Dreamcatcher v3.02: Feedback Thread


#422

@tylerhoot I have one of those on order. look back a couple weeks on the forums for 26cm flat or model BWEI BT-682. Note it has a long shipping time… I ordered on 3/20/18 and it is on the ship ??? expected 39 days to reach the US. The outernet team had looked at them last fall. I will update when mine arrives.

Update 4/14/18: it arrived at ISC CHICAGO IL (USPS) facility on 4/11/2018… now it ?? somewhere in the USPS system ??


#423

@jason_matonis If you look back through this thread, you will find the picture of an old MotoSat antenna that I found here and did aim it with our Maverick Mk1 LNB in place. The small dish works well, but is impractical to the aims of our project. Fun to play with, for sure. The company here that took over the MotoSat company builds a unit such as you are looking at here. Be assured it is VERY expensive!


#424

@kenbarbi Thanks for the suggestion, Ken. I did have thoughts along that line, the cone was just easier at the moment and I had a few minutes to cut one out. I definitely want to test your design with the screen mesh. Would you be so kind as to quote again the measurements of one side, please? I think after making the cone, that this material is not as friendly as your light metal panels, for sure. However, just for the kicks, I will build one and see how it looks.

Also, I truly like what you have done with the Lantern. Good job!

@Konrad_Roeder, @Syed dittoes on the billionaire comment!


#425

@kenbarbi @Abhishek @zoltan @karascanlin This is so awesome, it almost made me cry.


#426

@zoltan
@Syed

Question: when we apply the horn type shield to the LNBF, does it need to be aligned to zero on the polarity/skew scale? It seems to me that this would be important, perhaps as much as “slewing” as Ken calls it, to the accurate pointing of our antenna device.


#427

Sam I am very interested in Mesh networking. I tried a experiment with one of the early Mesh experiments here in Philippines and it was basically short range and used a lot of battery. There was also some kind of problem with Android not allowing Mesh networks on certain versions of Android.

I would love to try again though.


#428

I think we have to give you a special prize Ken. Well done.


#429

@Seasalt I have been investigating the Mesh possibilities using the Lora capabilities of the chip used in the Dreamcatcher. It is usually called mode Lorawan. The current idea is to multipurpose or use multiple DC’s. I am running into to a few problems with the sx1280 transceiver drivers/setup with ambian on the DC. The lorawan is not opensource so I am be making this harder for myself, but it could allow me to ‘standardize’ my hardware on the future “Dreamcatcher’s”… with the bonus to the Outernet organization of generating more sales for hardware.

My goal is a long range mesh style network (albiet at low data rate) that uses low power devices.


#430

Jerry, the trapezoids are 2" x 4" x 8". I taped them together with aluminum tape. Perhaps with the garden mesh (after you cut off the poking wires on the long sides) you could bind them together with unlacquered 32 gauge transformer wire. The neat thing is the horn folds up easily for transport, and with the 2" dimension can be squeezed around the top of the LNB.

Here’s another photo of my setup in an obstructed environment (you can see the trees reflecting of the solar cell.

I’m getting signal lock with SNRs in the -11 to -13 dB range, and reliable downloads. Ken


#431

@kenbarbi How much improvement are you seeing with the horn? That is a really nice setup.


#432

Ken, I have the panels made, roughly. Thank you for the measurements and pictures. It was necessary to use aluminum tape on the long edges because of the uneven nature of the angled cuts. I will try to follow your lead with the attachment to the LNB, although this material is just stiff enough to make “forming” it difficult. I had thoughts of binding the edges as you suggested, but they would not stay aligned. Perhaps with a finer mesh this would work. It looks like I may need to use regular duct tape. So far the trapezoids weigh 2.2 oz, however, the final trimming isn’t done, nor are the corners bound yet. I may have to take a day or two away, but will keep you informed of how it goes…


#433

The 2x2x8 horn gives me a 3 to 4 dB SNR advantage with a clear view of SES-2 when I set it up away from my house in my antenna farm.

Next to my house (so I can be on my WiFi) it makes the difference between no signal lock and -19 dB SNRs, and signal lock with -11 to -13 dB SNRs. So I’m thinking the horn is actually shielding noise, rather than increasing gain, but I haven’t been able to prove that idea. I’ll have to work that with a complete house ac shut down with all my computers and UPSs off. Ken


#434

Ken,
In this video, Adam 9A4QV builds a cooking pot antenna. It’s essentially a turnstile in a pot. The pot is there for shielding from stray terrestrial noise.

To prove the sheilding theory, a Maverick in the pot ought to get you 3dB of gain as well. It should work on Ku band just as well.

–Konrad, WA4OSH


#435

Can you draw a simple network diagram of what you are proposing.


#436

@zoltan
@Syed
@Konrad_Roeder

Here is the “copy” of @kenbarbi Ken’s horn project, done in 1/4" hardware cloth (grid screen). I noticed a -7.75 once during aiming, however, was not able to acquire it again. It seems to center around 8.25 to 9. My opinion is that for the effort, Ken’s is better and easier. For the effort in building, the cone made of the grid material was much easier.


#437

Noise Shielding or Gain Improvement

After disrupting my wife’s meal preparation with a total ac shut down, I discovered my close in to house Dreamcatcher was not affected by signal noise from the house (as there was none). I was able to raise a -16 dB SNR (with no signal lock) to -12 dB with signal lock by adding my 2x2x8 horn for this test. My peak SNRs do change from time to time, but the gain improvements have remained constant.

This 4 dB gain improvement has been a consistent number where ever I run a comparison test, so maybe it’s not noise shielding, but really improved gain. Ken


#438

The antenna designers I’ve talked to concur with what you’ve concluded.


#439

For simplicity, I used 6" black stove pipe (round). Had a piece 16" long, duct taped the lnb centered onto the end and while it was sitting on my porch I got a signal. Note without the stove pipe I had a -16.5 dB snr and zero percent valid.

stove pipe 1

Update: after 15 minutes of it just stabilizing… -11.75 dB snr , 75% valid, 20178 bps data rate.

and green / green on status dashboard

I think a coffee or paint can could work just as well. Similar to the pringles idea, just more durable


#440

Just to close the loop, I made a 2x2x8 trapezoid horn out of aluminum screen material and was not able to improve the SNR no matter what I did. I don’t understand why that is since your galvanized 1/4" mesh works so well. Perhaps someone else might want to chime in here. Ken


#441

Do those antenna designers have any suggestions about the best dimensions for a horn operating at Ku frequencies? We could make a host of sizes and try them, but maybe an educated engineer could give us a break. I did find this table on line which seems to say we are in the right range with a 2x2x8 " horn - -