Hello HP specialists and others ,
My 70001 mainframe has such powerfull fan's , (BEARINGS are OK!!!)
that the noise equals my Nilfisk Hoover (Brand name's , suppose you
all know what i want to point out)
Never had an instrument in my lab that has such a noisy fan.
Beeing designed for rack/industrial use, the noise is probably normal.
I noticed earlier 70001 instruments had NTC's to reduce the fan
voltage (and noise) , anybody has schematics or basic design that
was used ?
The printed circuit still has the unused space/circuit where the NTC
have to be located , I can see place for 2 ntc and 2 resistors (one
set for each fan ) and 1 in front probably for extra safety that used
to be there in earlier design .
The 70004 display mainframe that can be used together with the 70001
is designed very very silent ...
Many thanks,
Erik
