This is not for filtering. The L manual says:
"Low-frequency peaking for the X10 amplifier is provided mainly by
C6002A and C6002B in the plate circuits of V5942 and V6042. With
their associated resistors, these capacitors form a low-frequency
boost network to compensate for the low-frequency attenuation
introduced in the cathode circuits, the screen circuits, and the RC
coupling network between the Second amplifier and the Second cathode
follower. ... the amount of attenuation can be varied with the LOW
FREQ. ADJ. control in the grid of V6132."
This technique is discussed in detail in "Typical Oscilloscope
Circuitry."
Larry Christopher
--- In TekScopes@..., "morriso2002" <vilgotch@...> wrote:
I'm not sure what you mean by the big honking filter cap in the L.
It
certainly has quite comprehensive decoupling of the B+ to the low
level amps which is pretty standard practice. I'm too lazy to get
out
my L to check, but that's almost certainly what it's for. That
quite
a high gain wideband amplifier and keeping such devices stable is
not
a trivial design task!
