Circuit Description - HP 460A Operating Manual

of rise will be approximately 3. 7 millimicroseconds and for three
stages, the time of rise will be approximately 4.4 millimicro-
seconds.
1-5 CIRCUIT DESCRIPTION
The Model 460A is a new type amplifier which has a very wide
transmission band. It has two stages with five tubes in the first
stage and seven tubes in the second stage. The grids of these
tubes are connected along one transmission line for the input cir-
cuit and the plates of the tube s are connected along a second
transmission line for the output circuit. A wave traveling down
the input line excites the grids in succession and half of the cor-
responding wave generated in the plate circuit travels down the
plate line toward the output and is reinforced at each successive
plate. The part of the wave in th plate line which travels in the
reverse direction is absorbed by a termination of the other end of
that line. By the time the wave in the plate line reaches the out-
put, it has been amplified by about 10 db. The second stage adds
another 10 db to make a total of 20 db gain for the unit.
The Model 460A will amplify pulses with an extremely short rise
time and with vi tually no overshoot. The time of rise of the
amplifier itself is approximately 2.6 millimicroseconds. The
amplifier has an amplitude response closely matching the Gaussian
Curve, which is the ideal transmis sion for pulse amplifications
when ringing or overshoot cannot be tole=ated.
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