"Heard by few, touted by many"

[R.F. Burns]

I bet someone is driving really fast out there, trying to verify this for us.
Not on the NJ turnpike, I hope.
There's some roads in Montana that might be a good place to check this.
Somebody with a Learjet, tell us what speed HD radio works up to!
Do Learjets have windshield antennas, or 31" mast antennas for broadcast signals?

Maybe that's what the governor was trying when his car crashed. I can see the headlines. NJ governor hospitolized due to failed science experiment.

 

[radiopilot]

Doppler effect IS REAL. It's just that one must approach a large portion of the freakin' speed of sound for it to become significant. If you're goin' that fast in your car, you've got bigger problems than radio reception...like your liquified remains on the rear window

"Doppler Radars"

"You can hear the Doppler effect when a car or train is approaching you while sounding a horn. The horn pitch changes to a lower frequency once the car or train passes you."

http://www.wkrg.com/servlet/Satellite?pagename=WKRG%2FMGArticle%2FKRG_BasicArticle&c=MGArticle&cid=1031777069474&path=!weather!education

Wrong - you don't have to be going the speed of sound for the Doppler Effect !

Rarely have you two made such complete fools out of yourselves as this time.

A complete set of calculations has already been provided to you as to the effect of frequency shift on radio waves.

RP, as an aviation engineer, I would suspect you know better and are just playing around. Pocket OTOH.....

Radio travels at the speed of light. 186,000 Miles a second A car traveling at 60 MPH goes 1/60th of a mile in a second. That's a 1:11160000 ratio or a "Doppler shift" of 0.00000896 %.

At 99 MHz that's a change of .0008709 MHz. Most analog transmitters would be envious of this performance.

Perhaps a more graphical explanation is in order. One of the best ways to demonstrate how much Dopler effect there is on radio wave in a moving car is to use something that moves as fast as Radio waves as an example. How about your eyes?

Have you ever noticed that when you drive Towards a white object really fast it get's a reddish hue? And how if you look at it while driving away from it it's a little purple? Many times you need to try this several dozen times to really see it. Maybe you should get your keys...

Well there you go. That's "Doppler Shift". Right before your eyes.

Some people report being able to hear this on the radio as well. Remember how WABC records always seemed to be really fast? Doppler effect again.

Wonder why it doesn't do it anymore?

Must be global warming.

Pocket, you never cease to amaze me. and RP... You're kidding, right?

Clouseau

Good thing a fool like you doesn't design radio equipment or airplanes as the speed of radio waves = 300,000,000 meters/sec and NOT 186,000 miles a second.

I'm glad you graced us with your technical knowledge before you called US fools on a public forum!

Radiopilot

 

[clouseau]

Good thing a fool like you doesn't design radio equipment or airplanes as the speed of radio waves = 300,000,000 meters/sec and NOT 186,000 miles a second.

I'm glad you graced us with your technical knowledge before you called US fools on a public forum!

Radiopilot

You can call me out for inaccuracy, but you might want to tell everyone "HOW" inaccurate I was.

As you could have guessed, I used a commonly accepted speed of light number of 186,000 MilesPerSecond. If we convert the Metric number to miles we get 186411.3576712. My round off is accurate to 0.22%.

You wouldn't be trying to obscure the meaning of my original post by using shady tactics would you?

Clouseau

 

[Tom Wells]

Now class, just for extra credit, someone state the correct answer for speed of light expressed in units of furlongs per fortnight.