[aprssig] CFL Bulbs and Shack backup power ;-)

[Dave]

Nope. Made here 50' behind my office.

Dave <dave at g8kbv.demon.co.uk> wrote:

>Then your proven and compliant design goes off to China for "production 
>engineering", then made in the cheapest way posible, like with no EMI 
>filters.  It happens!  There are many PC PSU's in the UK (and other 
>consumer electrical crud) bought in good faith from well known retailers, 
>that nave no EMI filters in them.  The traces are there, but the "Filter" 
>is two wire links.
>
>Yet they all carry the appropriat CE, TUV, FCC compliance marks etc.
>
>Commercial EMC testing (Emmissions) is purely to protect the broadcast 
>services.  If your product comes in well under those limits, well done 
>indeed.  But will the retail version when it's built overseas in bulk?
>
>Who checks the imported products?   No one!
>
>And as for PLT, sheesh...
>
>Take care.
>
>Dave G0WBX
>
>
>
>On 3 Jun 2011 at 17:53, david vanhorn wrote:
>
>> 
>> 
>> WOOT! Off topic a bit, but if there's anyone who will understand, it's
>> you guys.
>> 
>> Our new system is essentially unobservable on radiated emissions from
>> 100kHz to 7 GHz, except when transmitting, and even then the only
>> thing we see is carrier and 3rd harmonic which is lower than -45dBc.
>> 
>> Conducted is measurable, but more than 30dB below limits at the worst
>> points.
>> 
>> EFT test ( very nasty high speed relay chatter noise) > 4500V, the
>> test system started crashing before we failed.
>> 
>> This is an ARM processor at 48 MHz, and a 2.4 GHz radio on a two layer
>> board. No shielding or special filtering, beyond good layout and
>> appropriate bypass caps.
>> 
>> 
>> Radiated immunity maxed out the ability to generate signals, >50V/m
>> from 1 MHz thru 1GHz, and >192V/m in some spots (limited by capability
>> to generate power) Radiated immunity was done with simply the PCB in a
>> plastic holder, without the usual metal enclosure. Sanity check,
>> fluorescent tube in the GTEM lights nicely during the radiated test.
>> 
>> I'm guessing that you could have a houseful of these things, and never
>> know it on your radios, and never worry about them going nuts when you
>> key up.
>> 
>> (happy dance....)
>
>
>
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