Category Archives :Radio knowledge

In amateur radio world, one of ham's favorite radios is the SDR transceiver. So what's SDR radio? What is the difference between SDR and traditional transceiver ? what are advantages and disadvantage of SDR? Let's study together.  ...

The specification of walkie-talkie is an important reference for us to know whether it meets our needs. For example, the working mode of walkie-talkies is often marked with words such as F3E or F2D. Do you know what it means? Today let's study together.  ...

NVIS is short for Near Vertical Incidence Skywave. It's short-range near field communication method which is widely used in military communications, nearby emergency rescue and other fields. NVIS and DW are the main methods of shortwave communication, so what is the difference between them?  ...

Digital filter can effectively filter out the frequency point of a specific frequency or the frequency other than the frequency point and is a device or circuit that has a signal processing effect. It is equivalent to the "sieve" of frequency.  ...

The collective Stations take part in the match in 1786 and 1987  ...

China's Amateur Radio Competition Set sail again in 1985  ...

The start of amateur radio activities in our country is not too late. In the 1920s, Shanghai was already the economic and trade center of East Asia at that time. Not only commercial radio stations were introduced, but amateur radio activities were also brought into China.  ...

The history of the global amateur radio competition has been nearly 100 years, and it has almost accompanied the development history of the entire amateur radio DX communication.  ...

In recent years, amateur radios have popularly used digital modes for communication. Many ham friends have heard of the names of digital modes such as JT65 and FT8. Ham friends who have HF or 50MHz radio stations can hear many "beep-hoo-" tones at certain points in time on the frequencies in the table below. This is a kind of digital mode, FT8 signal.  ...

A link budget is usually used to estimate the longest distance for a signal to travel between transmitter and receiver. This is also the main method for evaluating the coverage range of a wireless communication system and is an important work in wireless network planning. So how to make a simple link budget?  ...