PL-360 ETM function introduction:
ETM: Easy Tuning Mode
ETM tuning method————Using the radio receiving circuit and MCU control software, pre-exclude the frequency points that do not have radio programs, and select the frequency points that are suspected to be radio stations, making it easy for users in the future Find out which radio station you want to listen to.
As we all know, the frequency range of civil radio broadcasting and the frequency interval of broadcasting stations are usually:
Frequency modulation: frequency range 87 — 108 MHz frequency interval 0.1 MHz
Medium wave: frequency range 522 — 1620 kHz frequency interval 9 kHz
Shortwave: frequency range 1700 — 30000 kHz frequency interval 5 kHz
Theoretically, the number of frequencies allowed for radio stations in each band is:
FM 87 — 108 MHz The radio frequency points that can be accommodated are(108-87)÷0.1 = 210
Medium wave 522 — 1620 kHz can accommodate the radio frequency point is(1620-522)÷9 = 122
Shortwave 1700 — 30000 kHz can accommodate the radio frequency point is(30000-1700)÷5 = 5660
【The frequency of PL-360''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s shortwave reception is(21950 —2300)÷5 = 3930】
Digital tuning radios are designed to receive range and frequency step interval in accordance with the above regulations. Searching for radio stations with digital tuning radio, from low to end, FM has to search 210 frequency points, medium wave has to search 122 frequency points, and short wave has to search thousands of frequency points.
But in fact, for many reasons, such as the prevention of adjacent frequency interference, not every frequency has a radio broadcast. For example, if you listen to FM radio in different places, you will receive at least a few radio stations, and at most you will receive 60 — 70 radio broadcasts. For example, due to signal transmission in medium wave, the distribution of the number of radio stations is characterized by less during the day and more at night, and only a few — dozens of radio stations can be received.
Take PL-360''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''s shortwave reception as an example:
Short-wave band has(21950-2300)÷5 = 3930 frequency points, and the actual radio programs that can be listened to are dozens of during the day and hundreds of in the evening, and the frequency distribution of radio stations in the morning, midnight and evening is almost different. Assuming that the radio can receive only 200 radio programs, then in order to search these 200 radio stations, you have to search for nearly 4000 frequency points, so it takes a long time to search.
In response to the above-mentioned problems, Tecsun has developed an ETM tuning method, which uses the receiver circuit of the radio and MCU control software to preclude the frequency points without radio programs and select the frequency points of the suspected radio(Such as programs in different places and languages, as well as interference signals from the local electromagnetic environment). That is to say, with the ETM tuning method, dozens of ——several hundred suspected frequencies can be selected from thousands of frequency points, and the user can easily select them from these in the subsequent closing operations. Among the suspected frequencies, find out the radio station program you want to listen to.
To listen to the radio with the ETM convenient tuning method, the frequency points that users need to search can be reduced to:
FM several — dozens, day and night are basically the same
Medium wave several — dozens less during the day and more at night
Shortwave dozens — hundreds of frequency points Fewer days during the day, less late at night, and more in the evening, and in different time periods, radio stations are distributed in different frequency ranges.
Operation method of ETM function:
To use the ETM function, you must first press and hold the ETM button to search for the full frequency of the band you are in, and select the frequency of the suspected radio station. After the optimization, you can use the tuning knob to operate the tuning.
Special reminder: The number and frequency distribution of suspected radio stations are different at different times, different locations, and different bands, especially in the short band.
Use the ETM method to listen to the radio in the same place:
FM band: Just do the ETM optimization once during the day, and don''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''t do the ETM optimization frequency every time in the future. However, if you change the listening location, it is recommended to do ETM again.
Medium wave band: You can do an ETM selection at night when there are more radio stations. But if you change the listening location, it is recommended to do ETM again.
Shortwave band: The ETM method is convenient and practical to listen to shortwave broadcasting. To listen to shortwave broadcasts in ETM mode at different times, it is recommended to select ETM first.
In order to avoid searching for too many clutter interference signals, it is recommended that you go to the balcony or outdoor open area for ETM selection.
With the ETM tuning method, you will feel that listening to the radio can be so easy and so fast.
Q&A:
Q: What is the difference between ETM and ATS?
A: ETM and ATS are basically the same in the principle of search/storage frequency.
The signal strength threshold of the radio station during ATS search is set to be relatively high, in order to minimize the locking of non-radio frequencies, and radio frequencies that are too weak and worthless to listen to. The searched frequency memory is automatically stored in the editable memory, and you can delete and increase the radio frequency at will afterwards. After sorting the stored radio frequencies, you can easily call out the radio frequencies you want to listen to from the memory. Because of this, I believe you will not be willing to perform ATS operations at will and overwrite the radio frequencies that you have worked so hard to edit and organize.
ETM is a convenient tuning method based on frequency tuning. It has a lower threshold for search and lock. It aims to exclude frequencies that are definitely not radio or even noise. This mode can lock on weaker suspected radio signals and finish ETM Listen to the radio after selecting the frequency, which can save your operating time and increase the life of the tuning knob. Because the convenient ETM tuning method does not provide editing functions, you can perform ETM operations at any time and search for suspected radio frequencies again. .
One tip: In a better listening environment, the number of radio frequencies searched by ETM and ATS may be the same, especially on the FM band. Anyway, you won’t lose anything with ETM. PL-360 has both ATS and ETM functions. You can compare it.