Power Cord - HP 120A Operating And Servicing Manual

Sect. I Page 2
sensitivity. The high sensitivity and de to 200 kc
bandwidth which is independent of sensitivity make the
120A useful for medical, geophysical, and industrial
applications.
Phase shift measurements can be made accurately
with this oscilloscope over a wide range of input fre ­
quencies. Relative phase shift between the vertical
and horizontal amplifiers is less than 2° at 100 kc.
is an offset, round pin added to a standard two-blade
ac plug which grounds the instrument chassis when
used with the appropriate receptacle. To use this
plug in a standard two contact outlet an adapter should
be used to connect the NEMA plug to the two contact
system. When the adapter is used the ground connec ­
tion becomes a short lead from the adapter which can
be connected to the outlet mounting box for the pro ­
tection of operating personnel.
1-2 DAMAGE IN TRAN IT
After unpacking this instrument should any shipping
damage become evident, refer to the ' ' Claim for Dam ­
age in Shipment " paragraph on the warranty sheet in
this manual.
1-3 POWER LINE VOLTAGE
The scilloscope, like other ^instruments, is shipp ­
ed from the factory wired for 115 volt ac line operation
unless otherwise specified in the order. However, the
instrument may also be operated from a 230 volt ac
line source if the proper conversion is made to the
power transformer. This conversion is simple, and
is described in the Maintenance section.
1-4 POWER CORD
The three conductor power cable supplied with the in ­
strument is terminated in a polarized three prong
male connector recommended by the National Elec ­
trical Manufacturer ' s Association. The third contact
CABINET AND RACK M UNTING
The Model 120A scilloscope is avaihble as a ca ­
binet mount for bench or portable use and as a rack
mount for installation in a standard 19 inch equip ­
ment rack. nly 7 inches of rack space is required
for the 120AR and it may be supported in the rack by
the front panel or on slides for easy withdrawal from
the rack. Since both models are electrically identical
and differ pnly in mechanical placement, this book
applies to both models.
The equipment slides are available only for the rack
mount model and at extra cost. They can also be in ­
stalled at the factory on special order under Specifi ­
cation No. 12001.
1-5 ACCE ORIE AVAILABLE
An AC-83A Viewing Hood is available at extra cost.
This is a face-fitting moulded rubber hood used to
shade the face of the cathode-ray tube under high am ­
bient light conditions. This will permit the use of
lower trace intensity setting which is important es ­
pecially with the phosphors susceptable to burning,
such as the P7. Information concerning other cath ­
ode-ray tube phosphors and their corresponding fil ­
ters will be found in the following table.