BRUEL & KJAER 2006 - Page 9

can be made as described under "Operation", p. 14. To allow the reference
voltage to be independent of whether the oscillator is loaded by 50 [} or by
the high impedance of the Input Probe, the output impedance at the REF.
VOLT AGE terminal is less than 1 .Q. The reference voltage will change by less
than 2% for a 0- 50°C temperature variation.
An overall accuracy of the RF-meter of ± o.5 dB is to be expected in ranges
1, 2, 3, and 4. Better than ± 1 dB in ranges 5 and 6 and better than ± 1.5 dB
in range 7. At the higher frequencies the attenuator must be employed if
capacitive loading is not acceptable.
However, this accuracy is achieved only for voltages well above the level of
dB
~ -~---4--4---4---+4-~~~+--+-~-~~+-~~--+-~
100
200 500 1000 2000 50 000 100 000 200 000 500 000
Frequency (kHz)
Fig. 1.5. Sensitivity of the Heterodyne Voltmeter Type 2006.
dB/1J
I
\2o
Bandwidth
Position '"Wide''
\
should not be .1.
I
used below 6 MHz
+15
+10 \..
I
Probe ''jide'"
I
Probe '"Narrow'"
+ 5
!
I
- 5
100 200 500 1 000 2 000
5 000 10 000 20 000 50 000 100 000 200 000 500 000
Frequency/ kHz
469 002
Fig. 1.6. Inherent Noise of the Heterodyne Voltmeter Type 2006 (50 ftV range)
7