[Elecraft] K1 K2 - Interesting noise

[Fred Jensen]

On 7/2/2011 1:50 PM, Phil Kane wrote:

>   How close and exposed was the rig to a medium or high power
>   radar installation?  Sounds like that (audio rectification).

None remotely close.  When it was still McClellan AFB, there was a shop 
in the corner which repaired mobile tactical radar equipment. 
Interstate 80 went over an overpass over the Union Pacific tracks there, 
and got just high enough to put my hearing aids into the bottom of the 
beam as I commuted to work.  It's an unmistakable sound, not what we 
were hearing.

You do trigger a possibility however.  I used to use my K2 for RTTY and 
had a problem with some sort of cross-coupling between the CAT cable and 
the audio to/from the computer and my headphones.  It sounded a lot like 
what we heard on Leviathan, and appeared to be N1MM polling the radio. 
It too sort of came and went some, and did not interfere with RTTY 
transmission or reception, just annoying in the cans.  I'm wondering if 
there is some connection to one or more data systems in the vault.

The solar array is very large, possibly the noise was associated with 
the charge controllers.  At any rate, I don't glow in the dark and Rich 
would have said something if he did, and the pulses we heard were not a 
series of prime numbers [alas, not ET, little, green or otherwise].  Our 
K1/K2's are fine.

>   until that radar was replaced by PavePaws at Beale AFB.

About 20 mi from me.  The radar feeds 520 peak watts each [individual 
PA's] to 1,760 antenna elements in a phased array antenna with about 37 
dBi gain in the 70cm band.  That's about 900 KW peak "real watts," and 
about 4.5 GW EIRP.  Those of us with 70cm repeater systems have had to 
take some draconian measures to comply with the USAF requests to lower 
our power at the radar.  At 4,586 megawatts EIRP, how come I've never 
heard it?

[That's a rhetorical question.  It's just mildly strange that we don't 
hear it]

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 2011 Cal QSO Party 1-2 Oct 2011
- www.cqp.org