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How to measure the transmitter power output to check the COFDM wireless video transmitters’ real power amplifier inside?

To transmit wireless video signals farther, the transmitter needs a powerful power amplifier.

So how do we measure the power amplifier of a wireless transmitter? مذکورہ ویڈیو میں, we have measured three times COFDM-908T, which was ordered from our customer. This client needs a 10-watt power amplifier for ground wireless video transmission. So we measure the transmitter TX power for him.

We have to use specialized instruments to test the RF output power of wireless video amplifiers.

پہلا, we need to know a table of output power and power amplifier power. یہاں آؤٹ پٹ پاور اور آلہ کے ذریعہ دکھائے جانے والے dBm پیرامیٹرز کے درمیان کچھ خط و کتابت ہیں۔.

20mW 13dBm ہے۔
200mW 23dBm ہے۔
1 واٹس 30dBm ہے۔
2 واٹس 33dBm ہے۔
5 واٹس 37dBm ہے۔
10 واٹس 40dBm ہے۔
20 واٹس 43dBm ہے۔
50 واٹس 47dBm ہے۔
100 واٹس 50dBm ہے۔

The transmitters in the video all have built-in 10-watt power amplifiers, and the corresponding instrument should measure 40dBm.

عین اسی وقت پر, our equipment has a 40dBm attenuator added, so the instrument should show a performance of around 0dBm.

You can see the performance indicators in the video: one is 0 میں dBm, one is 0.07 میں dBm, and one is 0.18 میں dBm. From the table, we can see 0 میں dBm, They all have built-in 10-watt power amplifiers.

In the next video, we will demonstrate how to modify the output power through the parameter modification board.

We will show you how to change the wireless video transmitter from a 2-watt amplifier to a 1-watt one.

Please remember to follow our YouTube channel. If you have any suggestions for the COFDM wireless video transmitter and receiver, please feel free to communicate with us.

To measure the RF output power of a wireless video transmitter, you must use a power meter and a power sensor that are compatible with the transmitter’s signal format and modulation type.

To achieve proper power transfer, you must also match the impedance of the transmitter and the power sensor. Here are some procedures to follow:

Turn on the power meter and connect the power sensor. Check that they are correctly calibrated and configured.
Using a coaxial cable, connect the transmitter output to the power sensor input. To protect the power sensor from damage caused by high power levels, use an attenuation or a dummy load if possible.
Set the transmitter’s frequency and modulation mode as desired. As needed, adjust the output power level.
Pay attention to the power value displayed on the power meter. This is the transmitter’s RF output power in watts or decibels (میں dBm). If you have an oscilloscope, you may also use the peak-to-peak voltage formula to compute power.
A directional coupler or a reflectometer is required to monitor the voltage standing wave ratio (VSWR), which indicates how well the transmitter and the power sensor are matched.
These devices can calculate the VSWR by measuring both forward and reflected power. A low VSWR indicates a good impedance match and low power loss.