[RFI] Broadband RFI...

[Jim Brown]

On Tue,5/31/2016 4:33 PM, Dave Cole wrote:
> I swear you have a paper on just about every subject of interest.  '

RFI/ EMC is a topic I started working on professionally around 2001. I'm 
still vice-chair of the AES Standards Committee Working Group on EMC, 
and am a principal author of all of our Standards on EMC. A lot of what 
I know came from hanging out with some of the other very bright guys in 
that WG.

> I am doing a bit of RF snooping already, using the P3 fed from the K3,
> which shows me plus and minus 100 KHz, not much but it has already shown
> that it is VERY unstable on startup, and as time passes, it stables
> down.  I will have some movies of this over the next few weeks or so,
> using a real SA.

Don't shortchange the P3 -- it is a REAL spectrum analzyer, and, if 
you've calibrated your K3, the P3 will also be calibrated. There are 
instructions in the K3 manual for doing amplitude calibration if you 
have a calibrated generator.

There are some settings and adjustments that make the P3 more powerful. 
First, always use averaging of the amplitude display, and at its maximum 
setting. This gets rid of all the random stuff and lets us concentrate 
on signals and electronic noise. Second, always keep the bottom of the 
display adjusted to the noise floor. This makes signals (and noise) far 
more visible. Third, set the Scale so that you see the relatively weak 
noise traces that we're looking for. Fourth, used "Fixed Tune Mode," so 
that averaging does not reset every time you tune. And for chasing 
noise, I usually use the widest setting (200 kHz).

Also, on the K3, set S-Meter to Absolute and turn the preamp on. This 
will maximize the sensitivity of the P3. I think there's also a setting 
for that in the P3 menu.

73, Jim K9YC