Это - достаточно беспорядочный архив сообщений конференций сети fidonet, которые на момент их прочтения мной
показались полезными или интересными. Многие устарели, многие узкоспецифичны и малоинтересны, но может оказаться и что-то новое...
- __techs (2:5015/42) ----------------------------------------------- __techs - Msg : 215 of 1000 From : Zahar Kiselev 2:5030/382 16 Dec 96 03:37:20 To : All 18 Dec 96 22:26:20 Subj : Еще пpо Радиомодемы ------------------------------------------------------------------------------- @AREA:SU.HARDW.SCHEMES Hello All! Вот еще пpо буpжуйскую pадиосвязь. У кого там онлайн-доступ в интеpнет? Сходите туда, куда указано в конце, посмотpите и pасскажите пpисутствующим. Here's some info on the latest modem: The VFast28.8 GMSK Radio Modem After over a year of work,the VFast28.8 GMSK Radio Modem adaptor has been completed. The VFast28.8 is a radio modem kit for AX25 packet radio users. The modem has been developed by G6WPJ and G8STW specifically for Radio Amateur use. The GMSK data modulation method used is proven in more than 1 million Digital Cellular Telephone units around the world. The VFast28.8 uses the latest in VLSI component technology. Feature List Data Signalling between 3600 and 38400 b/s. Simple plug on fit to most types of TNC. 'TNC 2' compatible 20 way connector on the circuit board. Fast receive 'lock on time' and Data Carrier Detect generation. Compatible with G3RUH designs when used at 9600 baud. PTT control circuits and watchdog timer included on the circuit board. Easy to use calibrate and setup signals. Audible Morse Code Ident generation to meet license requirements. Built in Data de/scrambler as per UOSAT-C, G3RUH and others. Low power consumption. Small circuit board (140mm x 60mm) with few components. Uses GMSK - The method of modulation used in Professional Radio Data systems. Operating Speeds The all new design can operate at the following speeds without component changes other than to select the correct master crystal. 3600 4000 4800 7200 8000 9600 14400 16000 19200 28800 32000 38400 Construction Board shown actual size (See GMSK.GIF in GB7OAR \\9600 directory) The board illustrated here is simple to construct and measures only 140mm x 60mm. It uses simple to buy componants with 4 IC's required. The VFast28.8 modem kit comprises a high quality pcb with full ground plane and careful analogue / digital separation, a preprogrammed microcontroller and a Technical Manual. The GMSK modem IC used can be obtained direct from the manufacturer. Full contact information is given in the VFast28.8 manual. Compatibility The design provides a neat solution to converting a 1200 baud TNC2 or similar TNC to high speed with the minimum of effort. The completed pcb fits onto the modem disconnect header of either a G0BSX, G8STW TNC2 PLUS, Paccomm Tiny 2, or many other TNC designs. It is also suitable for use with PC based expansion cards such as the Thor RLC200 4 port card and others. It additionally requires only 7 external wires to complete the installation. As a compatible type of modulation method and data scrambler is used to designs based on the G3RUH modem the VFast28.8 will interwork with G3RUH modems successfully. Documentation A fully illustrated 50 page Technical Manual is supplied with each VFast28.8 modem kit. This manual can also be supplied on its own at a small charge (refundable on purchase of the VFast28.8 modem kit) for those who wish to read a little before building the complete project. Further Information:- The Vfast28.8 GMSK High speed Packet modem. The Vfast28.8 is a radio modem kit for AX25 Packet radio users. This new GMSK modem has been developed by G6WPJ & G8STW specifically for use by Radio Amateurs. The GMSK data modulation method used is similar to the method used by the GSM digital cellular radio system. The Vfast28.8 uses the latest in VLSI component technology . Feature list. ------------- * Half Duplex Data signaling between 3600 and 38400 bits per second. * Simple plug fit onto many types of TNC . * TNC 2 compatible 20 way connector on the circuit board. * Compatible with G3RUH based designs when operated at 9600 bits per second. * Fast receive "lock on time" and Data Carrier Detect generation. * PTT control circuits and Watchdog timer included on the circuit board. * Easy to use Calibrate and setup signals. * Audible Morse code Ident generation to meet UK licence requirements. * Built in data scrambler / de-scrambler as per G3RUH and others. * Low power consumption. * Small Circuit board size (140mm x 60mm) with few components. The kit consists of the following :- A double sided PTH high quality PCB. A pre-programmed microcontroller. A 50 page high quality technical manual. Price is 39 UK Pounds Sterling in the UK or 45 UK pounds for overseas. The additional componants required should cost around 15 UK Pounds Sterling. The manual is available seperately for 10 UK pounds in the UK or 12 UK pounds overseas. The manual price is refundable against the cost of the kit. Prices include carriage. To find out more look at the following Worldwide Web page :- http://www.stack.serpukhov.su/~victor/hamradio/packet/vfast288.html (text of page is shown at beginning of this file) To know more please e-mail: matt@nuthatch.dungeon.com Thank you for reading this and we look forward to hearing from you. 73's de Matt G6WPJ and John G8STW. Yves Remedios Wembley IO91UN G4UDT @ GB7BST.#32.GBR.EU С уважением, Zahar ............................................................................. --- * Origin: GREEN SYSTEM (2:5030/382)
