[Elecraft] K3S Enable Preamp 2 Without Preamp 1

[Jim Brown]

On 4/6/2018 5:58 PM, john at kk9a.com wrote:
> I have operated from several countries using my K3S and I am never so
> fortunate to have a noise floor low enough use preamp 2. Most of the time
> preamp 1 is also off.

I've had the opposite experience. MDS of the original K3 was woefully 
poor above 15M, even with the preamp switched in. As luck would have it, 
I have a very nice ARR GAsFET 6M preamp on the shelf that I'd used in 
Chicago that I inserted at the RX antenna patch point; I found that it 
improved the MDS all the way down to 12M. I would have missed a LOT of 
QSOs without that preamp. Of course, like everyone else, sometimes my 
noise level is lower than at other times, and a solar system 500 ft from 
my main antenna raises it by 10 dB on 10 and 6 when the sun is hitting it.

When the K3S was introduced, I quickly replaced the Synth boards and the 
Transverter board to get that improved preamp, simplifying my RX antenna 
switching. I do find, though, that the GAsFET preamp has a slightly 
lower NF, so I continue to use it during the 6M season.

73, Jim K9YC