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ポータブル発電機 Com-Power CGO-501のPDF 取扱説明書をオンラインで閲覧またはダウンロードできます。Com-Power CGO-501 14 ページ。 Comb generators

CGO-501, CGO-505 and CGO-515 Comb Generators

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Compare these levels with subsequent measurements to make sure that the pattern does not have abrupt change

from the established daily log at any frequency.

This log is used to detect any test equipment or test site related problems, as described below.

Problems Related to Test Equipment

Variation on the log of the Comb Generator output data is dependent on the test equipment as well as site. The

Comb Generator replaces the EUT. The Comb Generator not only generates the output simultaneously at all the

harmonics, but it minimizes any variation of its output. This is achieved by utilizing a stabilized signal circuit as well

as geometry of the radiator. The circuit stability is maximized by design, whereas the geometry of the radiated

source is optimized by eliminating all cables during the Radiated Emission Mode. The typical variation of Comb

Generator output at any frequency is less than ± 1 dB.

With the variations due to the EUT practically eliminated, only variations remaining are due to other factors,

mainly the test instrumentation and the site. The variation due to test instrumentation is limited to the sum total

of the tolerance on all test equipment used (spectrum analyzer, antenna, preamplifier, cables). A few days of data

will establish the range of variation to be expected at a site. This is generally less than ± 3 dB. Any variation in the

readings above normal variation indicates a potential problem.

After the daily log is established for a few days, any problem is easily detected as a larger variation. This procedure

allows immediate detection of a major problem with the test equipment.

Problems Related to site

The above procedure cannot distinguish between problems related to the test site. The Comb Generator can be

used in two ways to detect any problem with a test site. One method is to start the daily log immediately after the

test site is calibrated. This way, one is certain about the validity of the data taken on the test site. The second

method is to calibrate the Comb Generator radiated output as absolute emission level. Such calibration is

provided as an option with the Comb Generators.

In addition, when difficulty arises with any EUT data taken at two different sites, the Comb Generator can be used

to determine if both sites give reliable results, just by comparing the data at the two sites with the Comb

Generator. In this case, if the two sites do not produce comparable results, a Comb Generator with calibrated data

is certainly required to determine the faulty site.

Problems Related to Test Personnel

The Comb Generator cannot directly help to eliminate the test personnel related problems. However, by

increasing the confidence level and establishing definite procedures for eliminating site and equipment related

problems it helps tremendously to reduce the problems related to EMI measurements.

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Rev. 021020