[Elecraft] OT -RFI question

[Jim Brown]

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