HP 4934A User Manual

Attenuation Distortion
Attenuation distortion defines the flatness and usable bandwidth of the cir¬
cuit.
1 The transmitter usually sends 1004 Hz at the nominal data level. The level
received at this frequency is set as the reference level.
2 The transmitter is stepped through a range of spot frequencies over the channel
bandwidth. At each frequency, the receiver displays the difference between the
level at the reference frequency and the level received.
Gain Slope
This is a quick method for assessing the flatness of a channel using only
three frequencies, two of which are close to the edges of the channel band¬
width. The level measured at 1004 Hz is the reference level; then the attenu¬
ation is measured at 404 Hz and 2804 Hz relative to the reference level.
Frequency
Frequency shift can occur over facilities such as FDM carrier systems and is
measured by comparing the frequency sent into the channel with the fre¬
quency received at the far end of the channel.
N OT E The calculation of frequency shift may not be valid when measured on looped-around
carrier facilities since the frequency shift in one direction may be canceled by
frequency shift in the return direction.
2-6 Making Measurements

HP 4934A Specifications

General

Brand	HP
Model	4934A
Category	Measuring Instruments
Language	English