Elenco Wide Band RF Generator - Manual (Page 6)

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1. Preparation
(1) Set the POWER switch to the OFF position.
(2) Connect the AC plug to the AC supply.
(3) Connect the RF output leads to the OUTPUT terminals.
(4) Set the FINE control to the center position and the RF slide switch to the LOW
position.
(5) Set the FREQ RANGE switch at the operating band and rotate the frequency dial
knob to the desired frequency.
2. Connections
The RF leads are connected to the input of the circuit under test. The red terminal is at
high potential, or “hot”, and the black is at earth potential for chassis protection.
For the RF signal at the receiver antenna input, connect a 50 to 200
W
resistor, 1/4W, in
series. When checking sets with a rod antenna, connect leads to a coil with a few turns
of wire and couple the coil to the antenna.
In checking RF and IF amplifier circuits, connection should be made through a small
capacitor, 1-5pF, in order to prevent detuning effects.
NOTE: When connecting directly to the input circuit, make certain that there is no high
DC voltage present. Otherwise, connect a blocking capacitor, 0.05
m
F - 100pF, depending
on the frequency.
7. AF Output, 1kHz
Control settings:
Mode switch at INT. MOD. position.
FREQ RANGE switch at “F” and frequency dial at 100MHz.
Connect the leads from the OUTPUT to the test circuit.
Use an external
potentiometer, 100k
W
- 1M
W
, to lower the voltage.
8. Oscillator Frequency Calibration
The RF oscillator frequency can be calibrated to a high degree of precision using the
harmonics of the internal crystal oscillator and an external all-wave receiver. The
latter is utilized as a frequency transfer unit.
(1) Set the mode switch at XTAL.
(2) Insert the “standard frequency” crystal, preferably at a multiple of 1MHz. For
spot frequency checking, at say 10.7MHz, use a 10.7MHz crystal.
(3) Set the RF slide switch at LOW.
Adjust the FINE control as required.
(4) Connect the RF output to the receiver input, direct or through a small coupling
capacitor to the rod antenna.
OPERATION