Teledevice Radio

[Ane Neemann]

Mobileradio telephone systems were mobile telephony systems that preceded modern cellular network technology. Since they were the predecessors of the first generation of cellular telephones, these systems are sometimes retroactively referred to as pre-cellular (or sometimes zero generation, that is, 0G) systems. Technologies used in pre-cellular systems included the Push-to-talk (PTT or manual), Mobile Telephone Service (MTS), Improved Mobile Telephone Service (IMTS), and Advanced Mobile Telephone System (AMTS) systems. These early mobile telephone systems can be distinguished from earlier closed radiotelephone systems in that they were available as a commercial service that was part of the public switched telephone network, with their own telephone numbers, rather than part of a closed network such as a police radio or taxi dispatching system.

These mobile telephones were usually mounted in cars or trucks (thus called car phones), although portable briefcase models were also made. Typically, the transceiver (transmitter-receiver) was mounted in the vehicle trunk and attached to the "head" (dial, display, and handset) mounted near the driver seat. They were sold through WCCs (Wireline Common Carriers, a.k.a. telephone companies), RCCs (Radio Common Carriers), and two-way radio dealers.

Parallel to Improved Mobile Telephone Service (IMTS) in the US until the rollout of cellular AMPS systems, a competing mobile telephone technology was called Radio Common Carrier (RCC). The service was provided from the 1960s until the 1980s when cellular AMPS systems made RCC equipment obsolete. These systems operated in a regulated environment in competition with the Bell System's MTS and IMTS. RCCs handled telephone calls and were operated by private companies and individuals. Some systems were designed to allow customers of adjacent RCCs to use their facilities, but the universe of RCCs did not comply with any single interoperable technical standard (a capability known in modern systems as roaming). For example, the phone of an Omaha, Nebraska-based RCC service would not be likely to work in Phoenix, Arizona. At the end of RCC's existence, industry associations were working on a technical standard that would potentially have allowed roaming, and some mobile users had multiple decoders to enable operation with more than one of the common signaling formats (600/1500, 2805, and Reach). Manual operation was often a fallback for RCC roamers.

Roaming was not encouraged, in part because there was no centralized industry billing database for RCCs. Signaling formats were not standardized. For example, some systems used two-tone sequential paging to alert a mobile or handheld that a wired phone was trying to call them. Other systems used DTMF. Some used a system called Secode 2805 which transmitted an interrupted 2805 Hz tone (in a manner similar to IMTS signaling) to alert mobiles of an offered call. Some radio equipment used with RCC systems was half-duplex, push-to-talk equipment such as Motorola hand-helds or RCA 700-series conventional two-way radios. Other vehicular equipment had telephone handsets, rotary or push-button dialing, and operated full duplex like a conventional wired telephone. A few users had full-duplex briefcase telephones (which were radically advanced for their day).

Interference occurs when unwanted radio frequency signals disrupt the use of your television, radio or cordless telephone. Interference may prevent reception altogether, may cause only a temporary loss of a signal, or may affect the quality of the sound or picture produced by your equipment. The two most common causes of interference are transmitters and electrical equipment.

If your equipment is reacting to nearby transmitters such as an amateur radio or CB installation, you will have interference only when the radio operator is talking and you might be able to hear only half of the conversation. If this is the case, you may be able to verify the interference source if you see an antenna mounted on a nearby house or car.

Cordless telephones use radio frequencies and have no protection from interference. If you are experiencing interference on your cordless phone, you should contact the equipment manufacturer for assistance.

In the presence of electrical interference, you may experience frozen images or intermittent audio while viewing over-the-air television programs. This interference may be caused by equipment in your home, such as hair dryers, sewing machines, electric drills, doorbell transformers, light switches, smartphone chargers, power supplies, computing devices, washing machines, clothes dryers, fluorescent lights, LED lights, or garage door openers.

A simple method of determining the location of electrical interference is by using a portable battery-powered AM radio tuned to a quiet frequency at the lower end of the dial. You should hear static or a buzzing sound as you get close to the source of the interference. The closer you get, the more intense the static will be.

If you cannot determine the source of the electrical interference, contact the customer service department of your local power company. Most power companies will investigate the problem and take steps to correct it.

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The straight, 200 mm long radio/telephone pliers from the PRO Series is ideal for fine work and the cutting of wires. Of course Made in Germany, from the matte chromeplated steel to the two-component grip, which unites exceptional tactile qualities and ergonomics.

I have searched image banks and Googled period radios, but I can not identify these old units. I picked them up overseas in SE Asia and I got them as projects to teach myself enough to challenge the Advanced Amateur Operators certification exam. I find hands on better than books all the time so these got my interest.

They are without battery packs or antenna so I need to replace/bodge alternates. I am not licensed to transmit in my current country but would like to revive these units. I am no expert and will learn by doing.

Public Utilities Act [220 ILCS 5/13-214 (a)] Public mobile services means air-to-ground radio telephone services, cellular radio telecommunications services, offshore radio, rural radio service, public land mobile telephone service and other common carrier radio communications services.

Public Utilities Act [220 ILCS 5/13-214 (b)] Private radio services means private land mobile radio services and other communications services characterized by the Commission as private radio services.

One of the most significant benefits of using HF and V/UHF radio communications is that this equipment can extend telephone communications far beyond the range of conventional networks without using costly satellite infrastructure. This means users can still establish contact in remote locations or where conventional communication methods are compromised, even over hundreds of kilometres.

What is HF radio-telephone interconnection?

This is the process of patching a radio connection into a public telephone connection. This enables radio users to make calls to any telephone number, and phone users to contact any station on your HF network. High-quality interconnection devices offer full network management facilities, including:

1. Dependable use in emergency communications

Operators use HF radio equipment because of its ability to provide reliable communications even in remote locations or areas where conventional communication methods are compromised.

Using an interconnection device such as the Barrett 2061 HF Phone Patch, operators will be able to make contact with any telephone number in the world, thanks to unique adaptive hybrid technology which converts four-wire transceiver audio to two-wire audio for the phone line.

3. User-focused and intuitive design

High-quality HF radio equipment has features for enhancing communication quality. HF radio-telephone interconnection devices often include digital signal processing (DSP) noise reduction, providing clearer reception.

Specifications can be changed to meet country specific requirements and those of local radio communications authorities. As such the specifications shown here may not reflect those of products distributed in some countries.

WALTER CRONKITE. Good day. President Carter and I are in the so-called Oval Office of the White House. We are in a couple of wing-backed chairs in front of a coffee table and in front of the fireplace. Across from us is the desk at which the President spends much of his day working; over to our left the large doors opening out into the beautiful Rose Garden of the White House, on a very nice spring-like day here in Washington.

This is a unique occasion, in the sense that it marks a new approach to communication between the President and the people of the United States. It is indeed historic--unique, historic--and we must also say an experiment since the President has never taken part before in this sort of a broadcast.

Now, here's the way we want it to work, we hope it works. We will receive phone calls from all over the country. We expect people to ask questions on many, many subjects, of course. There will be no censorship at all, no pre-screening in that sense. However, you should know that it is not going to be easy, of course, to get through, because there have to be just a limited number of lines coming to us here at the White House.

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