Single Source Regulated Power Supply; Electronic Frequency Control (Efc); 10 Mhz Frequency Output Signal; Figure 2-1. Single Source Regulated Power Supply - HP 10811A Operating & Service Manual

2-10. Single Source Regulated Power Supply

2-11. A single source of +20 to +30V dc with 10% regulation may be used to power both the oven and
oscillator amplifier circuits if a simple IC regulator is used. A suggested circuit is shown in Figure
2-1. The resistor and capacitor connected to terminals 3 and 4 of the IC minimize ripple and noise
in the regulated output.

2-12. ELECTRONIC FREQUENCY CONTROL (EFC)

2-13. The EFC allows the oscillator to be tuned over a 1 Hz range (1 x 10-7) by applying -5 to +5 volts
to the EFC input. As the EFC voltage goes positive the output frequency will go lower. Conversely,
as the EFC voltage goes negative, the output frequency will go higher.
2-14. Since noise on the EFC line affects the oscillator's stability (noise appears as FM on the output),
care must be taken to ensure that a relatively noise free EFC voltage source is used. The noise
level must be kept below 100 µV to maintain good stability performance.
2-15. The EFC input should be connected to oscillator circuit ground if not used. A shorting plug (1250-
0911) is supplied with 10811B for this purpose. The EFC input on the 10811A should be
grounded at the printed circuit connector by wiring pins 5 and 6 together.

2-16. 10 MHz FREQUENCY OUTPUT SIGNAL

2-17. The 10 MHz output is ac coupled from a source impedance of approximately 50 ohms. The signal
level is .55 ±.05 into a 50 ohms load or 1-volt ±20% into a 1 K ohm load.

Figure 2-1. Single Source Regulated Power Supply

Model 10811A/B
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