A balcony dish for (South facing) apartment dwellers

[polgyver]

Got a lot of encouragement from my recent post responders. Perhaps this post is premature, but I would like to get unbiased opinion on this idea.
Hope RimaNTSS chimes in, as some of his appreciable collection of sat dishes are balcony installed.
Got this idea quite a while ago. Some of our friends asked for dish installation on a balcony, and the building administration was not opposed to it.
However, some condo rules might prohibit dish installation on the balcony rail.
But, if the dish is closer to the window, and not visible from outside (from the street), the tenant could get away with it.
The only problem is, that the LNBF with its bar would protrude towards the balcony rail, thus making it difficult for apartment dwellers to fully use their balcony, for example : bringing in their bicycle, or other items, or, even walking on the balcony floor.
The idea is : get rid of the LNBF bar. Make the paraboloid of such a focal length, that the LNBF could be fastened to the balcony rail (or, below it), so, nothing could be seen from the street.
Now, the dish "bowl" could be of standard, say, 90 cm diameter, but its focal length could be optional, say, 120, or, 150, or, even 180 cm - offered by the vendor.
The advantage is obvious : The bigger focal length, the better dish's "selectivity" (possibility to receive sats even 2 degree apart).
Imagine a few LNBF's "sitting" on the balcony rail (or, on a threaded rod from this rail), allowing for reception of many programs...
The only problem is, that we depend on dishes, manufactured in Taiwan or China, and they come with standard focal length. Why? Because all LNBF's are made with 85 - 90 degree angle of "sight".
For balcony special dish, the LNBF should have another angle of "sight", say, 30 or 50 degree. Maybe this could be obtained by added-on extra scalar.
Probably there are millions of apartment dwellers, in the USA alone, many of them in rooms facing South.
Could it be a business idea?
Cheers, polgyver

 

[Cham]

Wonder if one could fabricate a reflector using an english wheel or something similar... at least just to try out.
Another thing to try is using a flat piece of aluminum or other reflective surface to bounce the signal 90 degrees into a normal dish facing this reflector... Likely little space advantage in most cases though. Would work better if the balcony is at an angle to the south or preferred satellites' direction.
Agree a longer focal length will allow closer LNBF spacing for adjacent satellite reception. Most balconies are fairly narrow, and adding in the reflector and supporting structure you might be looking at less than a meter for focal length. With a 36"-40" reflector a regular LNBF would likely work. With the LNBF attached outside of the balcony perimeter there are more possibilities... as long as the supporting structure is not too obtrusive.
Your 11m focal length dish would be a bit much though (unless you can install it on the balcony across the street!

 

[Titanium]

I enjoy that you are thinking outside the box. I would suggest going the opposite direction. The flat antenna or phase array would be more invisible, be much more useable in a confined space and simple to install and maintain.

From the viewpoint of an installer and technician, folks have enough problems aiming a dish with the LNBF attached.

If the reflector was to be mounted away from the railing, it would need to be low to get the look angle below the balcony or roof above. The long distance throw on a high FL design between the reflector and the LNBFs would need to be kept clear, so no chairs, tables or walking. Balcony dimensions vary so much that many focal length models would be necessary to facilitate the distance between the reflector and the rail.

Be a fun project for a hobbyist!

 

[RimaNTSS]

polgyver - is that so bad weather in Toronto that instead of working on your dishes you do out-of-the-box-thinking? Just kidding.
I think one more way of installing of the dishes could be added to your ideas, and that is offset antenna upside-down installation. This could be suitable especially to balcony installations.
I think for balcony's we need short-focal length antennas.
And, lets call LNBF's angle of "sight" - "Illumination angle"

 

[Cham]

Phased array would be interesting.
For Ku the wavelength is about 1.5" I think, 1/2 wave at 3/4" driven element length (antenna) elements in a yagi configuration say 6 elements long. The driven elements should be at least 1/8" diameter to create a wider bandwidth. The 6 element yagi would be around 6" long, maybe a bit longer at these wavelengths.
Now a phasing harness using trace leads on a printed circuit board designed for high impedance maybe 300 ohms, so standard 8.5X11" size board could handle 6 of these antennae elements using the PC phasing system.

Now attach these circuit boards together and match impedance, maybe 6 or so.

One 6 element yagi has maybe 4dBd gain. 6 phased together on each PC board would make about 11dBd expecting some losses in the on-board wiring (phasing traces) system.

Now adding 6 boards together would bring it up to around 18dBd thereabout with anticipated circuit losses? (This would be close to 20 dB gain compared to the theoretical isotropic antenna in free space). Imagine 6 standard paper sheets as the receiving antenna... likely situated in a close group, kind of resembles the size of a satellite dish.

The aperture would be at least 5 degrees thereabout in both polarities (this is a linear antenna, similar can be done with a circular as well). Not sure if 20dB will cut the mustard though. Would have to add more yagi panels... An antenna the size of a piece of 4X8 plywood should work, and possibly narrow the aperture to below 3 degrees? Now attach a new high gain LNB circuit to this antenna and there might be some magic!

Now this is just thinking out loud after a couple beers... Think I need another one!

 

[Titanium]

Sorry, wasn't referring to a phased array of yagi's (though that would be geeky looking and interesting). I was meaning a flat panel phased array or metamaterials surface technology. Other solutions which are currently less expensive and more traditional, CubSat or a horn design - Selfsat or Easyfind, etc.

 

[mr3p]

Since you referenced a collection of balcony satellite dishes, here's mine from a 5 years ago

http://www.satelliteguys.us/xen/attachments/post-8-jpg.56313/

 

[polgyver]

I enjoy that you are thinking outside the box. I would suggest going the opposite direction.

Got confused a little...
Seems, I am fairly well "inside the box", as I suggest keeping the concave dish and LNBF, our typical means of reception. The only "wall of the box" I tried to push, is - getting rid of the LNBF V-bar, thus enabling balcony users to walk there (assuming the dish is sitting on the brick wall under the windows). Temporary reception interruption would not be a problem when someone walks there, just momentary break...
I think your and Cham's ideas are more "thinking outside the box", since both of you suggest getting rid of typical concave dish and LNBF and installing a flat array (kudos for both of you for innovative thinking).
BTW, Ku wavelength is about one inch (appr. 25 mm), assuming speed of electromagnetic waves is 300.000 km/sec, and typical Ku frequency is 12 GHz.
Upside-down installation suggested by RimaNTSS would result in the dish, now almost horizontal, protruding towards balcony rail, making it more difficult to walk on the balcony.
Using English-wheel is also good idea, but, this method delivers prime-focus dishes : for a balcony install, offset dishes are more practical, as they are more vertical, thus, not being an obstacle for walking by.
Cheers, polgyver