hal fax 4100 fax over radio

THE HAL FAX 4100 - SEND YOUR FAX OVER RADIO
Send FAX images without need of phone lines or satellite communications! The FAX-OVER-RADIO product line integrates a standard facsimile FAX machine into your high frequency radio system. The HAL FAX-4100 connects between your FAX machine and our DSP-4100/2K radio data modem. The only connection required to the FAX machine is the standard RJ-11 phone connection. We do all the rest, including our own fully compatible phone interface. Installation is very simple!

Once the cables are connected
Sending a FAX via your radio is even simpler
Lay your page on the FAX machine
Enter the ID number of the distant station
Push GO on the FAX machine

THE HAL FAX 4100 - SEND FAX OVER RADIO
The FAX-4100 accepts your call, decodes the dialed station number, and instructs the DSP 4100 2K modem to link with this station via the HF radio. The FAX-4100 then links with your FAX machine and receives, decodes, and stores the page to be sent. Once the CLOVER-2000 ARQ link is established, the stored FAX data is passed to the DSP 4100 which then sends it to the distant station. A DSP 4100, FAX 4100, and FAX machine at the other station reverses the process. Obviously, the same procedure can be used in the other direction to receive a FAX at your station. A page of business correspondence can be sent in 2 to 10 minutes, depending upon ionosphere conditions and density of the page to be transmitted. Best of all, the FAX operator need not know nor care that an HF radio system is part of the FAX link.

It all works just like a standard FAX telephone transmission! Put the radio stuff in a closet and don't worry about it! The FAX-4100 directly interfaces to any standard Group III G3 telephone FAX machine. We provide ring signal, off-hook loop current, dial tone, and DTMF tone decoding. At the start of each FAX connection, the FAX 4100's internal FAX modem negotiates data rate and other communications parameters with your FAX machine. On the radio modem side, the FAX-4100 includes the normal link and control commands used by the HAL DSP 4100 2K modem. When you initiate a FAX transmission, the FAX 4100 decodes the dialed number, sends it to the DSP 4100 as a call sign, and instructs the DSP-4100 to start CLOVER 2000 ARQ link procedures. Once a satisfactory ARQ link is established, data from the FAX machine is passed to the modem for transmission via radio. It's one efficient and integrated system.

DUAL USE OF YOUR FAX MACHINE
Want to use the same FAX machine in land-line service as well? NO PROBLEM Add the HAL LI-4100 Line Interface between the FAX machine and the FAX-4100. The LI-4100 is a smart switch that connects the FAX machine to the FAX-4100, or to 2 telephone lines. When sending, simply add a number to the start of your dialing sequence #0 for a radio link, #1 for line 1, or #2 for line 2. The LI-4100 and FAX-4100 decode the DTMF tones and direct your call to the designated connection. On receive, the LI-4100 listens for ring signals from all three sources - radio, line 1, and line 2. The first data line to ring is answered and connected to the FAX machine.

The other two ports are set to off hook condition and will ring busy to all other calls for the duration of the present FAX call. The expanded system looks like this. It's still a very simple hook-up, isn't it? Note that all data line connections to the LI-4100 use standard modular phone connectors and cables. The LI-4100 uses only components that are specifically approved for direct connection to a Public Switched Telephone Service. All circuits are heavily isolated from the phone line and the relays are type-accepted for switching of telephone circuits. The HAL LI-4100, FAX-4100, and DSP-4100/2K are designed to operate as an efficient and fully integrated system. This is not a system that is patched-together from various pieces of equipment. Rather, each HAL unit is designed to work with the others and each unit takes full advantage of the capabilities of the other.

SYSTEM COMPONENTS
The HAL FAX-OVER-RADIO System is simple and makes maximum use of your G3 FAX machine and SSB HF station. Add the DSP 4100 and FAX-4100 and you're on-the-air with FAX. Virtually all modern SSB HF transceivers may be used for FAX. The 500 to 2500 Hz spectra of CLOVER-2000 is directly compatible with SSB radio passbands. Special bandwidth filters or super phase-linear filters are not required. The +50 Hz frequency tolerance is compatible with virtually all modern synthesized SSB equipment. Standard 100 Watt transmitters and simple antennas 1/2 wave dipoles or 1/4 wave verticals are all that is needed for most FAX OVER RADIO links. Note that all HAL units operate from nominal 12 VDC 10 to 18 VDC in fact. The HAL FAX-OVER-RADIO system is a very good choice for either fixed or portable/field installations.

COMPUTERS AND OTHER EXPANSION
Notice that the basic FAX-OVER-RADIO system does not require a computer at either end. All control functions and data communications are handled within the HAL FAX-4100 and DSP-4100/2K devices. This makes for a very low-cost and simple system for those remote areas where a computer is not required nor desired. However, a computer can easily be added to the communications link. This permits use of the CLOVER-2000 link for all forms of data in addition to FAX. If you wish to design custom software, the computer may also be used to further compress FAX data, communicate with the radio control port, or to perform other control functions. The DSP-4100 includes a second serial I/O port which may be used to connect to the control port of the HF radio, eliminating the need for a second serial port from the computer a serious problem for most lap-top PC's. Standard phone line and data circuit connectors are used to keep installation simple, even for a full blown system.

SPECIFICATIONS FROM THE FAX 4100
Interfaces between a standard G3 Facsimile FAX machine and the HAL DSP-4100/2K modem. Includes simulation of all phone line signals required for proper operation of the FAX machine. In transmit mode, intercepts DTMF number from FAX dial pad, commands ARQ link via DSP-4100, handshakes and stores data from FAX machine, passes data to DSP-4100 as required, ends radio link and disconnects FAX machine when FAX has been delivered. On receive mode, accepts call from DSP-4100 and radio link, rings FAX machine, senses off-hook, handshakes, and passes data from DSP-4100 to FAX machine. In addition, when used with LI-4100, reads DTMF number sent from FAX to select outgoing line radio, line 1, line 2.

LI-4100
Interfaces between the G3 FAX machine and the FAX-4100 FAX-OVER-RADIO Interface. Provides electronic switching of FAX machine between radio and up to two standard telephone lines. Controlled by and requires FAX-4100 for proper operation. When sending a FAX, dial pad entry specifies outgoing link - #0 radio, #1 phone line 1) or #2 phone line 2. When receiving, senses ring signal and connects FAX machine to the calling port. Non-selected ports ring busy.

DSP 4100 2K
Digital Signal Processor DSP modem for use with high frequency HF radio equipment. Use CLOVER-2000 waveform and protocol to provide data communications between two locations. The waveform and adaptive ARQ protocol provide for continuous real-time optimization of modulation mode. The modem interfaces between an SSB HF transceiver and the FAX-4100 FAX-OVER-RADIO interface. See separate DSP-4100/2K data sheet for full specifications.

CLOVER 2000
Voice bandwidth digital communications waveform and protocol for use with HF SSB equipment. Auto-adaptive ARQ continuously corrects for measured changes in the ionosphere-conducted radio signal. Transmit modulation is dynamically adjusted to maximize error-corrected data throughput from 200 to 2000 bits/sec. FAX data sent at rate of 1 page in 2 to 10 minutes, depending upon page density and ionosphere conditions. See separate data sheet for full specifications.