Outernet patch antenna

Hi
Can the patch antenna be mounted in a plastic box for protection. Wasn’t certain if it will degrade performance. Would it be ok to use double sided foam tape on the front metal plate to secure it to the box. Any ideas welcome.

Thanks

That is indeed my plan. For temporary testing, I have it in a zip-lock bag outside and there doesn’t appear to be any drop in signal strength.

I would not imagine that a solid plastic would reduce the signal either, but I’ll certainly lay a piece in front of the antenna first to test it.

-Scott, K4KDR
Montpelier, VA USA

We’ve seen signal degradation with our enclosure, due to near field interference (or so we think). It’s a loss of about 3dB of SNR from a black ABS plastic enclosure that is .008-inches thick.

I would try not to put anything on the satellite-facing part of the ground plane. The reverse of the ground plane, however, is not a problem. We’ll eventually be placing the entire SDR directly under the ground plane.

IIRC, conventional wisdom is that if a container doesn’t heat up in a microwave oven, or is marked as microwave safe, then it’s probably OK to use as a radome, at least in this part of the spectrum.

UPDATE:
If it melts, it’s probably no good :slight_smile:

Cheers,

Darren, G0HWW

I had a quick duck duck go on the issue of Fibreglass attenuation of a radome.

Do you g0hww know where I could see a graph or list of diffenernt materials attenuation properties at 1.5Ghz.

It appears to me polyester fibreglass is a OK choice but I would alos be interested in other options.

I don’t know of any such info and googling didn’t come up with much, other than some mil spec docs that talked of fairly exotic materials (well, in terms of home-brew tech). There was this forum post:


that hinted at certain types of plastics, but nothing specifically for L-Band, though I doubt if the issue is particularly frequency specific in this part of the spectrum.

I like the suggestion of goretex. I’m now imagining my L-Band-kit-on-a-bamboo-stick wearing half a pair of surplus camouflaged trousers. Some kind of urban pattern would probably be ideal :slight_smile:

I agree interesting.

So goretex is basically invisible?

HMMM…Syed is saying a Lantern will still decode at a SNR of 2. I think.

I am able to get about 7-8 in tropics lying down flat the bare DIY antenna and open sky.

Under a blue plastic tarpaulin i get like 6-7 SNR

If I put a fiberglass radome dome i intend to use as a radome over the DIY Lantern antenna and still under the plastic tarpaulin i can get about 5.5 snr.

So it appears anecdotally a Fiberglass Radome 1mm thick has a SNR attenuation of 1.5 to 2.00.

Bringing my normal signal to from eight SNR to six.

Six is probably plenty in the tropics except on the most severe rain fade events.

On question is shape of radome. One of the forums talked about the radome material refracting the signal. Is this worth worrying about at 1.5ghz.

I guess it would depend on the shape of the radome and the geometry of the antenna and the LOS. For a Lantern style box, I wouldn’t think it would be an issue.

Not withstanding the power issues I’ve brought up on another post, Syed is right about the attenuation of the black antenna cover - about 2 -3 db reduction in signal strength.

I found a “sweet spot” on my deck rail where I can easily see I4-F3 here in Washington, MD, and have covered the whole apparatus with one of those clear plastic storage trays to keep the unit dry. I have the Lantern plugged into live power with a 2 amp wall wart, and don’t seem to be losing more than maybe .5 dB of signal. Hard to really say with allot of precision as the SNR bounces around a bit. Ken

The material of the black Lantern cover is ABS. It’s about 2mm thick, which is similar to the thickness of that container you are using in the picture. The problem we are seeing is that the cover is too close to the antenna. This can be resolved with retuning of the antenna, but since the enclosure has been in a state of flux, this has not yet been done.

Hi all,
I would like to point out that the regular Kit with the Patch Antenna, LNA and RTL v3 work very well… with CHIP and OS Skylark 4.4

Actually, today it is sunny and here is the SNR… inside behind a high efficiency window.

Here is my installation:

Behind:

Nothing fancy at all… just a regular tablet holder for car…
Maybe if I shield the LNA and put it outdoors it could be better… well that would be in the summer!

73 to all, Richard.
Montreal, Canada.
March 16, 2017.

works fine in this ABS box, sitting inside a South facing window

This box is on sale now for under $11 http://a.co/gCWAFLc
It is a perfect fit for the antenna and gear.

Right now I use it with lid open, using a short dowel to prop the lid and antenna up at the correct 35 degree angle.

Still working on a ventilation scheme to allow it to be closed tight and not burn up. SDRx might work better in this closed box, or any closed box, for that matter.

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SNR is of 12dB is just bananas!

Good reception tonight in S. Texas

This one?

Have you looked into seeing if heat buildup may actually be the cause? SDR could become less sensitive as it heats up. It would also make sense why @k5ted is getting good results with his heat sinked setup.

Nothing exotic needed, really. Just look at GPS antenna enclosures.

wow! you win the SNR wars hands down :slight_smile:

Hi Neil,
Just imagine outside… I’ll try that this summer.

It amazing that many of us, including me, want to build something better…

For now it does the job more than needed.

Have a good one!

73’s all, Richard.

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My Outernet patch appears to be doing good, on the windowsill looking through the window.

I can only drag maybe 7db on a good day outside on Alphasat from the UK!! 4-5 is most normal :slight_smile: