On 5/26/2011 1:01 PM, Ed, W9EJB wrote: > It was the digital modulation modes that caused some > problems; all of which have been fixed for many years now.
Note that what you're calling digital modulation is 100% amplitude modulation of a carrier by a series of pulses. For TDMA (time division multiplexing) the duty cycle can be as low as a few percent, so a 50mW cell phone can transmit 1W pulses. Most modern cell phones adjust their TX power as directed by the base station on the basis of their signal strength. Thus, a cell phone close to a cell site may run only 10mW pulses, while one in the far boonies may put out the full 1W (or whatever it's rated/licensed for). It's VERY important to understand this when testing for RFI issues. :) Many (most?) phones can be forced into full power mode for testing. 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
