Baofeng UV-5R What it really means

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Hanging out at the studio, again #3

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Internet Speed for Live Streaming on Major Platforms

Bitrate, frame rate and resolution are the three things you have to set when live streaming online. All of these factors will affect the quality of your video, how much processing power it takes to encode your video, and how much bandwidth it takes to broadcast your video. As a rule of thumb: it’s better to broadcast a steady video stream with a slightly lower resolution or frame rate than a super high-quality stream that is constantly buffering due to insufficient bandwidth or other network issues.

Here are the recommended Internet upload speeds for live streaming on major platforms. These include that 40% bandwidth buffer on top of the recommended bitrate (see above section):

Resolution
Frame rate        Twitch              YouTube           FacebookLive
HD 720p-30fps     3.2 – 5 Mbps        2 – 5Mbps         3 – 4 Mbps
HD 720p-60fps     4.4 – 6.2 Mbps      2.9 – 7.4Mbps     3 – 4 Mbps
FHD 1080p-30fps   4.4 – 6.2 Mbps      3.8 – 7.4 Mbps    6 – 7 Mbps
FHD 1080p-60fps   5.6 – 7.4 Mbps      5.6 – 11 Mbps     6 – 7 Mbps
QHD 1440p-30fps                       7.4 –15.8 Mbps
QHD 1440p-60fps                       11 – 21.8 Mbps
4k 2160p-30fps                        15.8 – 41 Mbps
4k 2160p-60fps                        24.2 – 61.5 Mbps

Giving Thanks 2023 style

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Hanging out at the studio, again

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Hanging out at the studio

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NETFLIX spam alert #5

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 I just find this very interesting.

A transit of Venus across the Sun occurs when the planet Venus passes directly between the Sun and Earth, appearing as a small, dark dot moving across the solar disk. This phenomenon is relatively rare and happens in pairs separated by eight years, with each pair occurring more than a century apart.

The transit of Venus is a celestial event that has been of great historical significance. The two transits that occur within a pair are approximately eight years apart, and the pairs themselves are separated by over a century. The last transit of Venus occurred on June 5-6, 2012, and the previous pair before that took place in 1874 and 1882.

Here's a simplified explanation of the phenomenon:

1. Orbital Dynamics:

   • Venus orbits the Sun at an average distance closer than Earth. However, Venus's orbit is tilted relative to Earth's orbit, so most of the time, Venus appears either above or below the Sun in our sky.

2. Transit Events:

   • Transits of Venus occur when Venus, Earth, and the Sun are aligned in a specific way. During these events, Venus passes between the Earth and the Sun.

3. Appearance and Duration:

   • During a transit, Venus appears as a small, dark disk moving across the face of the Sun. The size of Venus and the precise duration of the transit depend on the distance between Earth and Venus during the event.

4. Observation:

   • Transits of Venus are visible from Earth with proper eye protection or through solar viewing devices. Observers on Earth can see Venus as a tiny silhouette moving across the Sun's disk.

5. Historical Significance:

   • The transits of Venus have historical importance because they provided astronomers with an opportunity to measure the Earth-Sun distance, known as the astronomical unit (AU). By carefully timing the duration of the transit from different locations on Earth, scientists could use parallax to calculate the distance to Venus and, subsequently, the Earth-Sun distance.

The next pair of transits of Venus is not expected until December 10-11, 2117, and December 8, 2125. These events are rare and are often used by astronomers to refine their understanding of the solar system and the distances between planets.

ISS Transit Simulation

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The International Space Station

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PSA Credit Card Scam Alert #5

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The BEST Bulletproof vest and more

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I hear the repeater, but not my other radio

Is there something wrong?

In a duplex radio communication system, where you have two walkie-talkies trying to communicate with each other through a repeater, it is possible for both walkie-talkies to receive signals from the repeater but not hear each other when they are in close proximity. This situation can occur due to the way duplex communication systems are designed and the concept of the "duplex offset."

Here's an explanation of why this happens:

1. Duplex Communication and Frequency Offset:

   In a duplex communication system, one radio (walkie-talkie) transmits on one frequency while the other radio receives on a different frequency. This is necessary to avoid interference because a single radio can't transmit and receive on the same frequency simultaneously.

2. Duplex Offset:

   To prevent interference and allow for simultaneous communication, there is typically a frequency offset between the transmit and receive frequencies. This offset ensures that the two radios don't interfere with each other while communicating through a repeater.

3. Communication through the Repeater:

   When you transmit from one walkie-talkie to the repeater, the repeater receives your transmission on one frequency and then retransmits it on another frequency. The second walkie-talkie receives the repeater's transmission on this different frequency.

4. Close Proximity Issue:

   When both walkie-talkies are very close to each other, their own transmissions can interfere with each other due to "near-far" interference. The transmitted signal from one walkie-talkie can be strong enough to saturate the other walkie-talkie's receiver, making it unable to hear the distant transmission from the repeater.

To address this issue and allow for simultaneous communication between the walkie-talkies in close proximity, some advanced systems use technologies like Time-Division Duplex (TDD) or digital signal processing to manage transmissions more effectively. These systems allow the walkie-talkies to switch quickly between transmit and receive modes, reducing the chances of self-interference.

However, in traditional analog duplex systems, when both walkie-talkies are very close together, they may have difficulty hearing each other due to the near-far interference problem. In such cases, it's often better to communicate directly on a simplex frequency without using the repeater when you are in close proximity.

Latest NOAA Images

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