131

1301 26 Aug 67

Ran 46 K of BLTST for 8 hrs 15 min.
No errors reported.
SRR

1300 25 Aug 67 (out of temporal order)

Investigated DECTAPE noise sensitivity.

Found that transients from turning
teletypes on and off were indeed making
30 mv spikes on the timing track lines.
These spikes also make spurious
fuming pulse output as expected.

Investication of teletypes circuit
shows no surpression of
inductive surges when breaking
110 vac line.

I suggest the installation of
.01 mfd, 600 V mylar caps across
line switch. of all TTY's.

The noise pickup on DECTAPE
head lines is present on
at leaset 2 of the data tracks also

The noise picked up is reduced
very little by unplugging control
and head lines at the between
the first and second dual units.
SRR