Archive for the ‘telephony’ Category
We talk a lot about the band conditions due to the Sunspot cycle. Most of it on Facebook and other places is about how “dead” the bands are at this point. We all can’t wait until the cycle starts to rise and we will be making contacts with little effort. I remember in my conversation with Chuck Adams, K7QO in Episode 58, that he really enjoys operating is “Pigrig”, one watt, CW transceiver on 20 meters. When I asked him, (I liberally paraphrase) “but Chuck, the bands are dead. How does that work for you?”. His reply was that while most hams are listening to the bands, he calls CQ until he gets a reply. Works every time.
My QSO this week is with Tomas Hood, NW7US, who has years of expertise in propagation and Solar activity. He is the propagation editor of more than a few radio magazines and websites. In our post-recording conversation we discussed this phenomenon of listening and not calling CQ. I even had this idea that maybe one of the reasons that the digital modes are so successful is because they “beacon”, as part of the whole digital experience, the same as calling CQ. This is why they make contacts. From what I see, looking at PSK Reporter, hams are making lots of contacts worldwide using the digital modes. While SSB may not be working so well, CW and the digital modes seem to work fine.
I like to work on my bench or make the podcast while listening to the bands. Jeff Damm, WA7MLH, in Episode 177, says that he will put his keyer in CQ mode while he is working on a new radio. Invariably, sometimes after many minutes, he gets a reply. Great idea Jeff!
Episode 184 can be found here: https://www.qsotoday.com/podcasts/nw7us
Highlights of Episode 184:
Tomas Hood, NW7US is the propagation editor of a number of shortwave and amateur radio magazines, and has a wide variety of websites, that grew out of his love for all things radio, and for listening on the bands to far off DX and commercial broadcast stations. Tomas shares his understanding of propagation and the lessons we can learn from listening, really listening to the QSOs and exchanges during contest operation.
All of the QSO Today episodes are great. I enjoy hearing about many different hams. Do check out all of the episodes that Eric has published.
73 de NW7US dit dit
This is for you vintage science film buffs: here is a circa 1920 film: How the Telephone Talks (A Silent Film).
This is an educational film from 1920 that explained the “modern” telephone. The concepts are still relevant to today’s modern versions, including the cell phone, which is both radio and telephone.
A telephone, or phone, is a telecommunications device that permits two or more users to conduct a conversation when they are not in the same vicinity of each other to be heard directly. A telephone converts sound, typically and most efficiently the human voice, into electronic signals suitable for transmission via cables or other transmission media over long distances, and replays such signals simultaneously in audible form to its user. The word telephone has been adapted into the vocabulary of many languages. It is derived from the Greek: τῆλε, tēle, far and φωνή, phōnē, voice, together meaning distant voice.
First patented in 1876 by Alexander Graham Bell and further developed by many others, the telephone was the first device in history that enabled people to talk directly with each other across large distances. Telephones became rapidly indispensable to businesses, government, and households, and are today some of the most widely used small appliances.
The essential elements of a telephone are a microphone (transmitter) to speak into and an earphone (receiver) which reproduces the voice of the distant person. In addition, most telephones contain a ringer which produces a sound to announce an incoming telephone call, and a dial used to enter a telephone number when initiating a call to another telephone. Until approximately the 1970s most telephones used a rotary dial, which was superseded by the modern Touch-Tone push-button dial, first introduced by AT&T in 1963. The receiver and transmitter are usually built into a handset which is held up to the ear and mouth during conversation. The dial may be located either on the handset, or on a base unit to which the handset is connected by a cord containing wires. The transmitter converts the sound waves to electrical signals which are sent through the telephone network to the receiving phone. The receiving telephone converts the signals into audible sound in the receiver, or sometimes a loudspeaker. Telephones are a duplex communications medium, meaning they allow the people on both ends to talk simultaneously.
A landline telephone is connected by a pair of wires to the telephone network, while a mobile phone, such as a cellular phone, is portable and communicates with the telephone network by radio transmissions. A cordless telephone has a portable handset which communicates by radio transmission with the handset base station which is connected by wire to the telephone network.
The telephone network, consisting of a worldwide net of telephone lines, fiber optic cables, microwave transmission, cellular networks, communications satellites, and undersea telephone cables connected by switching centers, allows any telephone in the world to communicate with any other. Each telephone line has an identifying number called its telephone number. To initiate a telephone call the user enters the other telephone’s number into a numeric keypad on the phone.
Although originally designed for simple voice communications, most modern telephones have many additional capabilities. They may be able to record spoken messages, send and receive text messages, take and display photographs or video, play music, and surf the Internet. A current trend is phones that integrate all mobile communication and computing needs; these are called smartphones.