[Elecraft] PX3 Problem?

[Don Wilhelm]

Dave,

The KX3 is designed to be operated with the preamp on most of the time. 
The only reason to turn it off is when extremely strong signals are 
encountered.

The preamp eliminates many spurious signals that are actually out of 
band due to its signal rejection "filtering".  That has nothing to do 
with the sensitivity, and it can kill extraneous results such as you are 
seeing.

If it makes those responses substantial with the preamp on, then there 
may be a problem to be addressed.

73,
Don W3FPR

On 7/16/2017 10:07 PM, Dave Sublette wrote:
> Good point.  However I am on 20 meters, which really doesn’t need the preamp.  Besides, the spikes are 40 dB high or so.  No, this behavior is definitely looking like a failure.  I have one more thing to try.  I will carry it out to the shop in my garage and plug it in.  If it is the same there as in here, it’s not any external influence.  Thanks for hanging in there with me.
> 
> 73,
> 
> Dave
>> On Jul 16, 2017, at 9:56 PM, Dale Boresz <dmboresz at gmail.com> wrote:
>>
>> Dave, make sure that the preamp is engaged on your KX3. If the preamp is off and you are receiving on a quiet band, you'll see "stuff" that would normally be covered by the band noise. Turn on the preamp, and the artifacts that you're seeing should be pushed below the noise floor of just about any band.