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.

 

[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.

Since you already have an RSP1B, there is also available the RSP Spectrum Analyzer software:
Analyser download and installation

I had the original version of the software working, but I haven't yet been able to get the new version of the software to work.

Maybe you can get it to work with your RSP1B?

 

[johan]

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.

View attachment 178282

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.

View attachment 178283

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:

View attachment 178284

This is the Scanner software:

View attachment 178285

View attachment 178288

View attachment 178289

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.

Where did you buy these cables. Mvg

 

[rabbit73]

Where did you buy these cables. Mvg

Hello, johan. I was wondering how you are doing.

I use that SMA to F adapter cable on all of my SDRs to take the strain off the SDR antenna connector.

RSP1B Datasheet Link

I buy them on eBay (US or China) or Amazon.

Do not buy RP-SMA; it does not have a pin.


Other type adapter cables

 

[rabbit73]

What kind of receiver do I need to receive the ATSC signals.

Mvg

I like the Mediasonic brand as suggested by FTA4PA in post #9, but the ATSC 1.0 model I like best is the HW-250STB because the remote control is more responsive to commands.
Mediasonic HW250STB

Mediasonic Store

Mediasonic HW250STB Manual Link

My next post will be a tuner sensitivity comparison between the 250STB and my SONY TV.

 

[rabbit73]

In Jan of 2021 I compared the sensitivity of two tuners, my SONY TV and a Mediasonic HW-150PVR. The method I used was to connect an antenna to a variable attenuator and then to a splitter for the 2 tuners. The details are here. (That site is down sometimes)

Antenna > Variable attenuator > splitter

I reduced the signal with the attenuator to find the dropout point of the tuners. The SONY tuner would dropout when the signal Quality was less than 15 dB; the HW150 would dropout when the signal Quality was 39%. The tuner that dropped out last was more sensitive to weak signals.

I showed the shrinking signal waveform with an Airspy R2 and Spectrum Analyzer software. Spoiler: they both dropped out at the same time, indicating equal sensitivity to weak signals.

In order to check the sensitivity of the HW250STB tuner for johan, I did a similar test with my SONY TV and the RSP1B to show signal waveform. However, instead of using an antenna signal, I used the signal from a Thor ATSC 1.0 modulator to avoid including the variable of antenna noise. (Later, I might do a test with an antenna to show how much stronger a signal must be to overcome my high local noise level).

Thor modulator > Variable attenuator > splitter

More after some sleep.