Homemade ADSL splitter [with schematic diagram]

Since installing ADSL , making phone calls while surfing the Internet has become a problem. When other rooms answer the phone, the Internet is disconnected. What's even worse is that there is a strange sound of chickens on the phone. The method of installing a splitter on the incoming line is not feasible. The house that costs tens of thousands of dollars to renovate has another line for ADSL, which is far away from the machine. Should I wire it in the wall or drill a hole in the wall? There is no choice but to buy two or three splitters. When I went to the telecommunications bureau and asked, they wanted 50 yuan each! It's robbery. I didn't buy one, but when I asked at Zhujiang Road, it was also 50 yuan. They are all profiteers. I went home and thought, why not do it myself?

You should know that telephones use frequencies below 4KHz, while ADSL uses the high frequency band of 4k-1.5MHz. All you need to do is block the high frequency band of ADSL. Blocking high frequencies is what inductors are good at. According to the inductance formula, you can quickly calculate that 20-50 millihenries can meet the requirements.

The next day I bought a 33 millihenry inductor for 20 cents and connected it in series to my phone line. It worked very well. The noise was gone. The way to connect in series is to open the phone case and connect one in series to the incoming solder point of the circuit board. You can also buy a 2-way phone socket and solder one in series in the middle. I currently solder one in series to each phone, and it works very well.

It should be noted that 33 millihenries is the best for general telephone calls. For caller ID to work, 10 or 20 millihenries of inductance are required, but some noise will not be filtered out.

Those who are worried about being disconnected while on the phone need not be afraid. You should know that connecting an inductor to the phone is equivalent to isolating high frequency from low frequency. It can prevent the high frequency signal of ADSL from interfering with the phone, and also prevent the high frequency signal of ADSL from interfering with the phone. As long as the inductor is large enough, there will be no impact on the Internet when making a phone call. This has been proven in actual use, and the download speed does not fluctuate when making a phone call.

I strongly recommend that friends who install ADSL solder the splitter by themselves. The splitter sold by telecom is the same, just with an extra shell!

The schematic diagram of the commercially available ADSL splitter is as follows. Interested friends can refer to it.