DIY Antenna Reflectors and Horns

biketool · 2019-10-24T13:55:42.396Z

How did you make the case, looks to be a very naval grade rig.

kenbarbi · 2019-10-24T15:30:50.667Z

Turns out the case was one of Othernet’s original cases shipped to early supporters who bought into the Crowd Funding a couple of years ago. What Syed did was offer the then “Lantern” device to those who wanted it, or told them to wait for the production model which they are still working on

Back then, the “Lantern” was thought to be a L-Band device with a patch antenna run by solar cells. Well that didn’t happen - - but I kept the case and modified it to hold the Dreamctcher board and the LNB which I fixed into the case thru a rubber gasket so I could change the skew. After I concluded a cone improved SNR on the Ku-band LNB (some of us used martini shakers), I though to get a collapsible drinking cup so the cone wouldn’t be so hard to pack. It worked out well. My little traveling Gnome has had a hard life falling of balconies in Europe and getting soaked in the rain.

The case fits nicely into my luggage when I travel, and the electronics don’t move around getting disconnected. Ken

biketool · 2019-10-26T16:21:53.965Z

It is very cool, I am trying to come up with an idealized portable othernet rig for some remote work I will be involved with in not too long a time; but like too many DIYish gadgets in my life it will probably end up a bare circuit board wrapped in chloroplast and kapton or something.

wbrown · 2019-11-01T17:18:29.534Z

FWIW, I collected the results from the various designs I could find in the forums and it is here: Othernet_Reception_Enhancement_v02.pdf - Google Drive

The file is also linked in the Wiki in the horn section.

Will

Syed · 2019-11-01T18:55:49.140Z

I think this is my favorite post.

biketool · 2019-11-02T15:38:52.467Z

This is great!! Extra good for having dB improvement numbers; ideally we would have the dB numbers of a pool of users for each and average the improvement score for a given horn or dish design. Exactly this is the kind of stuff that needs to be in the back of the user manual.

spacebar · 2019-11-03T01:37:22.796Z

Hi Syed,

Can I get a refund on my Lantern backing?

Left a comment on indiegogo, contacted you on indiegogo, emailed the othernet website…no reply yet…

If you check any one of them you should be able to tell which backer i am and how much to refund me.

biketool · 2019-11-07T17:54:01.921Z

I just found something interesting

The Beach Behemoth Giant 12Ft Inflatable Ball

Brand:VEVOR
Material: 0.2mm PVC
Net Weight: 3kg/6.6lb
Gigantic:Measuring 12 feet from pole to pole
Diameter: 8Ft/240cm
US$80 free delivery on an auction site
Cut open and coat the natural inner 2m dish with a high aluminum paint and then with a dark color. It might be necessary to tape and inflate fully for the next step of using PVC tube cemented to patches with glue(acetone/dissolved PVC scrap) to suspend and keep the LNB aimed. Alternatively patch in a flexible reflective layer at the equator and use differential pressure to curve it into a 2.5m dish with easier external LNB placement like the GATR dish-ball(watch the video attached). This might be patented(almost certainly is) so it will remain one of those DIY only solutions. The user can also paint the outside if they wish to reduce the loudness of the ‘ball’ in their yard. I would love to see some of our northern users in Canada and Alaska outside the official footprint try this out!

m108-1.2.jpg1000×1000

VS $$$
satball

It makes me wish there was an amateur geostat to use this with, you need all the antenna gain you can get when fighting the inverse-square law, operating on a QRP TX budget, and minimum range is 35,786km.

Syed · 2019-11-08T06:42:11.907Z

I believe you were refunded a few days ago.

Syed · 2019-11-09T16:45:04.098Z

This has proven to be pretty reliable and does not require a tie-down under most weather conditions.

E6F7601D-9C25-4EA7-AFD5-9503D2017CB5.jpeg1536×2048 821 KB

Zebra · 2019-11-18T15:52:41.470Z

With my recent setup (LNB as supplied by Othernet), here in Germany, I do receive the Astra signal with a reasonable strength and SNR and 100 % vaild packets. I do know that there is no need to further imporve the SNR, but I like to experiment and have tried a mini-dish (40 cm), hoping to improve the signal. To my surprise the reverse is the case. With the LNB-only my SNR is -8,75 dB, with the mini-dish I get no signal at all, although the dish is directed (more or less) properly towards ASTRA.
Where is my mistake?

OthernetTestDish.jpg480×640 67.7 KB

biketool · 2019-11-18T16:49:40.972Z

Interesting, remember to calculate the offset when aiming the dish as what appears to be a straight on aim is actually something like 23° miss above the location of the satallite.
It looks like you have already calculated for the offset but for those reading the thread who forgot to include offset into the aim.

en.wikipedia.org

Offset dish antenna

Pages for logged out editors learn more An offset dish antenna or off-axis dish antenna is a type of parabolic antenna. It is so called because the antenna feed is offset to the side of the reflector, in contrast to the common "front-feed" parabolic antenna where the feed antenna is suspended in front of the dish, on its axis. As in a front-fed parabolic dish, the feed is located at the focal point of the reflector, but the reflector is an asymmetric segment of a paraboloid, so the fo...

and

rfcafe.com

Understanding-Standard-Off-Set-vs-Inverted-DishesBrian-Donalson.pdf

80.16 KB

demandzm · 2019-11-18T19:42:54.603Z

Without using your exact location. This may be wrong, but using a location of Germany tells me you need an elevation of 30.8 degrees. It looks like you are too high. Your pointing the focal point of your dish not the lnb/arm.Try pointing the dish closer to the horizon. Dont trust the elevation markings on your dish either. The 2 dishes that I have are over 20 degrees off.

Syed · 2019-11-19T02:37:50.276Z

I have several of those small dishes (they are really handy). When I point, I just do slow elevation sweeps while watching the packet LED.

ac8dg · 2019-11-19T10:45:41.256Z

demandzm:

trust the elevation markings on your dish

most of the small dish reflectors are “offset” as @biketool noted. This makes finding the focal point (or the distance to put the receive antenna) very difficult.

I like the othernet solution… Not using any reflector… lot’s of people said it could not be done.

wsombeck · 2019-11-19T11:43:14.653Z

Hi Zebra, I tried it the other way round: I first connected a standard sat-receiver until I received on 23E Astra TV Programs (Lyngsat-List) for azimuth alignment I used the direction delivered from Dishpointer.com. After good reception I connected the LNB to the Othernet-Equipment. SNR was about +8 dB as I remember. But now I am receiving with the bare LNB and get -7 to 8 dB with no packet loss.

Wolfgang

Robert · 2019-11-21T17:14:45.804Z

DSC02431.JPG3096×4976 2.44 MB

Hi,

I built an antenna mount from an old monitor stand, a hard disk mount of an old PC, a pipe clamp, an M8 screw and M8 nuts, double-sided tape and cable ties. I didn’t align the antenna very precisely either, as it is only provisionally positioned here. In the spring, I’ll set everything up at my weekend cottage. There I have no internet connection. Despite many WLANs the reception is good. SNR is about -9dB.

Robert from Berlin (Germany)

Syntax2600 · 2020-05-05T15:52:10.214Z

Syed, would you be so kind as to direct me to where I might find a tripod like this? Thank you!

Syed · 2020-05-05T16:24:57.081Z

Ha! That’s a purely DIY product. Maybe @Robert can provide details on where the parts were salvaged from.

biketool · 2020-05-06T07:55:17.632Z

I think the tripod is a cheap Asian mail order camera thing, I forget where the U-clamp came from, 3D print?