Elenco Wide Band RF Generator - Manual (Page 7)

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5. Unmodulated Carrier
Set the mode switch to the EXT. MOD. position. There should be no connection to the
INPUT.
The RF signal can be used in testing a receiver equipped with a beat oscillator, or
circuits that do not require a modulated signal.
The RF signal can be applied to a sweep generator for the marker signal.
6. Crystal Oscillator Output
Control settings:
Mode switch to the XTAL position. Insert a crystal in FT-243 holder in the XTAL
socket.
RF output switch at LOW.
FREQ RANGE switch at “F” and frequency dial at 100kHz.
FINE control at minimum.
The output signal is treated in the same manner as for the unmodulated carrier with
the exception that the output level cannot be adjusted.
In certain calibration procedures a short lead near the test circuit will provide sufficient
coupling.
NOTE: If an RF signal is required at the same time, set the frequency with the FREQ
RANGE switch and frequency dial as required. Adjust the RF FINE control.
3. Modulated Carrier, Internal Source
Set the mode switch at INT. MOD.
By tuning the receiver to the generator frequency, or vice-versa, an audio tone will
be heard in the loudspeaker. An audio voltmeter should be connected across the
speaker terminals when aligning the internal circuits.
A dummy resistor with
suitable power rating can be used in place of the moving coil.
It is advisable to keep the RF signal level as low as possible in order to prevent
overloading the transistors or election tubes in the circuit. Excessive input voltage
will cause AGC action and/or two resonance points to appear and proper
alignment or adjustment would be impossible.
4. Modulated Carrier, External Source
Set the mode switch to the EXT. MOD. position.
Connect the leads from an external audio generator to the INPUT.
Frequencies up to 15kHz can be used for modulation at RF above 3MHz. The audio
input voltage should not exceed 2V; this is to prevent modulation distortion.