[Elecraft] K3: is it SDR?

[Steve Kallal]

Sorry, but I'm not sure I agree. By that definition many radios since 
the 80s would be SDRs.

My definition of an SDR is a radio that could be radically changed in 
functionality by a software change. Perhaps the K3 fits that definition 
with firmware changes. But does the K3 modulate or demodulate a signal 
using analog or digital techniques. I am ignorant about the K3's 
architecture.

For example, early SSB rigs used a balanced modulator that nulled the 
carrier. Then a filter selected LSB or USB. I think true SDR would do 
that entirely in software. How does the K3 generate SSB?

OK, I am biased. I am a FLEX-5000A owner. That said, I'd love to have a 
K3, but it is beyond me financially right now. I love my K2/100 because 
it is NOT tied to a PC for basic operation. I plan to keep both radios. 
I'd also accept a K3/100 as charitable contribution, hi hi!

73,

Steve N6VL
K2/100 #2289

Lyle Johnson wrote:
>> So if one owns a K3, does that match your concept (or the ARRL's) of
>> an SDR?  How would YOU answer?
>
> It is IMHO.
>
> SDR means software defined, and the K3 is defined by software.  
> Whatever gets through the roofing filter is handled by DSP in transmit 
> and receive.
>
> This is quite different from PC-based, or open source, which is what 
> some folks seem to mean when by SDR.
>
> Frankly, most HF radios introduced in the 21st century are SDR, and 
> many in the 90's.  If it is IF (not AF) DSP, it is probably SDR.
>
> How does the ARRL define SDR?
>
> 73,
>
> Lyle KK7P