[net.audio] VDTs and their whines

alex@sdcsvax.UUCP (Alex Pournelle) (07/05/84)

I think the freq you're referring to is 15750 Hz, caused by the flyback
transformer--unless you have a very high-performance tube (color hi-res,
etc).  Many people "tune it out", whether they can hear it or not.  Some
of this noise is usual, a whole lot may be caused by a bad flyback (or
other driver section component).  "refer to qualified service
personnel", as they say, and ask 'em if they can quiet it down.

Alex

rfg@hound.UUCP (R.GRANTGES) (07/07/84)

[]
The trouble with "qualified service personnel" is that they
usually are unable to hear the 15+khz sound themselves and also 
lack any apparatus to detect and measure its amplitude. Result:
device comes back either "fixed" or NTF (No Trouble Found). In
either case its exactly as it was when you took it to them.
hound!rfg