3 technical questions
Posted by
k6dgw on
May 29, 2019; 11:01pm
URL: http://elecraft.85.s1.nabble.com/3-technical-questions-tp7652460.html
I understand what direct sampling is and how it works. Why is it
preferable [or whatever other positive term you might want to use] to
the superhet design of the K3(s)? I'm curious what sampling the entire
spectrum from 0.1 MHz to 54 MHz buys me?
If I understand the "Superhet" option for the K4 correctly
[problematical at best], it provides RF and mixer stages to an IF [~8
MHz??] which is then directly sampled by the base K4. Since that IF
bandwidth can be adjusted by xtal filters and will be MUCH narrower than
0.1 - 54 MHz it will also be far less susceptible to overload from
strong signals not in that passband. Is this what's going on?
For reasons I cannot remember now, I thought the K3(s) oversampled the
15 KHz 2nd IF with a delta-sigma 1-bit ADC and decimated to the
equivalent of a 22-bit word. Some of the thredlets here have now caused
me to reconsider that belief. Have I got it wrong?
73,
Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County
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