How to Measure Adjacent Channel Power with a Spectrum Analyzer?

Adjacent channel power, as the name suggests, measures the power of the left and right channels (also known as upper and lower channels) adjacent to the transmitter's working channel. The smaller the power leakage of the carrier channel measured in the adjacent channel, the better the performance. Excessive energy leakage into adjacent channels will cause interference to adjacent operating systems and affect the normal communication of adjacent channels, so adjacent channel power is an important index to evaluate the performance of transmitters.

The adjacent channel power function of the spectrum analyzer is used to measure and analyze the power characteristics of the signal in a specified frequency range. The measurement of adjacent channel power can help us quickly locate the maximum and minimum value of signal strength, to carry out leakage detection, interference analysis, communication debugging, and other work. When we need to know the power distribution characteristics of the signal in a certain frequency range, we can use the adjacent channel power function to measure.

Below is the introduction to how to use spectrum analyzer SA9232 and RF signal generator TFG3836 to measure adjacent channel power.

Set the central frequency of the spectrum analyzer according to the generator output frequency.

To enter the adjacent channel power function, you need to press【MEAS】,select【ACP】

Set the adjacent channel frequency offset and bandwidth according to the requirements, up to 6 adjacent channels.

 

Fig 1. ACP Measurement

Stopwatch And Timer Calibration

Stopwatch and timer calibrations are perhaps the most common calibrations performed in the field of time and frequency metrology. Hundreds of laboratories and metrology institutes calibrate many thousands of timing devices annually to meet legal and organizational metrology requirements.

There are three generally accepted methods for calibrating a stopwatch or timer: the direct comparison method, the totalize method, and the time base method. The first two methods consist of time interval measurements that compare the time interval display of the DUT to a traceable time interval reference. In the case of the direct comparison method, the time interval reference is normally a signal broadcast, usually in the form of audio tones. In the case of the totalize method, the time interval reference is generated in the laboratory using a synthesized signal generator, a universal counter, and a traceable frequency standard. The third method, the time-based method, is a frequency measurement. It compares the frequency of the DUT's time-base oscillator to a traceable frequency standard.

Suin SF2002 stopwatch calibrator is an easy-operating and high-precision instrument that adapts the totalize method, which can calibrate electric stopwatches (405,407,408,415/417), mechanical stopwatches and digital quartz electronic stopwatches.

It can not only calibrate one stopwatch but also several ones with several fixtures, which meet different requirements, just like below pictures shown.

 

 

 

If you want to know more information about it, please contact us for its User's manual or operation video.

Basic Function Introduction - Frequency Measurement

Frequency measurement plays a very important role in the field of electronic engineering. Whether in communication systems, power systems or other fields, accurate measurement of the frequency of signals is essential. In communication systems, frequency measurements are used to ensure that the signals being sent and received are in the correct frequency range. For example, during modulation and demodulation, the frequency of a signal needs to be measured accurately to ensure that the information is transmitted correctly. In power systems, frequency measurements are critical to maintaining the stability of the power grid, where variations in frequency can lead to faults or instability in the power system.

The frequency range can be divided into three parts: low frequency: below 200Hz, medium frequency: 200Hz-6khz, and high frequency: above 6KHz. In the market, the most commonly used equipment for measuring frequency are oscilloscopes, spectrum analyzers, and frequency counters, of which oscilloscopes are relatively low in frequency measurement accuracy and have large errors. The spectrum analyzer can accurately measure the frequency and display the spectrum, but measurement speed is slow and cannot quickly track and capture the change of the measured signal frequency in real-time. The frequency meter can quickly and accurately capture the change in the frequency of the measured signal, and it has a wider range of applications.

Now, we take the Suin SS7300 frequency counter as an example to introduce its frequency measurement function:

SS7300 has three output channels, with 1 and 2 channels measuring up to 200MHz.

Set the frequency of the signal generator to 200MHz, select the frequency measurement function, and the measurement results are shown in Fig 1:

 

Fig 1. Frequency Measurement

 

Channel 3 can be equipped with channel options in a higher frequency range to meet customer needs, as shown in Fig 2, and can reach up to 40GHz.

 

Fig 2. Channel Options

If you have frequency measurement needs, welcome to consult.

What is an AC signal generator?

 AC signal generator

TFG1900A Series are economical function generator which has two channel outputs, 20ppm frequency accuracy, and can make 16 kinds waveform. Besides that, with multifunction, simple keyboard and digital displaying, it is broadly used in education, personal test and industrial field to meet your basic test requirement.

Features

* Dual channel outputs

* Frequency accuracy 20ppm and 1μHz resolution

* Abundant modulation function AM, FM, PM,

  PWM and FSK

* Provide sweep and burst

* 100MHz Built-in counter

* Standard interface: USB Host & Device

Specifications

		TFG1905A	TFG1910A	TFG1920A
Frequency
Range	Sine	1μHz ~ 5MHz	1μHz ~ 10MHz	1μHz ~ 20MHz
	Square, Pulse	1μHz ~ 5MHz
	Others	1μHz ~ 1MHz
Resolution		1μHz, 6 digits
Accuracy		±20ppm
Waveform
Type		11 build-in waveform(Sine, Square, Ramp, Pulse, etc.) +5 user-defined arbitrary waveforms
Length		4096 points
Sampling Rate		100 MSa/s
Vertical Resolution		10 bits
Amplitude
Range	Frequency≤8MHz	0 ~ 10Vpp(50Ω),  0 ~ 20Vpp(Open circuit)
	Frequency>8MHz	0 ~ 9  Vpp(50Ω),  0 ~ 18Vpp(Open circuit)
Resolution		2mVpp(Amplitude>2Vpp)
		0.2mVpp(Amplitude≤2Vpp)
Offset (Ampl. 0Vpp)
Range		±5Vdc (50Ω), ±10Vdc (Open circuit)
Resolution		2mVdc
Modulation (CHA)
FM,AM,PM,PWM	Carrier Waveform	16 waveforms, Sine, Square, Ramp, etc. (only Pulse for PWM)
	Modulating Waveform	16 waveforms, Sine, Square, Ramp, etc.
	Modulating Frequency	2mHz ~ 20kHz
FSK	Carrier Waveform	16 waveforms, Sine, Square, Ramp, etc.
	Hope Frequency	1μHz ~ 5MHz	1μHz ~ 10MHz	1μHz ~ 20MHz
	Rate	1mHz ~ 100kHz
Sweep (CHA)
Carrier   Waveform		16 waveforms, Sine, Square, Ramp, etc.
Type		Linear or Logarithmic
Sweep Time		50ms ~ 500s
Burst (CHA)
Carrier  Waveform		16 waveforms, Sine, Square, Ramp, etc.
Burst Count		1 ~ 1000000
Internal Period		1μs ~ 500s
Start/Stop Phase		0° ~ 360°
SYNC Output
Waveform Characteristic		Square, rise/fall time ≤ 20ns
Output Level		TTL compatible
Counter
Frequency Range		1Hz ~ 100MHz
Input Amplitude		100mVrms ~ 7Vrms
Period		50ms ~ 5s
General   Characteristics
Power		AC 100 ~ 240V, 45 ~ 65Hz, < 30VA
Display		VFD display
Dimension & Weight		322×256×102mm, Approx.1.5 kg

Serial and Parallel Connection of DC Power Supply

In the electricity experiment, sometimes we need more current or voltage power supply, in this condition, several power supplies can be parallel or serial connected to realize this function. It can be applied in many conditions, such as high power load is required in the electricity circuit, and redundant power supplies are required to strengthen the system's stability. The parallel or serial connection of power supplies can increase the current or voltage output in the electricity circuit.

Along with the technology development, smaller size, and multichannel power supply can meet nowadays engineers and teaching requirements. Suin SK3323/3325/3503 three channels programmable DC power supply is just one example.

Please see the below pictures of the parallel and serial connection of SK3323 and pay attention to some points during the experiment.

1. Connection way. Parallel and serial connection are two normal connection ways.

During serial, the positive terminal of channel 1 should be connected to the negative terminal of channel 2, the current of the serial connection is the same as that in independent channel output, while the voltage is the sum of two channels, which solves the high voltage requirement.

 

Serial connection on SK3323

 

In parallel, you just need to connect as the independent channel output, and press 【PARA】 to enter the parallel connection way. The voltage in parallel remains the same as that in independent channel output, but the current is the sum of two channels, which solves the high current requirement.

 

Parallel connection on SK3323

 

2. Over voltage and over current protection. Parallel or serial connection power supply should have proper control and protection to the current and voltage to make sure the power supply running normally without making any injury to the operator or the instruments. Suin SK3323/3325/3503 power supply has such a function too.

 

If you are interested in it or have any questions, please do not hesitate to contact Suin.

Difference between Logger and Monitor of SA2200

With the increasing power quality problem, more and more people pay attention to power quality. To know more about the power quality, it is necessary to measure, collect, and analyze the data of the power grid.

A logger can record basic parameters such as current, voltage, and power factor, and can also record various abnormal events of power quality, such as voltage fluctuations, harmonics, unbalance, and so on.

Monitor is the real-time measurement and data collection of various power quality indicators to ensure the observation, recording, and dynamic analysis of the power system, and the comprehensive evaluation of power quality indicators to optimize the monitoring system of the whole system. According to the specific characteristics of various indicators, the power quality problem is detected by layers, and a variety of disturbance information is identified, extracted, and analyzed, which provides a credible basis for the development of specific measures to improve power quality and control grid pollution.

The difference between the two is that the Logger records more parameters, and the recording interval can be set but the recording time is shorter, while the power quality monitoring is to monitor specific parameters and the recording time is longer.

Take our Class A power quality analyzer SA2200 as an example:

the recorder function, the shortest time interval can be set to 1s, the duration can also be set to 2 hours, and you can choose the parameters of the record, shown in Fig 2.

 

Fig 1. Logger

 

Fig 2. Parameters of Logger

The measurement parameters of the Monitor are default, the shortest measurement time is 2 hours, and the measurement interval cannot be set, as shown in Fig 3.

 

Fig 3. Monitor

If you want to know more details about these two functions, welcome to inquire.

Introduction of Suin SS7406 Frequency Counter/Timer/Analyzer

Frequency counters are test instruments used in many applications including laboratories, education, and industrial field to measure the frequency and time of signals very accurately. Nowadays high speed and more accurate frequency counters are required by engineers, Suin SS7406 Universal Frequency Counter/Timer/Analyzer comes out in this condition.

Pict 1: SS7406 Front View

 

Main Features:

SS7406 can measure frequency, period, time interval, pulse width, duty cycle, phase difference. Frequency can be tested from 1mHz to 200MHz in two channels. Additionally, several higher frequency options max to 40GHz can be selected in channel 3. 11 digits per second frequency resolution makes it suitable for measurement from short-term phase locked loop jitter to the long-term drift of atomic clocks. 25ps single shot time resolution makes it one of the highest resolution counters in the market.

 

Besides that, SS7406 also can measure frequency ratio, limit, and statistics calculation. This complete measuring function makes it more popular in the market.

 

The standard time base’s nominal frequency is 10MHz. The test can be controlled not only by the internal gate automatically, but also by the external signal triggering. For more stable measurement, there is a high stability crystal oscillator as an optional selection.

 

Advantages:

Unlike conventional counters that only have numeric displays, SS7406 provides live, graphical displays of measurement results. Graphical data is available in two formats: histogram and trendgram. You can select any by your real requirement.

 

Pict 2: Histogram

 

 

Pict 3: Trendgram

 

Meantime, it is designed as 2U instrument case, which can be used not only as a sole benchtop instrument but also in a 19'' equipment cabinet.