Telecom and Networking

Faked telephone ring tone

The Western Electric Model 500 and its subsequent variants were so ubiquitous that you almost couldn’t go anywhere without seeing one, especially in the United States. You have seen and heard this literal fixture of American life phone on countless of TV series and movies. Unfortunately many producers have been a little lazy and did

Ethernet over voltage protector

I got 10BASE-T and 100BASE-TX Ethernet running through this over voltage protector. They are nor designed for faster data rate. Those protectors are designed to protect two 100 ohms wire pairs. They are designed to work well up to 60 MHz signal and have low capacitance (around 30 pF between wire pair wires). Links to

Telephone connector adapters

Here is a collectio of adapters for different phone line connectors around the world. Those telephone connector adapters are designed to connect RJ11/12 plug cable to wall phone outlet on different countries. Different countries use or used to use different type telephone connectors on wall outlets. Those adapters were are used convert one country specific

Telephone cables start to dissappear

Old telephone cables are being pulled from the ground to make room for new fiber optic cables in Helsinki Finland. Bye bye PSTN. According to plans they will be gone in few years. Here they are pulling out the old telephone cable. Freshly pulled out “filled liquorice”. Old telephone wires to carry PSTN, ADSL and

Video balun circuits

Traditionally analogue video transmission is done using 75 ohm coaxial cables. Those video signals are not directly compatible with nowadays more widely used twisted pair wiring (CAT5, CAT6 etc..), which means you just can’t wire the signals directly form video output to a twisted pair wire. The main problems in connecting 75 ohms video source

WiFi location

In three years or so, the Wi-Fi specification is scheduled to get an upgrade that will turn wireless devices into sensors capable of gathering data about the people and objects bathed in their signals. In this WiFi is following the footsteps of Bluetooth that got location features already some years ago. “When 802.11bf will be

Ethernet over XLR wiring

I have written about running audio signals over CAT 5/6/7 wires normally designed to carry Ethernet traffic. But is is possible to run Ethernet over audio cabling terminated with XLR connectors? Gearspace discussion at topic “Ethernet over XLR – Can I do this ???” had following question: We recently moved into an old recording studio