from getting that very specific dongle into the far corners of the Earth. It’s not a matter of price or production, it’s a matter of logistics and distribution.

Somewhat unrelated: In the future, we’ll just have a $1 ASIC that dozens of manufactures are making Outernet products out of–or simply including into phones and tablets.

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