Blaster TeLetype (BTL) uses the Soundblaster card and a 386DX computer or better to receive and transmit radio teletype (RTTY). BTL uses DSP techniques to give demodulation performance exceeding that of most analogue RTTY modems.

RTTY is one of the simplest forms for data communications over radio, and has been around for something like 50 years. However this simplicity does not mean high performance is not possible, far from it! BTL can print readable text when the signal is barely audible amongst the background noise. SNR = -5 dB in a 3kHz bandwidth.

BTL is FREE for amateur use. But voluntary registration is encouraged to support the ongoing development of this program into a fully featured DSP multimode modem using only a PC and sound card.

BTL 1.51 FEATURES

• High performance RTTY Reception and Transmission using a Sound Blaster compatible sound card.
• Function key TX buffers with on-line editing while receiving simultaneously.
• Text file transmission, with the ability to include function key text, End of file, and End of transmission sequences.
• Word buffering during TX, allowing backspace editing during live transmissions.
• On screen tuning and level indicators.
• Fully adjustable centre frequency and shift, with selectable preset standards.
• User definable preset shift and centre frequency.
• Fully adjustable baud rate, 25 to 200 Baud.
• USB or LSB default Mark/Space polarity for receive and transmit.
• RXR Mark/Space tone reversal on receive
• Narrow/Wide tone filter option
• Unshift on Space (UNS)
• Selectable US or ITU2 Baudot standards
• Extended Baudot, HAMCOMM compatible
• All printable ASCII characters available with Extended Baudot
• Fixed case option for Extended Baudot decoding
• Upper or lower case toggle for received text
• Received and transmitted text logging to a file
• 43/50 line mode selectable
• Manually forced letters or figures shift during RX
• Manually forced New Line and Clear Screen on demodulation screen
• Demodulation pause key (Hold)
• Adjustable input sensitivity and output levels
• MIC AGC toggle and input selection
• Function states and settings saved between sessions
• Support for Sound Blasters version 1.0 through AWE32
• Compatible with most Sound Blaster compatible cards
• Sound Blaster parameter validation
• On-Line HELP!!!
• Bright Colours!