What is the purpose of the Black Boxes NCAA Officials wear during games?

[tjones1]

Read all about it here: http://www.precisiontime.com

If you ever get a chance to talk to Mike, do it! He's a great guy.

[Nevadaref]

Originally Posted by tjones1

Read all about it here: http://www.precisiontime.com

If you ever get a chance to talk to Mike, do it! He's a great guy.

"When an official blows the whistle, the belt pack recognizes the frequency of the FOX 40 whistle and sends a radio signal to the base station receiver that is connected to the scoreboard controller, stopping the clock at the speed of light."

Wouldn't that mean that the clock gets stopped at the speed of sound?

[JugglingReferee]

Originally Posted by Nevadaref

"When an official blows the whistle, the belt pack recognizes the frequency of the FOX 40 whistle and sends a radio signal to the base station receiver that is connected to the scoreboard controller, stopping the clock at the speed of light."

Wouldn't that mean that the clock gets stopped at the speed of sound?

No. But the clock is not stopped at the speed of light, either. The belt device can't do it's thing until it receives a signal, a signal which travels at the speed of sound from the whistle to the device. From there, a radio frequency signal stops the clock. That signal travels much faster than the speed of sound.

Edit: the radio frequency signal to stop the clock doesn't work at c, because by definition c is measured in a vacuum. Since we have the atmosphere to contend with, the speed at which the belt device stops the clock is < c.

[South GA BBall Ref]

I have actually used the PTS in the state tournament (private school) in GA and all is correct as indicated above with the exception of the frequency of the Fox 40. Actually it is the force of the air from the whistle that causes the transmission of a signal to stop the clock. A common procedure to make sure the transmitter is working prior to the start of the game is to blow a burst of air across the microphone to stop the clock.

[BktBallRef]

Originally Posted by South GA BBall Ref

I have actually used the PTS in the state tournament (private school) in GA and all is correct as indicated above with the exception of the frequency of the Fox 40. Actually it is the force of the air from the whistle that causes the transmission of a signal to stop the clock. A common procedure to make sure the transmitter is working prior to the start of the game is to blow a burst of air across the microphone to stop the clock.

Correct. We have close to a dozen schools that use it. Blowing air into the mic stops the clock. It has nothing to do with the frequency of the whistle. But I guess they think it sounds more technical.

[Scrapper1]

Originally Posted by South GA BBall Ref

Actually it is the force of the air from the whistle that causes the transmission of a signal to stop the clock.

Wasn't there a game in a conference tournament last year in which the clock stopped because an official was talking to a player?

[Brad]

Originally Posted by South GA BBall Ref

...all is correct as indicated above with the exception of the frequency of the Fox 40. Actually it is the force of the air from the whistle that causes the transmission of a signal to stop the clock.

Sorry, but that is not correct.

The system listens for three distinct tones from the Fox 40 whistle and stops the clock. I met Mike a long time ago at a camp in Tennessee where he was demonstrating the system. In fact, he mentioned to me that Fox 40 and him made some sort of agreement so that it would work with their whistles -- otherwise he was going to come out with his own whistle as well!

The system will not stop just because air is blown into it... If it did that it would be stopping all the time falsely!

[Nevadaref]

Originally Posted by JugglingReferee

No. But the clock is not stopped at the speed of light, either. The belt device can't do it's thing until it receives a signal, a signal which travels at the speed of sound from the whistle to the device. From there, a radio frequency signal stops the clock. That signal travels much faster than the speed of sound.

Edit: the radio frequency signal to stop the clock doesn't work at c, because by definition c is measured in a vacuum. Since we have the atmosphere to contend with, the speed at which the belt device stops the clock is < c.

I actually find this discussion interesting. The limiting factor in the whole process is whatever transmission is the slowest. We know that the whistle is making a sound wave in the air that is picked up by the microphone. There is then a relay of that detection to the belt box. That relay could be by fiberoptic or simple electronic. I don't know. Finally, the seller states that the box sends a radio wave signal to the control console. That is clearly done at below the speed of light. So I am saying that his claim that the clock is stopped at the speed of light is clearly false.
PS Lastly, the control console must receive the radio signal and then transmit something to the device that stops the clock.

Perhaps one of our esteemed members knows something about radio waves and how they are generated and can tell us at what speed they travel. I think that they are sound waves and thus cannot travel faster than the speed of sound.

[eyezen]

Originally Posted by Nevadaref

Perhaps one of our esteemed members knows something about radio waves and how they are generated and can tell us at what speed they travel. I think that they are sound waves and thus cannot travel faster than the speed of sound.

Put simply radio waves and light waves are both forms electromagnetic radiation that differ only in frequency. They both travel at "the speed of light" which Juggles correctly stated is less than "c" in an atmosphere.

Now frequency becomes important when the waves travels through a medium (again in simple terms a radio wave will slow down going through a wall but a light wave is completely stopped) but in this scenario is unimportant.

Sound waves are a different animal, they are compressions of the air around us and when those differences hit our eardrums we "hear" those differences. Hence why sound doesn't propagate in space.

[Nevadaref]

Originally Posted by eyezen

Put simply radio waves and light waves are both forms electromagnetic radiation that differ only in frequency. They both travel at "the speed of light" which Juggles correctly stated is less than "c" in an atmosphere.

Now frequency becomes important when the waves travels through a medium (again in simple terms a radio wave will slow down going through a wall but a light wave is completely stopped) but in this scenario is unimportant.

Sound waves are a different animal, they are compressions of the air around us and when those differences hit our eardrums we "hear" those differences. Hence why sound doesn't propagate in space.

Thanks. That is the kind of physics knowledge that I am seeking. I was wondering if radio waves were electro-magnetic. That makes much more sense than them being a physical product of the atmosphere such as the noise made by a passing car.

Now what is the speed of radio waves in a vacuum? Is it c or something less? Do electro-magnetic waves travel at different speeds or all at the same speed regardless of frequency?

I guess that I need to do some research on light waves as well. I never grasped that they were simply electro-magnetic radiation. I always thought that light was a physical substance that existed and traveled in wave form. I never did understand exactly what constituted a wave particle. I know that I had an excellent college physics class (taught by the Dean of Yale's physics department), but I must not have fully comprehended what was being taught regarding this.

[Freddy]

Whereas I'd bet we'll all be magically stopping the clock with our whistles, even on the high school level, sooner rather than later, I can see a just as great a benefit being able to have the clock started by an official at precisely the proper time.
Seems there are just as many unfortunate instances of the timer not starting the clock properly as vice versa.
Do you think that will be coming down the pike someday? Will we have to add "little black boxes" to our Christmas list, right below "air needle" and "keeps-the-shirt-from-coming-out-of-your-pants rubber belt with knobbies all over"?

[BillyMac]

Originally Posted by eyezen

Hence why sound doesn't propagate in space.

You must be wrong. I can hear those spaceships blowup in every one of those Star Wars, and Star Trek, movies.

[mbyron]

Don't get too excited about the gap between the speed of light in the atmosphere and the speed of light in vacuum (which has 3 syllables, BTW). The former is 99.97% of the latter, which is certainly close enough for government work.

The speed of an electronic signal through wire is also at least 96% of c, which again is close enough, where c is about 671 million mph.

The slowest signal in the PTS system is the transmission of sound from the whistle to the microphone, which moves at a measley 760 mph (though the speed of sound varies somewhat depending on altitude, barimetric pressure, etc.).

For comparison, the speed of nerve impulses in a human timekeeper is no more than 100-200 mph, or about 3 million times slower than c.

[LDUB]

Originally Posted by Nevadaref

Perhaps one of our esteemed members knows something about radio waves and how they are generated and can tell us at what speed they travel. I think that they are sound waves and thus cannot travel faster than the speed of sound.

Radio waves are light.