Lesson plan
WT-4
adapter (B) . WT-4 (adopted as ВТ-4 in the USSR ) is a Polish telephone plug used to connect telephone sets to the network. Introduced in the second half of the 20th century and adopted in several Eastern Bloc countries as a standard . It has since been replaced by the RJ-11 standard. Sockets are labelled with the text GTN-4 (РТШ-4 in the USSR ). WT-4 plugs consist of 4 metal pins with an additional plastic pin at the bottom to prevent inserting the plug the wrong way round. When the plug is inserted into a socket, the plastic pin also disconnects a 1μF capacitor built into the socket. When connected, the capacitor simulates a telephone set with the handset hung up. This allows for the testing of the line even when the subscriber doesn't have a telephone connected to the network. In the mid-1990s, installations of WT-4 plugs began to be phased out, and the standardized shape of the socket was used to install RJ-11 connectors instead. A rare 6-pin version also existed, called WT-6. Extra pins (numbered with the missing 1 and 2) were located between the existing pins 3 and 5, and 4 and 6, respectively. These extra pins were used for powering telephone sets with illuminated rotary dials, as well as some more advanced telephone installations.
Article summary
adapter (B) . WT-4 (adopted as ВТ-4 in the USSR ) is a Polish telephone plug used to connect telephone sets to the network. Introduced in the second half of the 20th century and adopted in several Eastern Bloc countries as a standard . It has since been replaced by the RJ-11 standard. Sockets are labelled with the text GTN-4 (РТШ-4 in the USSR ). WT-4 plugs consist of 4 metal pins with an additional plastic pin at the bottom to prevent inserting the plug the wrong way round. When the plug is inserted into a socket, the plastic pin also disconnects a 1μF capacitor built into the socket. When connected, the capacitor simulates a telephone set with the handset hung up. This allows for the testing of the line even when the subscriber doesn't have a telephone connected to the network. In the mid-1990s, installations of WT-4 plugs began to be phased out, and the standardized shape of the socket was used to install RJ-11 connectors instead. A rare 6-pin version also existed, called WT-6. Extra pins (numbered with the missing 1 and 2) were located between the existing pins 3 and 5, and 4 and 6, respectively. These extra pins were used for powering telephone sets with illuminated rotary dials, as well as some more advanced telephone installations.
Key claims
No claims recorded.
Discussion questions
- Summarise the article in your own words. Which single claim would you verify first, and why?
- Which claim in this article is most likely to be revised as the sources update? How would you check its current status?
- If two sources disagreed about one of these facts, what would you need in order to trust one over the other?
Bibliography
No sources recorded.
Key claims and bibliography are generated from the same tracked claims and sources as the article page.