[Elecraft] K2 10m sensitivity

[Alastair Couper]

I have just received a new old K2 here. It has most of the important mods,  
AtoB upgrade, and is working as well as it can, as best I am able to  
determine. The alignment is fine, and it puts out OK on all bands. I have  
not been able to find any posts about the sensitivity on 15m-12m-10m being  
not so great. On 40m-80m-160m it is what I would expect. 20m it's just OK  
with wider filters, but there is plenty of internal noise with the  
narrower filters.

I don't have a microvolt source to get a precise reading. But with a 5 el  
yagi on 10m, band noise completely covers internal noise on my Yaesu. On  
the K2, I can hear the band noise, but the internal noise is rather more  
than I like. Even strong signals don't move the S meter much, and that is  
after I have tweaked the settings, and adjusted the AGC threshold.

I know audio filtering will help with this. I also did the mod to increase  
the gain of the RF preamp. I wonder if anyone else sees the 10m  
sensitivity as a problem? Is there perhaps a wider bandwidth transistor to  
use in place of the 2n5109?

NH7O