Operation & Service Manual
Section IV
Model 1805B RF Control Unit
Testing
PERFORMANCE TESTING
The following paragraphs provide all the necessary information to verify that the TEGAM
Model 1805B is operating within its specifications as listed in Table 1-1. These tests can be
used as part of an incoming quality control inspection, as a periodic operational check, or
after maintenance or service has been performed.
INITIAL TEST SETUP
The following procedures establish the initial test setup for the Model 1805B. Listed below is
the necessary equipment to perform the setup.
MODEL
NOMENCLATURE
HP3458A
Digital Voltmeter, 8 1/2 digits
TEGAM SR1 - 100 ohm
100 ohm Resistance Standards (2)
TEGAM 1109
Feedthrough Thermistor Mount
a. Connect the two 100 ohm resistance standards in series and designate them RS1 and
RS2. Use the following method to obtain the dividing factor (DF):
(1) Measure total series resistance of RS1 and RS2 with a multimeter and make note
of measured value.
(2) Measure resistance of RS2 with an ohmmeter and make note of measured value.
(3) Calculate the dividing factor as follows:
RS1 + RS2
DF=
RS2
b. Connect the two resistance standards to the 1805B BIAS MOUNT terminals (E1 and E2)
and DVM terminals as shown below. If desired, link the Model 1109 Temperature CONTROL
connector (J1) to the 1805B Temperature CONTROL connector (J1) via a temperature
control cable (P/N 138-477).
c. Set 1805B RF ON/OFF switch (S2), located in the center of the front panel, to the OFF
position.
d. Turn 1805B POWER switch (S1), located on the bottom left side of the front panel, to
the STANDBY and ON positions ensuring that the proper LED’s (DS5 or DS4) illuminate.
Allow one hour for the feedthrough thermistor mount (TEGAM Model 1109) to stabalize.
DC SUBSTITUTION ACCURACY TEST
The following procedures will determine the accuracy of dc substituted power levels. Using
the initial test setup, proceed with the following steps:
4-4
