I'd also think twice before using a shortwave receiver on a comercial air craft (: I'd be worried about the emissions from the various local oscilators interferring with the HF and VHF radios on board the air craft.
Many years ago I used to use a portable sony shortwave receiver as a simple signal generator for making go / no go checks on UHF receivers. It's local oscilators put out easily detecable harmonics thru 470 Mhz. Regards Mark VE7AFZ ----- Original Message ---- From: "Lux, Jim (337C)" <[email protected]> To: Discussion of precise time and frequency measurement <[email protected]> Sent: Sun, October 4, 2009 2:21:22 PM Subject: Re: [time-nuts] GPS from a window seat > > But that doesn't change the fact that if a drunk businessman or a > bored 6 year old with a new toy can stealthily endanger all the > passengers on a plane, the responsibility - and liability - should be > with the aircraft designer. > > Bringing it back to the normal topic at hand, I wonder - if you had a > radio receiver tuned to WWV, and a GPS with a 1pps, if you could see > the relativistic effect of flying at 500 knots at 30K feet and log it > on your computer? 500 kts = about 250 m/s. C^2 = 9E16 m^2/s^2 V^2/C^2 = 6.2E4/9E16 = .6E-12 A pretty small thing to look for Uncertainty in frequency from WWV due to ionospheric issues is on the order of 0.1 to 1 Hz. Call it about 0.1 ppm for the 10 MHz signal. Doppler effect on frequency from WWV is 2.5E2/3E8 = 1E-5 (10 ppm), which is orders of magnitude larger than anything else you're going to see. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. __________________________________________________________________ Yahoo! Canada Toolbar: Search from anywhere on the web, and bookmark your favourite sites. Download it now http://ca.toolbar.yahoo.com. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
