Re: 2465A channel 2 problems
When calibration is under computer control, the computertoggle quoted messageShow quoted text
will automagically set all of the pertinent controls to their
proper settings for you. If the inputs need to be 50 ohms,
they will be set to 50 ohms.
Just like the manual says.
If your preamp attenuators are broken, they won't do what
they are told to do, and calibration will fail.
Two quick ways to kill the attenuators are to give
them a spray with contact cleaner, or to wash them with
water. The manual warns you not to do either. Somehow
everyone knows better than the engineers that designed
The relays are not made to be water resistant, and will rust
solid if you wash them, and their plastic structure is not
guaranteed to be compatible with anything but isopropyl alcohol.
The relays are a latching variety that was devised and made by
tektronix. They are set or reset by giving the appropriate coil
a little pulse of current. They are not strong enough to release
if there is oil (contact cleaner) between the armature and the
pole piece. The surface tension will for all intents and purposes
glue them into one position.