On Mon, 24 May 2010 13:05:03 -0400, Paul Christensen wrote: >Jim, that's probably the strongest coupling mechanism most of the time >although some receivers have poor shielding from the immediate environment >and noise coupling can occur from the SMPS to the receiver's front end.
>An example of this is the IC-7800 and IC-7700. There's a product review on >the web of the IC-7800 that boasts how the reviewer can hear many stations >without the need for an antenna! It's written as if that was a positive >attribute of the receiver. In fact, it only demonstrates how poorly the >front end is shielded between the preamp/mixer and the antenna ports. HAH! Very interesting. >Another disturbing attribute of the '7800 and '7700 is that harmonics from >its internal SMPS can be heard when the receiver is tuned from ~ 80 kHz >through 160m with decreasing amplitude as the receiver is tuned upwards. >Oddly, the noise increases as the antenna ports are deselected. Yet another great feature of a $10K radio. :) 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
