Receiving program from AMC21 Ku, 125W through double pane window

[lost_mesa]

I once read about someone who had a C band dish in their garage (HOA issues) and claimed that it worked. I was very skeptical, so tried holding various pieces of wood in front of the feed. I was surprised that I could get some signal through a very dry piece of 2x4. Nothing though on Ku band. I think it might sort of work on C band if you have a thin wooden roof and can keep it very dry.

 

[cyberham]

I have 10' ceilings. I've thought about setting up a 10' mesh BUD indoors. It sure would look nice, but alas the windows are too small to permit reception of any signals.

I wonder if the inside of one of these on a winter day would make for cozy TV ?

View attachment 93113

How about an Ice Fishing Hut on your koi pond in the backyard? Good for COZI viewing.

 

[Kraven]

How about an Ice Fishing Hut on your koi pond in the backyard? Good for COZI viewing.

 

[polgyver]

Trying to add waveguide between LNB and its scalar

Cold and snowing outside, but now it is possible to do some experiments with waveguide, in comfortable environment...
32" long pipe does not reduce signal Q, but another pipe with two ninety degree bends reduces the Q by 15 - 20 %.
Does anybody know, if it is possible to sum (add, or mix) the signal from 2 or 3 such scalars to one LNB?
Just thinking of utilizing 2 or 3 pizza dishes...

 

[Titanium]

If the bandwidth (the complete transponder frequencies) and polarities have no duplication, it is possible to merge the signals from multiple satellites into a single LNB. There will be major phase issues to deal with, but it would be a fun project just to say "I did it"! Maybe add a mechanical divertor to turn the signal "spigot" on and off! :

 

[FaT Air]

Don't think it's at all practical. First big hurdle would be getting 2 or 3 at the same phase angle where you'd 'add the together'. The wavelength at 12Ghz is short,(1/2 inch?) so a discrepancy of just a fraction of a mm would result in huge losses IMHO.
BUT: your wave guide could be run from an outside dish to an interior 'Lab' for LNB(F) testing without regard to the weather. Who needs that expensive WR75? Looks like 3/4 copper seems to be 'just the ticket'.

 

[. Raine]

Trying to add waveguide between LNB and its scalar

Cold and snowing outside, but now it is possible to do some experiments with waveguide, in comfortable environment...
32" long pipe does not reduce signal Q, but another pipe with two ninety degree bends reduces the Q by 15 - 20 %.
Does anybody know, if it is possible to sum (add, or mix) the signal from 2 or 3 such scalars to one LNB?
Just thinking of utilizing 2 or 3 pizza dishes...
View attachment 93469View attachment 93470View attachment 93471View attachment 93472View attachment 93473

I don't know if it would make a difference or not for satellite signals, but do you have any rectangular pipe, conduit or whatever that you could try for your waveguide instead of round pipe? I've seen and worked with microwaves in other applications and the waveguides are rectangular, not round. With the rectangular, you may be able to make a 90 degree without losing signal, possibly?

Don't know for sure, I've never done work with low power microwaves like satellite signals to the point of building waveguides, only high power, but it might be worth looking into. Different diameter pipe may change your loss too, Ku, 0.622 x 0.311'', C, 1.372 x 0.622'', somewhere close to around those sizes, I think.

Great pictures, setup and I love the idea of it. Looking at your rig, I wish I had the time to play around with similar myself! Maybe come summertime when I'm not so busy.

 

[FaT Air]

http://www.commscope.com/catalog/wireless/2147485683/product.aspx?id=69

 

[Cham]

Trying to add waveguide between LNB and its scalar

Cold and snowing outside, but now it is possible to do some experiments with waveguide, in comfortable environment...
32" long pipe does not reduce signal Q, but another pipe with two ninety degree bends reduces the Q by 15 - 20 %.
Does anybody know, if it is possible to sum (add, or mix) the signal from 2 or 3 such scalars to one LNB?
Just thinking of utilizing 2 or 3 pizza dishes...

Certainly possible.
Looking for something already done in my engineering books, I know I have run into this in the past.
NASA does it electronically using the Deep Space Array but that requires lots of processing power and would not likely be real-time for watching TV...

 

[Cham]

Found a document that might give you some ideas.
Will see if the .pdf attachment works...

Interesting concept especially for FTA, since most signals are on C-band, being able to combine inputs from several Ku dishes might circumvent some HOA issues. Lots of places you see 2-3 Ku dishes mounted on one home because they switched providers etc, and they never removed the old equipment. 2-3 1m dishes combined would be interesting.

The other option would be to combine Ku dishes to reflect to one feedpoint, affectively making it a prime focus assembly... maybe too big of a project for the living room.

 

[Balock]

I found this introduction to waveguides informative:

http://www.radio-electronics.com/info/antennas/waveguide/waveguide-basics-tutorial.php

 

[polgyver]

Gentlemen,
Thank you for valuable suggestions and links to waveguide info. I am going to try to "inject" the signal from 2 sources to one LNB, and will have to make more trials (tinkering) as there is no ready info about it. My 2 small dishes will be aimed at one satellite, as the goal is to increase useful area. Each dish - behind one wing of window, so the central bar would not obscure signal.
The micro HD and Geosat-Pro LNBF are really great - as they enabled me to scan the 123 W just from behind the double glass! What happened, I just carelessly reset MicroHD to factory "state", so I lost all previous scans. Avoiding to go outside (ough! Cold!), I tried three times to scan from the room, and on third attempt, finally got the 123 W. Cheers, polgyver