From: bill.sloman@ieee.org   
      
   On 3/12/2025 12:25 pm, Joerg wrote:   
   > On 12/1/25 8:48 PM, Bill Sloman wrote:   
   >> On 2/12/2025 5:05 am, Joerg wrote:   
   >>> On 11/29/25 9:38 PM, Bill Sloman wrote:   
   >>>> On 30/11/2025 6:17 am, Joerg wrote:   
   >>>>> On 11/29/25 3:38 AM, Bill Sloman wrote:   
   >>>   
   >>> [...]   
   >>>   
   >>>   
   >>>>>> There's nothing boring about EMC.   
   >>>>>   
   >>>>> After a dozen times of telling people not to use anodized aluminum   
   >>>>> for gear that needs to shield and they did it anyhow it does become   
   >>>>> boring. Then, explaining for the umpteenth time that split grounds   
   >>>>> do not work and that pigtail ground connections have close to zero   
   >>>>> effect at VHF and up.   
   >>>>   
   >>>> That's not EMC - that's just human stupidity. You need to hire a   
   >>>> primary school teacher (albeit one with electronics skills) and let   
   >>>> them handle those kinds of jobs.   
   >>>   
   >>> They do not know this. They see a metal enclosure and assume it's   
   >>> almost like a Faraday cage for RF. Yet it isn't, because of a tiny   
   >>> detail in the surface processing. I have met scores of seasoned   
   >>> engineers who did not know this. Except in defense-related companies,   
   >>> there everyone knew.   
   >>   
   >> Active RFI testing does make it obvious.   
   >>   
   >   
   > On a machine with half a zillion panels, not so easy. Yes, you can prove   
   > it but that involves lots of angle grinder use, noise, dust, people not   
   > liking you because of the noise and dust, machine shop time, cuts,   
   > bruises, metal splinters in the skin, et cetera. That got old over time.   
   >   
   >   
   >> Hunting for interference inside a machine is less well-structured, but   
   >> if you do it often enough you can eventually get to learn what to look   
   >> for.   
   >   
   > Sure but that gets old as well. Essentially you are always looking and   
   > finding other peoples mistakes and then have to find a very polite way   
   > to tell the crew. In Asia that can be especially delicate. "I found it   
   > is a good system. We could improve it a little by ...".   
   >   
   > IOW EMC work isn't very innovative. It's reactive.   
      
   That's one way of looking at it. If you begin a design with EMC in mind,   
   you can anticipate a lot of problems. If you have a nasty fast waveform   
   to ship around, making a it half of a balanced drive and shipping it   
   around with with its complement on shielded twisted pair (or paired off   
   in a ribbon cable) can make life a lot easier.   
      
   The junior engineers get the message fast if they see you making the   
   design messier and more extravagant than they would have done.   
      
   --   
   Bil Sloman, Sydney   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)