Tektronix 491 Maintenance Manual page 6

Characteristic
Dispersion
M H z / D I V R A N G E
Range
Accuracy
Linearity
k H z / D I V R A N G E
Range
Accuracy
Linearity
Resolution
IF Center Frequency
C o n t r o l R a n g e "
1 kHz/DIV to 500 kHz/DIV
Dispersion
0.2 MHz/DIV to 5 MHz/DIV
10 MHz/DIV
IF Attenuation
Range
Accuracy
IF GAIN Control
Range
Display Flatness with IF CENTER
FREQ at 000
Incidental FM
IF
IF + LO
Phase Lock
Internal Markers
INT REF FREQ Range
Stability; Ref. Osc.
(Short term FM)
External Phase Lock
Reference Input
Frequency
Voltage
Display Functions
Dynamic Range
L O G
L I N
S Q L A W
Maximum Input Power
1-2
ELECTRICAL CHARACTERISTICS
Performance Requirement
.2 MHz/Div to 10 MHz/Div
See Table 1-2
±3% (over an 8 division display)
1 kHz/Div to 500 kHz/Div in a 1-2-5 se-
quence and zero dispersion.
±3% of each setting
±3% (over an 8 divisions display)
≤1 kHz to ≥ 1 0 0 k H z ; i n 1 1 u n c a l i b r a t e d
steps.
I F C E N T E R F R E Q
≥ ( + and – 2.5 MHz) ≥ ( + and – 50 kHz)
≥ ( + and – 25 MHz) ≥ ( + and – 1 MHz)
≥ ( + and – 10 MHz) ≥ ( + and – 1 MHz)
0 to 51 dB
±0.1 dB/dB
≥ 5 0 d B
3 dB maximum amplitude variations from
10 MHz to 12.4 GHz.
6 dB maximum amplitude variations from
12.4 GHz to 40 GHz
≤ 2 0 0 H z
≤ 3 0 0 H z ( a t L O f u n d a m e n t a l a n d w i t h
phase lock operation)
1 MHz ±0.1% (Control next to OFF posi-
tion.)
At least 1 kHz but not more than 1.3 kHz
above measured frequency with the INT
REF FREQ control counterclockwise (next to
OFF position.)
≤ 1 p o r t i n 1 0
7
.
1 MHz to 5 MHz
1 to 5 volts peak to peak.
≥40 dB with 8 division display
≥26 dB with 8 division display
≥13 db with 8 division display
- 3 0 d B m f o r l i n e a r o p e r a t i o n
+15 dBm diode mixer, power limit
(cont)
S u p p l e m e n t a l I n f o r m a t i o n
In a 1-2-5 seauence
Over the ±2.5
CENTER FREQ control. Measured over the
center 8 divisions of the graticule.
May be coupled with the DISPERSION con-
trol or switched separately.
F I N E
In combinations of 1, 2, 4, 8, 16 and 20 dB.
Band 1 (10 MHz to 275 MHz) 50 MHz dis-
persion.
Bands 2 through 8 (275 MHz to 40 GHz]
100 MHz dispersion.
Typically 100 Hz. Up to 400 Hz if power
line frequency drops to 48 Hz.
Instrument must be inside the dust cover.
See Fig. 2-8
MHz range of the IF