[Elecraft] K3 diversity phase drift

[David Gilbert]

Yes, I agree ... the slow drift wouldn't cause problems for normal 
diversity reception.  That's pretty much a real time process.  I've had 
my K3 since 2008 and never even noticed it before.

It's not really even a deal breaker for my arrival angle application 
since in my tests I'm seeing LOTS of other weird effects that have a 
much greater effect and at this point appear to be due to various 
multipath phenomena ... some obviously due to propagation but also 
apparently due to near field ground reflections as well as more distant 
terrain reflections.  Maybe even some interactions with my other 
antennas about 100 feet away, although I've purposely done tests at 
frequencies far from their resonance.

The application itself works great to be honest, but it looks like real 
world effects are going to constrain it from working like I had 
originally hoped.  Sometimes the incoming wave fronts are stable and 
apparently planar, but at other times it is obvious that is far from 
being the case.  The app operates in a browser on my website (free) and 
I'm working on a YouTube description for anyone who might want to play 
with it.  I've mostly been using it for tracking the elevation arrival 
angle of WWV (really narrow filter on the K3 to eliminate the WWV 
sidetones) using horizontal dipoles, but I designed it to also work for 
azimuth using vertical antennas and it would possibly have fewer 
anomalous effects in that mode ... but maybe not.  ;)

73,
Dave  AB7E


On 4/8/2026 11:55 AM, Jim Brown via Elecraft wrote:
> Interesting observation, Dave. For use in diversity reception, I don't 
> see any practical problem with the drift -- the difference would only 
> affect the depth of cancellation if the two ears were combined to 
> mono. But diversity works by our ears getting the output of two 
> antennas spaced a significant fraction of a wavelength and/or having 
> different polarization and our brains listening to the one where 
> cancellation between multiple arrivals is least at any given moment in 
> time.
>
> 73, Jim K9YC
>
>  On 4/8/2026 11:20 AM, David Gilbert via Elecraft wrote:
>> The amount of the drift varies but is roughly 3 degrees in about ten 
>> minutes.  It seems to be pretty steady even when the K3 has had a 
>> chance to warm up, with a little bit of jitter (a few hundredths of a 
>> degree or so) as it drifts.
>>
>> I'm just curious what might be the source of the drift.  Any thoughts?
>
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