Tv Broadcast signal`s

[rabbit73]

Via my mobiel i can acces this Site , if i want to do this with my pc i get the massage; forbidden !?

mvg

I had a similar problem. There were so many ads my Norton security software wouldn't even let me logon. Using a Private Window helped, but the best solution was to join as a Pub Member / Supporter.

 

[primestar31]

The site is having issues right now, and Scott hasn't yet been able to nail down exactly what's causing them.

 

[rabbit73]

The SDRPlay series of SDRs has a unique feature not usually found in other SDRs. In addition to the usual relative dBm scale, it also has a calibrated dBm scale that can be used for absolute signal measurement when properly setup.

View: https://www.youtube.com/watch?v=MRR-x_TjOp4


johan:
Closed captions can be auto-translated to Dutch as shown in previous posts.

Here are some measurements of a Channel 2 ATSC 1.0 signal from a Thor modulator. They display as 31 dB SNR on the SONY TV, 89% Signal Quality on the Mediasonic HW250STB, and 4.4 dBmV on my Sadelco DisplayMax 800 Signal Level Meter.

2025-2-6 RSP1B SNR 31dB Measurements:

This was a closed system; no antenna
RSP1B center channel calibrated measurement: -60.1 dBm
Modulator > Variable attenuator > amp 17 dB > 4-way splitter for:
1. RSP1B
2. SONY TV: 31 dB SNR
3. Mediasonic 250STB: 89 percent Signal Quality
4. Signal Level Meter: 4.4 dBmV

For comparison:
Using the RSP1B calibrated measurement:
-60.1 dBm + 15dB BWCF = -45.1 dBm
-45.1 dBm + 49 = 3.9 dBmV; very close!

BWCF is Bandwidth Correction Factor

Next will be CH2 signals with local EMI noise added.

 

[rabbit73]

SETUP TO CREATE CH2 ATSC 1.0 SIGNAL
UHF/VHF Antenna
              \
          Combiner> Amp 17dB> 4way split
              /
ThorMod> VariableAttenuator
   /
HW150 to add UHF sig to Thor HDMI input
Splitter feeds:
1. RSP1B
2. HW250STB
3. SONY TV for SNR
4. HW150 to later add UHF sig to Thor
Attenuator was adjusted to produce 15 dB signal.

The above setup was created to add local EMI noise to the simulated CH2 signal from the Thor Modulator. The noise was from a VHF-High folded dipole. If I had used a CH2 folded dipole, the noise level would have been higher.

 

[johan]

Rabbit73

Do you have a photo or drawing of what is between your antennas and the receiver, in terms of splitter or amplifier. because I am overwhelmed with information. Everything well intentioned.

Mvg

 

[rabbit73]

Rabbit73

Do you have a photo or drawing of what is between your antennas and the receiver, in terms of splitter or amplifier. because I am overwhelmed with information. Everything well intentioned.

Mvg

I apologize if my previous post was confusing and overwhelmed you with too much information.

My setup was more complicated than what your setup will be for reception. My setup had to add a modulator to create a Channel 2 signal because I don't have any VHF-Low 2-6 channels here. I had to add an attenuator to the channel 2 modulator signal to show you different signal waveforms with the RSP1B for different SNRs to help you find an ATSC 1.0 signal:

1. Very Strong signal, SNR 31 dB, good picture on TV
2. Good signal, SNR 15dB, just enough for picture
3. Weak signal, SNR 5 dB, NO picture on TV
4. Very Weak signal, SNR 1 dB, NO picture on TV
5. Extremely Weak signal, SNR about -5dB because the signal is buried in the noise with only the Pilot Carrier showing above the noise at 310 kHz above the low end of the channel. In the case of CH2 the pilot is at 54.310 MHz

Yes, there is such a thing as a negative SNR.

I will draw a diagram of the setup you will need with your RSP1B, but it will take some time to do it. I will post it when I have completed it.

 

[johan]

Hello Rabbit 73,

a question ; do you have images of the frequencies of channel ; 2 and 3 and 5 and 6 . Exists channel ; 4 do ?!. Why do I ask that, Then I know how to set up my RSp1B.
For the rest: thumbs up for the explanation