[Elecraft] K3 TX spurs?

[Scott Ellington]

During the recent NAQP, I heard these 1 kHz sidebands on a nearby station's signal on 160.  (Perhaps the same station Ken heard?)  It turns out, his K3 was overloading his wimpy power supply, and making it go into current limit.  There was no sign of the spurs at slightly lower power.  He could see fluctuations in the supply voltage on the K3 internal meter whenever the spurs appeared.  With an adequate power supply, of course, the K3 is very, very clean.

By the way, while we were checking that out we did a quick comparison of key clicks from my K3 and FT-1000D (with the W8JI mods).  The K3 was much better.  And I know the FT-1000D was much worse before the mods.   It is best to have neighbors with K3's.  (But with good power supplies.)

73,

Scott  K9MA


On Jan 18, 2011, at 12:40 PM, Rose wrote:

> I think I recall a thread about spurs being produced by 
> a K3's TX, but didn't pay enough attention at the time.
> 
> I've since become aware of a K3 that appeared to have 
> two spurs showing up on my P3.  They were about 30db 
> down from his very strong carrier on 7031 KHZ, and equally 
> spaced about 1 KHZ on either side. They both could be 
> "tuned in" and copied as individual signals.  I was surprised 
> when I asked the fella what his rig was and he told me it is a 
> K3. (;-)
> 
> I have -not- seen these spurs appear on other strong signals
> since this event, and follow-up tests with him have not shown
> the spurs ... but ... I've not seen his signal as strong as it was
> at the time.
> 
> There's no doubt they were "real", but what might be the
> cause?  Is / was the problem with his K3, my K3 or my P3.
> 
> Thoughts?
> 
> 73! 
> 
> Ken Kopp - K0PP
> ElecraftCovers at gmail.com 
> ______________________________________________________________
> 

Scott Ellington
Madison, Wisconsin
USA