[Elecraft] OMNI VII vs Elecraft K3

[Bob Nielsen]

On May 14, 2007, at 1:53 PM, Bill W5WVO wrote:

> Anthony,
>
> I spent a long time lurking on the OMNI-VII Yahoo group and was  
> primed to buy one -- until the K3 was announced. In addition to  
> everything Greg says below, I think the most significant single  
> difference between the two receivers is that the OMNI-VII uses a  
> typical up-conversion scheme for the first IF, with its narrow  
> filters in the 2nd IF. The K3 uses a down-conversion scheme at the  
> first IF. This allows use of very narrow roofing filters in the  
> first IF, while the OMNI-VII must depend only upon optimizing IF  
> stage gain distribution to minimize close-in IMD through the first  
> IF. They obviously did a good job of that, as the 80 dB 2 kHz DR3  
> shows, but it is expected the K3 will test significantly higher  
> than that, most likely in the vicinity of the ORION-II. Of course  
> that's speculation at this point, since the actual numbers aren't  
> out yet, but it is well-informed, highly credible speculation.  :-)
>
> And you don't give away general-coverage receive capabilities, as  
> you do with many ham-optimized down-conversion receivers. It is  
> simply a brilliant design, IMO. I have one on order.
>
> Bill / W5WVO

That lead to a question I hadn't considered before.  How is general  
coverage in the vicinity of the first i.f. achieved?

Bob, N7XY