Instructions

Table Of Contents
Frequency Counter (R&S RTH-K33)
R&S
®
Scope Rider RTH
258User Manual 1326.1578.02 ─ 15
11 Frequency Counter (R&S RTH-K33)
The frequency counter is only available if the counter mode option R&S RTH-K33 is
installed.
The R&S RTH measures frequencies in various ways:
You can use the automatic measurement function in scope mode.
The FFT analysis mode converts the data into the frequency domain, providing a
spectrum of the input signal (see Chapter 6.1, "FFT Mode", on page 109). During
FFT analysis, the frequency resolution is restricted by the selected data acquisition
settings (channel bandwidth, frequency span, and time scale).
To determine the frequency of an input signal accurately without changing the data
acquisition settings, the R&S RTH is equipped with a signal counter function. The
signal counter counts the zero crossings of the input signal (thus the term signal
counter) and derives the precise frequency value.
The R&S RTH counter mode option provides two separate counters. One counter can
be used as a reference for the second one, so that the deviation from the reference
value can be compensated for and the frequency becomes more accurate. Alterna-
tively, both counters can measure different input signals.
Using the data logger, you can also store a series of frequency values measured by
the counter over time.
11.1 Accessing the Counter Mode
1. Press the [MODE] key.
2. Select "Counter".
Accessing the Counter Mode