ASM100 (DDS-based AM C-QUAM Stereo Transmitter)
ASM100 is a professional grade CQUAM compatible Stereo, or Mono capable AM Medium Wave DDS-based (better than PLL stability) radio broadcast transmitter for broadcast use that offers great audio quality, 1KHz frequency selection (for both 10KHz US and 9KHz EU steps) using only four keys. RF output 100W (at 50 Ohm) maximum over the entire band. FULL BROADBAND DESIGN, no variable caps to adjust! Comes in a 2U rack-mount enclosure.
Frequency range: 530KHz to 1700KHz (other frequency ranges on request) and minimum step of 1KHz.
It has two independently adjustable audio inputs, for Left and Right channels with modified 50usec or 75usec pre-emphasis and low-pass filtering (depending on country).
Frequency is settable via a screen menu. All menu settings can be saved to the built-in non-volatile memory at the press of a key.
The unit meets or exceeds all FCC requirements for AM transmitters for the 100W power level. It has an excellent spectral purity with harmonics rejection better than -60dBc (due to the auto-selectable built-in filters) as can be seen in a Spectrum Analyser, out-of-band spurious output better than -70dBc, and accuracy of the lock-on frequency better than +/- 0.5Hz. You can manually turn the RF output on/off, or use the built-in real-time clock to set a daily or weekend schedule for automatic on/off at a specific time. With this option, one can leave the unit at a remote site and have it operate only for the specified hours.
A C-QUAM Stereo encoding system is built-in and provides crystal clear audio up to 12KHz (selectable internal low-pass filters for 4.5KHz, 7.5KHz, and 12KHz) and with a channel separation of more than 35dB. Optionally, this system can be de-activated via a menu selection in case you need to use the device as a Mono AM transmitter.
The unit is powered from any 110-230VAC outlet.
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