Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > sci.electronics.design > #464595

Re: EMI problems

Show all headers | View raw

On 2017-06-15 12:57, Lasse Langwadt Christensen wrote:
> Den torsdag den 15. juni 2017 kl. 21.47.56 UTC+2 skrev John Larkin:
>> On Thu, 15 Jun 2017 12:27:25 -0700, Joerg <news@analogconsultants.com>
>> wrote:
>>
>>> On 2017-06-14 16:09, John Larkin wrote:
>>>>
>>>>
>>>> I designed this little photodiode amp and I'm trying to measure its
>>>> output noise. All we can see on a spectrum analyser is radio and TV
>>>> stations.
>>>>
>>>> https://dl.dropboxusercontent.com/u/53724080/Otis/EMI/Sutro.JPG
>>>>
>>>
>>> Who installed those vents? Did they smoke some funny-smelling cigarettes?
>>
>> That's the roof of the San Francisco Ballet School. Artsy types.
>> Sometimes I can hear them practising. One of my engineers dances
>> Flamenco there, conveniently next door.
>>
>>>
>>>
>>>> The *output* of the amp needs to be around 10 nV/rootHz.
>>>>
>>>> The DUT output is 100 ohm differential, which makes it harder. So we
>>>> took one of our standard products, an x100 1GHz amplifier, and hacked
>>>> a wideband transformer into the front end. Then I stuffed the DUT and
>>>> the X100 amp into a custom-machined shielded enclosure.
>>>>
>>>> https://dl.dropboxusercontent.com/u/53724080/Bypassing/E2_EMI_Encllosure.JPG
>>>>
>>>> The DUT is the smaller extruded box. There's enough gain that I can
>>>> use a scope to measure RMS noise voltage directly.
>>>>
>>>> Those are really nice shield cans, but before you can use them you
>>>> have to find a way to dispose of the filler materials that they come
>>>> with.
>>>>
>>>
>>> If you want a nice-looking smaller box there is also Fishermen's Friend.
>>> You can get cans with a more international flair:
>>>
>>> https://en.wikipedia.org/wiki/Fisherman's_Friend#/media/File:Fisherman%27s_Friend_Tin_Taiwan.jpg
>>>
>>> Be careful. The dad of a friend popped one and then fell asleep on the
>>> couch. When he woke up the cheek pointing towards the pillow had become
>>> numb like after a major dentist session.
>>
>> Some people like the Altoids cans for small stuff.
>>
>
>
> https://www.adafruit.com/product/16
>
> https://www.adafruit.com/product/97
>

Much cheaper in regular retail packaging and then you get the mints in 
there "for free":

https://www.walmart.com/ip/Altoids-Wintergreen-Mints-1.76-oz/38253375

-- 
Regards, Joerg

http://www.analogconsultants.com/

Back to sci.electronics.design | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

EMI problems John Larkin <jjlarkin@highland_snip_technology.com> - 2017-06-14 16:09 -0700
  Re: EMI problems Martin Riddle <martin_ridd@verizon.net> - 2017-06-14 20:05 -0400
    Re: EMI problems John Larkin <jjlarkin@highland_snip_technology.com> - 2017-06-14 18:01 -0700
      Re: EMI problems o pere o <me@somewhere.net> - 2017-06-15 09:28 +0200
        Re: EMI problems Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-06-15 10:59 -0400
          Re: EMI problems Don Kuenz <g@crcomp.net> - 2017-06-21 02:53 +0000
        Re: EMI problems John Larkin <jjlarkin@highlandtechnology.com> - 2017-06-15 07:59 -0700
          Re: EMI problems George Herold <gherold@teachspin.com> - 2017-06-15 08:07 -0700
            Re: EMI problems Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-06-15 11:12 -0400
              Re: EMI problems George Herold <gherold@teachspin.com> - 2017-06-15 08:42 -0700
            Re: EMI problems John Larkin <jjlarkin@highlandtechnology.com> - 2017-06-15 09:38 -0700
          Re: EMI problems Robert Baer <robertbaer@localnet.com> - 2017-06-16 22:06 -0800
  Re: EMI problems Jon Elson <jmelson@wustl.edu> - 2017-06-15 14:14 -0500
    Re: EMI problems John Larkin <jjlarkin@highland_snip_technology.com> - 2017-06-15 13:55 -0700
      Re: EMI problems Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-06-15 14:02 -0700
      Re: EMI problems Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-06-16 12:43 -0400
        Re: EMI problems John Larkin <jjlarkin@highland_snip_technology.com> - 2017-06-16 10:11 -0700
          Re: EMI problems Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-06-16 13:24 -0400
      Re: EMI problems Jeff Liebermann <jeffl@cruzio.com> - 2017-06-16 10:37 -0700
      Re: EMI problems Jon Elson <jmelson@wustl.edu> - 2017-06-16 13:31 -0500
        Re: EMI problems Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-06-16 14:46 -0400
          Re: EMI problems John Larkin <jjlarkin@highland_snip_technology.com> - 2017-06-16 12:25 -0700
          Re: EMI problems George Herold <gherold@teachspin.com> - 2017-06-16 13:07 -0700
        Re: EMI problems John Larkin <jjlarkin@highland_snip_technology.com> - 2017-06-16 12:22 -0700
    Re: EMI problems upsidedown@downunder.com - 2017-06-16 09:35 +0300
      Re: EMI problems John Larkin <jjlarkin@highlandtechnology.com> - 2017-06-16 06:40 -0700
  Re: EMI problems Joerg <news@analogconsultants.com> - 2017-06-15 12:27 -0700
    Re: EMI problems John Larkin <jjlarkin@highland_snip_technology.com> - 2017-06-15 12:47 -0700
      Re: EMI problems Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-06-15 12:57 -0700
        Re: EMI problems Joerg <news@analogconsultants.com> - 2017-06-15 13:12 -0700
      Re: EMI problems Joerg <news@analogconsultants.com> - 2017-06-15 13:03 -0700
    Re: EMI problems "Lund-Nielsen, Jorgen" <jorgen.lund-nielsen@xyz123desy.de> - 2017-06-16 08:58 +0200
  Re: EMI problems Jeff Liebermann <jeffl@cruzio.com> - 2017-06-16 10:03 -0700
    Re: EMI problems John Larkin <jjlarkin@highland_snip_technology.com> - 2017-06-16 11:09 -0700
      Re: EMI problems Jeff Liebermann <jeffl@cruzio.com> - 2017-06-16 12:06 -0700
        Re: EMI problems John Larkin <jjlarkin@highland_snip_technology.com> - 2017-06-16 12:34 -0700
          Re: EMI problems Jeff Liebermann <jeffl@cruzio.com> - 2017-06-17 09:22 -0700
            Re: EMI problems John Larkin <jjlarkin@highlandtechnology.com> - 2017-06-17 10:08 -0700
              Re: EMI problems John Larkin <jjlarkin@highlandtechnology.com> - 2017-06-17 11:07 -0700
                Re: EMI problems Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2017-06-17 21:30 +0300
                Re: EMI problems pcdhobbs@gmail.com - 2017-06-17 16:34 -0700
                Re: EMI problems krw@notreal.com - 2017-06-17 20:44 -0400
                Re: EMI problems George Herold <gherold@teachspin.com> - 2017-06-19 06:03 -0700
              Re: EMI problems Jeff Liebermann <jeffl@cruzio.com> - 2017-06-18 12:49 -0700
                Re: EMI problems John Larkin <jjlarkin@highlandtechnology.com> - 2017-06-18 13:42 -0700
                Re: EMI problems Jeff Liebermann <jeffl@cruzio.com> - 2017-06-18 15:50 -0700
                Re: EMI problems John Larkin <jjlarkin@highlandtechnology.com> - 2017-06-18 17:15 -0700
                Re: EMI problems upsidedown@downunder.com - 2017-06-19 09:39 +0300
                Re: EMI problems upsidedown@downunder.com - 2017-06-19 09:48 +0300
                Re: EMI problems Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-06-19 12:45 -0400
    Re: EMI problems "John Miles, KE5FX" <jmiles@gmail.com> - 2017-06-16 15:30 -0700
      Re: EMI problems John Larkin <jjlarkin@highland_snip_technology.com> - 2017-06-16 18:10 -0700
        Re: EMI problems Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-06-17 11:08 -0400
      Re: EMI problems upsidedown@downunder.com - 2017-06-17 14:25 +0300
      Re: EMI problems Jeff Liebermann <jeffl@cruzio.com> - 2017-06-17 09:35 -0700
        Re: EMI problems John Larkin <jjlarkin@highlandtechnology.com> - 2017-06-17 10:42 -0700
  Re: EMI problems upsidedown@downunder.com - 2017-06-17 14:45 +0300
    Re: EMI problems John Larkin <jjlarkin@highlandtechnology.com> - 2017-06-17 08:28 -0700

csiph-web