HP 5314A Universal Counter
The HP 5314A is desktop portable 7 digits 100 MHz / 100 nsec universal counter. The counter has seven functions performance, overflow indication and input signal conditioning.
The seven functions are: frequency measurement, singleshot period, period average, time interval, totalize, ratio, and
self check. The input signal is AC coupled and fully conditioned as follow: slope selection, trigger level and attenuation.
The HP 5314A has been produced by Hewlett Packard with two options:
option 001  Temperature Compensated Crystal Oscillator (TCXO)
option 002  battery pack for portable operation
Input characteristics 
Channel A: 10 Hz to 100 MHz
Channel B: 10 Hz to 2.5 MHz
sensitivity 25 mV rms
coupling AC
impedance 1 MΩ
attenuator (Ch A only): X1 or X20

Frequency (A) 
range 10 Hz to 10 MHz direct count or 1 MHz to 100 MHz prescaled by 10
LSD displayed: 0.1 Hz, 1 Hz, 10 Hz switch selectable

Period (A) 
range 10 Hz to 2.5 Mhz
LSD displayed: 100 nsec/N, where N=1 to 1000 in decade steps of N

Time Interval (A) 
range 250 nsec to 1 sec
LSD displayed: 100 nsec

Ratio 
range: 10 Hz to 10 MHz Channel A and 10 Hz to 2.5 MHz Channel B
LSD displayed: A / B x N in decade steps of N, for N = 1 to 1000

Totalize (A) 
range: 10 Hz to 10 MHz
resolution: ±1 count of input

Time Base 
frequency: 10 MHz
aging rate: <3 parts in 10^{7} per month
TCXO (opt. 001) aging rate: <1 parts in 10^{7} per month

