textronix scope display sine ghost shadow why lowlevel only

hewo

Member
2010-02-19 11:23 pm
My problem occurs when china digital signal generator dialed low, say 25mv ac sine 1khz and fed into scope.

Should I try telecaster signal into scope instead to reveal whether shadow ghosting sine scope displayed is a scope discrepancy instead of the china digital signal generator?

Problem arose after duration extended scope energized, generator too. Generator battery powered. But scope has dual channel and both reveal generator's shafow ghosting sine wave.
As generator level raised into whole volt upwards problem diminishes. Generator is small palm sized naked pcb with dc offset pot, level pot, navigation detent switches, display, bnc output two kinds, power switch, coaxial power socket
 

hewo

Member
2010-02-19 11:23 pm
Telecaster guitar pickup, stock, produces sine wave too, but it too is displayed on textronix 2215 sixty megahz gets shadow ghosting secondary waveform almost colinear to the primary sine displayed. Magnification of both axis required, sine tele pickups lowlevel.
Grounded scope input super focused and coherent.
But if scope magnifies both axis, either combinations, image gets incoherent.
So the china generator is fine.
And the scope needs repair on one or both axis image magnification.

Can I do this repair I have sevice manual but inexperience?
Or it's not worth repairing? considering china digital scope ebay palm sized cheap price ticket?