The
last
evolution
in
the
50s
of
the
signal
sources
product
line
would
be
the
211A
square
wave
generator
introduced
in
the
Hewlett-Packard
Journal,
May,
1955,
volume
6,
number
9.
Main
specifications
were:
Continuous
frequency
coverage
from
1
cps
to 1
mc.
Output
7
Volts
across
75
ohms
or
55
Volts
peak-to-peak
across
600
ohms
with
a
rise
time
of
20
milli
micro seconds
(as
noted
in
the
specifications
listing
-
Rise
time
value
expressed
in
nanoseconds
was
not
yet
a
current
practice
in
1954)
Thanks
to a
long
time
VTA
Replication
project
supporter
for
this
information.
