[aprssig] CFL Bulbs and Shack backup power ;-)
kc6ete at gmail.com
Sun Jun 5 15:39:34 EDT 2011
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...
>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
>> 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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