Re: x-y on 551, 555 or 556 Dual Beam Scopes

Fabio Trevisan

Hello Bob,
I'm not familiar with the 5xx series, but, in general, the DC voltages
required by the CRT to drive the vertical deflection plates and horizontal
deflection plates are different, basically because the vertical plates are
ahead of the horizontal ones in the acceleration path of the beam.
I'm not sure as well, but I think that the horizontal plates, being located
at a point where the beam is running faster, they are less sensitive and
requires more signal amplitude than the vertical plates, for the same
It doesn't seem to me that it would make a great X-Y display, at least, not
without some tweaking of the second vertical amplifier, to adjust its
output to the horizontal plates requirements...
But that's all IMHO... I'm pretty sure there are people here that can tell
for sure.

On May 21, 2017 2:49 PM, "bob@... [TekScopes]" <
TekScopes@...> wrote:

The 551, 555 and 556 scopes have separate vertical amplifiers. I wonder if
it would be feasible to get an x-y display on say the upper beam by simply
connecting the output of the lower vertical amplifier to the CRT pins for
the upper beam horizontal deflection plates.

The only reference in the manual to x-y operation that I could find, is the
suggestion to use the external horizontal input but this is limited to low

I thought I would ask before I try this!

Possibly some phasing as in the 536 would be needed to make it perfect, but
the two vertical amplifiers are substantially identical.


Bob Krassa ACØJL

[Non-text portions of this message have been removed]

Posted by: bob@krassa. <bob@...>com

[Non-text portions of this message have been removed]

Join to automatically receive all group messages.