Table of Contents
Advertisement
Calibration
The following information, based on abstracts from the Company Test Schedule,
is intended to enable you to carry out a series of tests by which the main points of
performance of the instrument can be checked; it also gives details concerning adjust-
ment to preset components and the choice of value for individually selected components.
5.1
APPARATUS REQUIRED
(a)
Resistance bridge,
e .. g.
mT
type TF 2700.
'(b)
Signal generator, 400 MHz and 1 GHz, 50
Q
output; e.g.
mf
types TF 801
and TF 1060.
(c)
V. S. W. R. measuring device, 50
Q
characteristic impedance with residual
v. s. w. r. of better than 1. 01 at 1 GHz.
(d)
Variable a. c. source, capable of delivering 10 W; e. g. a Variac.
(e)
Dynamometer wattmeter, 0 to 10 W, 0.5%.
5.2 PRELIMINARY CHECKS
(Apparatus required: item
a)
NOTE:
When carrying out these checl{s, it is advisable to set the Range switch
to 10 W to avoid the possibility of overloading the meter.
1) . Connect the termi,nating load and measure the ·cold d. c. resistance of the
terminating load (R4) between the centre and outer conductors of the socket (SKTB).
The resistance should be 49
Q
±2%.
2)
Measure the resistance of the complete power meter (i.e. , in-line detector
and the terminating load) between the centre conductor of the input socket SKTA and
chassis.
The resistance should be 53
Q
±3%.
5.3 STANDING WAVE RATIO
(Apparatus required: items b and
c)
For the power meter to act as a good match to a transmission line its v. s. w. r.
must be as close to unity as possible.
In the TF 2502, v. s. w. r. is a function of the
2502 (1a)
17
Advertisement
Table of Contents
