Increasing Gain with 15-degree Cone


#21

How does it perform? Ken


#22

I’ll get some numbers, with and without, when I get a chance. But my balloons appear to be staying green and I’m showing 100% valid packets, bitrate 20098, with SNR averaging about -11.5, although it’s naturally up an down a little.


#23

My numbers with my rough cup as above,100% valid packets, bitrate 20098, with SNR averaging about -11.5. I removed it a few minutes ago and the results with the bare LNB were: SNR -14, Bitrate 11762, Valid packets 95%. This was much better than when I first set things up a couple of months ago, and the first time I had tried the bare LNB since the recent improvements made in the signal. It appears my cup was only helping about 2.5 dB, but I guess that’s not bad for the ease of build and price.

I’ve gone back to my earlier oversize 5” X 2 1/4” X 9” square cone or horn which I posted about originally. It’s currently giving me: SNR -7, Bitrate 20140, Valid packets 100%. Now, just to find a way to make it portable!

IMG_1430


#24

Interesting - - when I made my first 8x4x2 " cone, I put the aluminum foil on the outside, then reversed it so the aluminum foil was on the inside and got better results. I’m wondering if you put the tape (aluminum duct tape I presume) on the inside if it would work better. Perhaps the Styrofoam is acting as a dielectric?

I really like your garden mesh horn antenna because of its durability and wind resistance. Ken


#25

Simple drawing of cone extension placed over LNB plastic case.

Cone_Extension_Plastic.pdf (587.4 KB)


#26

Drawing of cone extension placed over LNB with plastic case removed.

Cone_Extension_no_Plastic.pdf (261.9 KB)


#27

Syed, if we did something with these dimensions in a horn design, the horn could be removed for transport and folded up. If I mounted it on my Lantern case, it wouldn’t protrude too far either. Ken

PS - - I have a collapsible jumbo steel water mug coming which I will try. It is very close to your new measurements which I ordered after I saw your first post. Time will tell if the spec is right, and it performs as I like.


#28

I don’t think it could be folded up. This is a rolled cone. But it’s not super big.


#29

What is Outernet iteration 3 going to be? Is it a portable unit with a bare LNB or is it going to be a fixed some-what portable unit with a KONE (K-Band On-top Noise Eliminator) enhancer or dish?

Or will it have in the future, a new antenna that is flat and OMNI?

In the third world it has to be cheap, strong and simple.


#30

Here is my monday morning idea, With the recent signal reception improvements, and a reduced cone dimensional requirement, How about a package with multiple receive cones bundled into say a 12" box. Then allow the magic of electronics figure out which is pointed best to get a signal. Ultimately this would make pointing of a fixed station easier, and more tolerance for a moving ground station.


#31

I agree that would be simple. I think this was discussed a month ago. Possible 4 cones might be enough etc.

Remember cheap, strong and simple.


#32

Elizabethan collars for pets have splits and a tab alao you.could ad a beveled lip as a welding or glue point for metal…

alao whata the top, middle, and bottom hight of said cone… i have a few thia to try…


#33

The more I look at this the more I think this is a job for a 3D printer and some tin foil “duct tape”.

I am envisioning 2 types of cone; One square one made from 4x flat prints that would snap together to form the horn allowing for portable flat packed use. The other a cone that would have a small lip around the inside to allow for the correct placement and alignment of the cone against the LNB’s plastic cap. The outside would then be covered in in the same duct tape.

Print it in PETG for added weather and UV resistance.

If only I was any good at designing 3D things. I’m not that advanced with my printer yet. 3x rounds of brain surgery kinda got in the way over the last 18 months.


#34

I’ve read this thread with interest. I am tempted to endeavor in some experimentation (build a setup that allows changing out shapes/materials easily) but I sort of get the feeling from this thread that the whole topic of adding a horn or tube (be it providing shield or gain) has sort of become moot?

I have OK reception in good weather, but today it’s cloudy and rainy, and I’m hovering around -13 SNR.

The other day, in clear weather, I made a super-shaky square tube out of aluminum-foil and cello-tape, and was able to eyeball about a 2dB SNR improvement if I held it just right. Which suggests at least for me it’s the shielding that is helping… which makes me curious if even something absorbtive could be used, rather than metal/reflector… eg find a 3D printing filament that is lossy for RF, and then one could just print (or order a print) of a plastic piece rather than needing it to be metal. I’ve experimented with different plastics, thinking about putting the LNB into some sort of home-made radome… and that experiment told me it’s easy to find lossy plastics.

Anyway - is there any value in continued horn/tube LNB testing (for the general Othernet population - it would be of interest to me regardless)

PS: Since I have continuous SNR logging setup now, I can confirm that my SNR is worst each day basically when the Sun passes through the LNB/SES-2 azimuth

Will


#35

on a clear sky day, i was getting almost -12dB SNR with RSSI almost -80dBm (PER < 0.005) (variations were below this SNR/RSSI high-water mark) using the bare LNBF. but as yesterday was a variable rain day (heavy at times w/thunderstorms), the SNR fell to -14dB at best and the valid packets measure fell below 65% for as long as i cared to observe the LCD.
without adjusting the aiming after placing a 12.5mm wire mesh 10x20x5cm horn on the LNBF, valid packets returned to at least 98%. i observed nearly -9dB SNR and steady -78dB RSSI.
i conclude the answer to your question “is there any value?” is “Yes”.


#36

I understand that the various add-ons help. I was just wondering if there is any value to the community to come up with a test-bench and do direct A/B comparisons under controlled conditions to find out what’s best, or worst, or passable with perhaps smaller/relaxed design constraints. The data I’ve seen so far is someone tries method A under condition X, and someone else tries method B under condition Y.


#37

Many in this community have tried a great deal of experimentation in the past year. You are asking many questions that have already been answered. If you have not read all the forums for the past year, you have missed out on a lot, and I would encourage you to go back and read, for your gaining of much useful knowledge from the work or others at absolutely no cost!


#38

I’m partially to blame for not having put up a proper wiki yet.


#39

if you have the test facilities to do controlled tests, then please, by all means, do so! having solid baseline test results for bare LNBF versus LNBF plus wire mesh horn would very much be useful (esp. if we can compare in-the-field controlled test results with the predicted results the DC models produced).


#40

I meant a wiki for everyone to add their own information.