--- In TekScopes@y..., dhuster@p... wrote:
Bill,output amplifier. First thing to check is the collector load
go from the board up to the terminal post. If they're the beige,of
those resistors have an open winding, they'll be inductive, thegain
will be 'way low and the pulse response will be a HUGE ringing.Dean, thanks for your quick response. I m not sure which collector
load resistors you are speaking of but you mention them going from
the video output amp board to the terminal assy. so I assume you mean
the two 18 ohm resistors which couple the next to last output stages
(Q4478 & Q4468) to the final output stage drivers. These appear to be
OEM and measure 18 ohms as they should.
If you are referring to the collector resistors of the final stage,
they are 430 ohm wire wounds at 7 watts. The final coupling resistors
to the vertical plates are indeed TEK home grown which consist of a
200 ohm resister paralleled with a .3uh choke winding. These have
almost no DC resistance for obvious reasons. BTW, there are two
different versions of the TEK video output amplifier and I have the
discreet component version as you can probably tell by now.
As you suggested, I am looking at component values but haven't found
anything suspicious yet. Your help is appreciated.