[time-nuts] Thunderbolt - any negatives ?
w9ac at arrl.net
Fri Jun 19 16:38:17 UTC 2009
> "The other issue is noise from a switcher."
And be mindful that some frequency-standard devices contain integrated DC-DC
switching converters -- like my HP 58540A GPS-DO. The noise from the HP DC
converters was spraying RFI every 100 kHz or so on the HF bands. After
trying various RFI abatement measures, including additional bypass C and
toroid-wound #31 ferrite material, my solution was scrap the entire PS board
and bring in clean power from a triple-output linear supply made by
Power-One. There's no switch-mode component anywhere in the path of my
I love switch-mode devices for their light weight and package density; I
hate them for their propensity to generate RFI and at least historically,
their abysmal long-term reliability. That said, I do believe that recent
SMPS product is significantly more reliable than those manufactured 10+
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