HP 6611C Power Supply, too noisy?

[ElektroQuark]

I thought I post about this a couple of weeks ago but can't find the post 
So here it is againb.

I have just pruchased a HP 6611C System Power Supply.
It works,  andit looks likes it's caliobration is fine, buit is somewhat noisy and I don't know if it is normal for this type of suply.

At power up there is a noise from... the transformer? Like a "powmmmmmm".
Then, the noise is covered by the fan noise.

Is that commond for this units?

[twam]

Had the same thing on my 6612C.

[dom0]

Thumping is quite normal with larger transformers.

[ElektroQuark]

Somehow I missed those answers.


Thank you very much.

[SharpEars]

I thought I post about this a couple of weeks ago but can't find the post 
So here it is againb.

I have just pruchased a HP 6611C System Power Supply.
It works,  andit looks likes it's caliobration is fine, buit is somewhat noisy and I don't know if it is normal for this type of suply.

At power up there is a noise from... the transformer? Like a "powmmmmmm".
Then, the noise is covered by the fan noise.

Is that commond for this units?

I've got it's ultra-rare red-headed step child cousin, the 6611C-J05 and aside from a fairly loud turn-on thump (like you just turned on the power for a small city ), it also has a very VERY audible 60 Hz hum while operating. This is a bit masked by the fan, but you can always hear it, especially at low load when the fan spins down.

By the way, you probably should not try to calibrate the thing, if your spelling of the word caliobration (sp) is any indicator of your ability to calibrate  .