Tv Broadcast signal`s

[Jim5506]

But wouldn't that apply just to an earth orbit free of gravitational influence of the land mass? An air path should be no different from a land path as far as straight line heading

Gravity is not a factor here. A ground path is tied to the rotation of the earth's surface and an air path is mildly associated with the movements of the atmosphere. If observed from above the great circle path is a straight line at any one instant but the air path is not tied strictly to the ground path. From an outside observers vantage point the ground path is an arch because the turning earth is not allowing you to drive a straight line. It may be compared to landing an airplane in a cross wind, you point the plane on a vector slightly away from your destination because the wind alters your flight path to match the ground target.

 

[johan]

Have a question, is there also a program where you can calculate how high I should set my antenna ?!. live in the built-up area and to place a mast of 30 meters high there, I ask for trouble. Mvg

 

[rabbit73]

most videos with an Sdr go too fast and especially the mouse and the controls. Hope it works out Rabbit73

In post #63 I showed how the RTL-SDR V3 dongle could be used with SDR# to see the low end of an ATSC 1.0 channel.

This is the V3 dongle with an antenna adapter cable. I usually connect it to the USB port of my laptop with a short USB extension cable. The newer V3s have a black case.

I will now show how the V3 dongle and GitHub RTLSDR Scanner software can display much more bandwidth than one channel.

Check that V3 is in Device Manager:

This is the Scanner software:

Video
Download and view now
Dropbox

Download now, view later
https://www.dropbox.com/scl/fi/vo8b...ey=9o5fon9e79zyfpcvr0m2glj9l&st=84bg6h41&dl=1

Next, I will try to add an ATSC 1.0 channel with a modulator.

 

[rabbit73]

Have a question, is there also a program where you can calculate how high I should set my antenna ?!. live in the built-up area and to place a mast of 30 meters high there, I ask for trouble. Mvg

There are such programs, but antenna height is more important with LOS (direct Line-of-sight) signals.

Place your antenna as easily as possible to avoid trees and other buildings that might block the signals. Avoid power lines for safety and to reduce electrical noise interference.

 

[johan]

Have a question, is there also a program where you can calculate how high I should set my antenna ?!. live in the built-up area and to place a mast of 30 meters high there, I ask for trouble. Mvg

I found this program, but haven't figured out how it works yet.https://www.omnicalculator.com/physics/fresnel-zone. Could someone help me with this too.

 

[rabbit73]

I found this program, but haven't figured out how it works yet.https://www.omnicalculator.com/physics/fresnel-zone. Could someone help me with this too.

That program is not useful for your DX TV Project because your signals are not direct, they are by rare great circle propagation. I will not demonstrate that program.

 

[rabbit73]

I found this program, but haven't figured out how it works yet.

I suggest you look at some of Hepburn's links. He is a Propagation expert.

https://www.dxinfocentre.com/tropo_nat.html

Hepburn Tropo Index

Tropospheric DX Modes

DX Info Centre

Check with local radio amateur hams. When the 6m band is open, DX TV might be good.

 

[johan]

Oke,thank you fore that answerd

 

[rabbit73]

Here is Channel 2 added to the VHF-Low Scan.

If you have strong local FM signals, you might need to add an FM trap (filter).

Next is RSP1B examples.

 

[rabbit73]

Hello Rabbit 73, I have an RSP 1B as a recipient here. I assume that it also works. Or does it necessarily have to be an RTL - SDR V3 dongle. And you can show in a video how you work. Pretty interesting I think.

johan

This is how I have my RSP1B and SDRuno setup for ATSC 1.0 signal measurements. I only need to use these 3 windows for measurements with my laptop.