The Ten-Tec RX-340 is a multi-mode, general coverage synthesized receiver utilizing extensive Digital Signal Processing. DSP brings the performance and repeatability of expensive military grade communications receivers into the price range of top end commercial receivers for shortwave listeners. Tunable from 5 kHz to 30 MHz, it provides tuning steps and display resolution of 1 Hz. All three displays are blue/green vacuum fluorescent and provide unparalleled contrast and readability. The RX-340 is a laboratory-quality instrument in its ability to quantify the amplitude and frequency characteristics of signals and receivers.
The performance level of receivers in this class is possible only through extensive use of Digital Signal Processing. These designs utilize fewer analog circuits than traditional receivers. Powerful, specialized DSP microprocessors replace many of the discrete circuits with intensive software containing over 60,000 lines of code. High dynamic range analog stages provide 1st , 2nd and 3rd I.F.s (and 80 dB of AGC) where signals then pass through analog to digital converters. Everything else is accomplished in DSP including all mode detection, I.F. filters, AGC (remaining 40 dB), adjustable BFO, passband tuning and noise blanker. An astounding 57 I.F. bandwidths from 100 Hz to 16 kHz are included. All filters have shape factor of 1.5:1 or better (6 to 60 dB). USB, LSB, ISB, CW, AM, Synchronous AM and FM are built-in. Four AGC modes are provided. Conventional Fast, Medium and Slow modes are familiar but the “Programmable” mode is groundbreaking. User may build their own personal AGC characteristic by selecting attack, hang and decay rates. Manual control from front panel is also adjustable over 120 dB range. A tunable notch filter rejects unwanted signals in the passband. Receiver front end incorporates built-in preselector with eight octave bandpass filters. Switchable 10 dB preamp and 15 dB attenuator are also provided. Signal strength meter is calibrated in both s-units and dBm.
