FASM1S5 is a professional FM PLL radio broadcast transmitter. It has excellent audio quality, adjustable RF out power (up to
1000W), easy menu using only four keys, 16x2 big LCD (white characters on blue backlight) which displays frequency,
FWD, REF readings, and modulation level, and many other features. Internal microcontroller circuit checks the whole unit and
provides various protections, among which VSWR protection, temperature protection, etc.
It has two audio inputs for the left
and right channels, which can be set as balanced or unbalanced by the user. Both inputs are pre-emphasized for either 50usec or 75usec
(user-selectable) for mono modulation. A third auxilliary input is available for connection of stereo multiplexed signals (unbalanced
BNC connector). Thru it, it can be modulated with a stereo generator signal for excellent quality stereo broadcasts.
There is a fourth input for whatever auxilliary signal such as RDS/SCA (unbalanced BNC connector).
You can either connect left and right audio at the rear balanced XLR inputs that can be used
either by the internal STEREO encoder or as a MONO selected signal, or feed it from an external
stereo encoder through the MPX unbalanced (BNC) input. You can also feed an external RDS (or SCA)
signal from an external source to the corresponding dedicated BNC input.
Note the transmitter comes with its own built-in stereo
generator as standard. This, however, will be automatically bypassed if you select so from the menu to work with your preferred
external stereo encoder if you so choose.
The transmitter is based on a FULL BROADBAND DESIGN with no variable caps or other adjustments!
Everything is done via the menu. Its frequency can be set anywhere from 87.5MHz to 108MHz (special model for 76-90MHz Japanese
band also available) and minimum step of 10KHz.
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. It is also possible instead of turning off to lower the RF output
power at the preselected levels (for day/night regulations and/or economy reasons). The transmitter has full remote control
and telemetry connectivity via a standard RS232 port, or optionally, via Ethernet.
From this you can remotely fully control and monitor the transmitter as if you were on-site.
For example, when the transmitter is working in a remote location.
All user settings including
the power-on frequency can be saved to the built-in non-volatile memory.
The unit meets all FCC and CCIR requirements for FM transmitters
but it has not been FCC certified. It has an excellent spectral purity with harmonics rejection better than -60dBc as can be seen
on a Spectrum Analyser, spurious output better than -80dBc, and accuracy of the VCO lock-on frequency of +/- 200Hz. RF output is disabled
when PLL is unlocked. You can also manually turn the RF output on/off.
FASM1S5 - Stereo FM Transmitter 1000W
Design and Development of Electronics and Software Systems