[TenTec] Question regarding Omni VI+ on SSB

[Jim Brown]

On Thu, 25 Nov 2004 12:33:52 -0500, Charles Greene wrote:

>Agree with the ratings but you need to differentiate between the K2 and 
>K2 with DSP.  The K2 with DSP is one notch higher than the K2 without 
>it.  I'd give the K2 with DSP an 8 as a SSB rig.   

I disagree. DSP is a big plus in the K2, and I'm assuming it. I very much like the DSP in 
the K2, and it works very well both on CW and SSB. But it is an AUDIO DSP, not an IF 
DSP.  

The limitations on SSB in the K2 and K2/100 are 1) low gain in the audio and 
modulation signal chain, thus poor "oomph" on transmit; and 2) very limited IF filtering 
for SSB. In essence, the only GOOD receive filter for SSB is the transmit filter, which is 
excellent. To get narrower, the CW filters, which are rather narrow, must be stagger 
tuned for SSB reception. They work GREAT on CW, which is what they are designed 
for. They are AWFUL when stagger-tuned for SSB. Their response looks like a side 
view of the Rocky Mountains, and they sound as bad as they look. (And yes, I've 
carefully aligned them using spectrum analysis software, and I've measured several 
K2's aligned by very good engineers.)  

#1 can be fixed by some mods that were developed by several very sharp builders, and 
are published on the Elecraft website. #2 cannot -- it is a limitation of the design of the 
K2. 

I love my K2/100 DSP and KAT100 -- it is a world class CW rig, and my favorite CW 
rig, especially for contesting. But it is NOT a world class SSB rig -- at best, it is an OK 
SSB rig for casual use. 


Jim Brown  K9YC