R7844
4 slot rackmount mainframe, designed around 1972. True dual beam.
400MHz. Distributed vertical deflection plates - a delay line of small
plates so the vertical deflection signal moves forwards along the
plates at about the same velocity as the electrons in the beam they are
deflecting.
R7704 rackmount 4 slot mainframe, also designed around 1972. ~175MHz. (Frequency response info is at the end of this page.)
7A19 x 2 vertical plugins. 50 ohm input, response to ~500MHz, depending on the mainframe. One has a variable delay line.
7A26 x 2 vertical
plugins. 1M input, dual input, so a single beam in the R7844 can
become a dual trace scope on its own. With two of these, the
machine has four traces.
7B85 delaying timebase.
7B80 delayed timebase.
These can operate independently, or the 7B85 can control when the 7B80
is triggered. The 7B85 can trigger the 7B80 after a given delay
(using a 10 turn pot) or it can enable the 7B80 to trigger itself once
from its own trigger source after this delay. The 7B85 has
another 10 turn pot which provides a second brighter spot range on the
trace (the delay system produces the first spot or range), for the
purpose of measuring elapsed time. The number is displayed on the
lower part of the screen when the digital readout system is turned
on. I have it turned off in the photos below, since its operation
detracts from beam 2 - it uses beam 2 intermittently to write the
numbers and letters at the top and bottom of the screen.
Type 585 valve oscilloscope,
designed in 1959. This is in Adelaide. We will pick it up
later this year. This has two plugins and a
Scope-mobile!
R1 0 (really, a few MHz minimum) to 500MHz.
R2 450MHz to 950MHz.
R3 900MHz to 1400MHz