[Elecraft] An idea for the K2

[Bill Coleman]

On Mar 1, 2005, at 5:07 PM, WA2JJH at aol.com wrote:

> I use my K2 on CW and SSB. I was wondering how K2 Hams would feel about
> different grades of SSB adapters.

I've voiced this several times, but I'll reiterate.

I think the KSB2 is a great value at $89. It works, and gives 
reasonable performance. My K2 is probably unique in that I am using the 
"1.9" filter values as designed by KI6WX. (the bandwidth is closer to 
2.0 - slightly narrower than the original filter values, but (most 
importantly) with a lower passband ripple).

However, the KSB2 leaves a little bit to be desired.

1) it doesn't have a great VOX. The VOX works better with higher 
compression levels. If your mike has a low output, it may not trip. 
Although the K2 has enough overall gain (and there's another KI6WX mod 
to increase the tx gain), a bit of mike amplification would be an 
improvement.

2) the filter passband is kinda sloppy. It's actually amazingly good 
for its use of seven inexpensive crystals. Most radios use precision 
crystal filters that cost as much as the KSB2 or more. But, I'd be 
willing to pop for a more expensive unit that had a quality SSB filter 
with steep skirts and very little passband ripple.

3) single filter bandwidth. Even though the K2 has OP1-5, indicating 
that perhaps there are selections that can be made, there's only one 
filter. Two filter bandwidths would be nice - a wide and narrow, like 
most radios.

Of course, there is very limited space in the K2 for the KSB2 or 
filters. The KSB2 is already the hardest module to build, with the 
highest component density.


Bill Coleman, AA4LR, PP-ASEL        Mail: aa4lr at arrl.net
Quote: "Not within a thousand years will man ever fly!"
             -- Wilbur Wright, 1901