[Elecraft] Considering a K3

[Joe Subich, W4TV]

 > I have an inrad roofing filter installed to the PRO III.  Does this
 > still sound like Phase Noise to you?

Yes, phase noise in your 756ProIII.  The phenomena is called reciprocal
mixing - the phase noise from your own synthesizer appears on any strong
signal within the passband.

Icom rigs are known for terrible phase noise - I have a neighbor about
1/2 mile away whose transmitted phase noise and spurs from an Icom rig
and amp wipe out a substantial portion of any band he's on.

73,

    ... Joe, W4TV


On 4/5/2014 12:51 PM, David Cole wrote:
> Hi Dave (K6LL),
> Thanks for that thought, but I am pretty sure it is not their rigs...
>
> Here is my reasoning for why I think that:
>
> One rig is a K3, and an AL-1500, about 1/2 mile from me, and line of
> sight.  One of the the others is a 756 PRO III, and I don't know what
> amp, about a half mile from me, while the third is an older Collins rig,
> with an older Henry amp, about 100 yards from me.
>
> All three rigs, and my mobile rig in the driveway, cause exactly the
> same effect when they are transmitting, the band scope, (set to
> something like 200 KC wide), shows perfectly straight increase across
> the entire 200 KC's of scope, along the bottom, as a raised noise floor
> would.  It looks like phase noise, but I would expect that to roll off,
> and not be as flat as this is.  I also live close to an AM station,
> 100KW, and about a mile and a half away, and I see almost the same
> thing, as I approach the station frequency.  I can see the entire noise
> floor raise as I get closer to the station.
>
> I have an inrad roofing filter installed to the PRO III.  Does this
> still sound like Phase Noise to you?
>