Description
Integrated digital stereo signal generator, excellent audio, on-board RDS
The new STMAX 9000+ series FM exciters combine more features into a small board than ever before. With digital modulator, on-board stereo and RDS and all of this full controllable via LCD display with new 2-level MENU system and availability in 15W, 25W, 50W and 100W formats all powered from 12-15V this board represents realization of dreams for most prospective radio station builders.
The design is similar to MAXPRO8015+ and also looks quite similar at first glance, however it comes with on-board integrated digital stereo encoder with RDS. The result is a rugged and solid FM exciter with completely flat power output across the entire FM band at 15W, 25W, 50W or 100W designed to run silently 24/7. Since the new design featuring larger heatsink was so much better and completely stable we were able to add 50W and 100W models. Your dream FM exciter is a reality right now!
Manuals and drivers for most products are available under Additional Information tab above. When downloading drivers your browser might sometimes block the download and you have to allow it manually.
You can find the manual for some products also here.
How is STMAX9000 series different from the older STMAX3015 series?
– DIP switch mode supported, works also without LCD
– Greatly improved stability and reliability
– Massive heatsink for 50W and 100W versions
– Completely rewritten software
– Can be controlled entirely via RS232 (no LCD unit required for this) terminal or your control unit, see photos below.
– 0.5W power limit jumper (in addition to 1W, 2W, 4W and 8W)
– New better modern output stage
– Improved output filter
– BNC or MCX antenna output connector (N, SO239-CB and BNC pigtails are available, they plug into MCX)
– Firmware of RF board is now upgradeable (requires USB to serial converter – our RS323 IO board)
– Compatible with old STMAX3015 board, audio input board and display, they will work
How is STMAX different from MAXPRO series?
– On-board stereo and RDS encoders.
– Integrated digital stereo and RDS modulators. This ensures very good audio, but creates spurious artefacts about -50dBc
– All parameters adjustable from the LCD, including RDS RT, PS, PI and others
– MAPRO line is for professional setups, the signal in STMAX is not as clean
– Can’t be used with MPX STL links as there is no MPX input that MAXPRO series has
Technical specifications:
– RF Output Power: 0 to 15 Watts, 0-25W, 0-50W, 0-100W (fully variable via LCD in nice gradual steps), LCD power adjustment range can also be limited to 0-1W, 0-2W, 0-3W, 0-4W … 0-15W, 0-full, this is done with a jumper (exact options vary depending on model).
– Output connector: BNC female or MCX female
– Output Impedance: 50 Ohms
– Frequency range: 87.5-108MHz
– PLL Steps: 50KHz-500KHz, adjustable
– Frequency stability: +/- 20Hz
– Spurious/Harmonic rejection: Harmonics: >50dB, Spurious: >-50dBc
– Power Supply 15W: 12-15V/2.5A
– Power Supply 25W model: 12-15V/4.5A
– Power Supply 50W model: 12-15V/7A
– Power Supply 100W model: 12-15V/12A
– Power connector 15W, 25W (barrel type, center +), 50W and 100W model: New design with plugin with 2 screw terminals
– Quartz Locked PLL Frequency Control, DDS digital modulator
– No Expensive Test Equipment Required
– Audio performance: Less than 0.1% distortion, 20Hz-15KHz
– RF output ruggedness: SWR protection, temp protection
– Polarity protection, temp protection
– Pre-emphasis, 50uS, 75uS or none selectable via LCD
– Stereo pilot level adjustable via LCD
– RDS pilot level adjustable via LCD
– MPX level adjustable via LCD
– Audio Input Impedance: 1Kohm, unbalanced
– Audio Input Level: -10dBu, +4dBu (selectable from LCD)
– Stereo separation: >50dB
– S/N ratio: >90 dB
– PC Board Size: 100x125mm
– Audio connectors: 2x RCA jack, 14-pin connector for external input board with balanced XLR inputs
– RF monitor: solder pads
Controlling STMAX9000 RF board via RS232 terminal (LCD not required)
The RF board board can be controlled with your own LCD display or computer via RS232. All you need is a terminal, the command syntax is very simple. For this to work you do not need any LCD display unit as RS232 port is on RF board itself. The protocol is very simple, this photo explains it all. The pinout of the RS232 header is explained on the board itself. Here is the manual explaining controlling STMAX3015 micro through serial port.
Advanced graphics display with VU meter and web control interface
This is our new advanced high performance graphics OLED display with many incredible new features that older units did not support. First of all, it offers a large graphics OLED display, it connects to internet via Ethernet and than lets you control the unit via web browser (no windows software needed anymore), it lets you update firmware of the display and attached modules which before was not possible, each display comes with two-color bright VU meter, rotary button, and aluminum front panel with plexiglass. Advanced menu system lets you set everything either from the display itself or the web interface. This is of course an optional item. For extensive manual look down under Additional Information tab. Any questions send us an email.
What is the RS232/USB IO board and why do I need it? NOT NEEDED WITH OLED DISPLAY!
IO board is required, if you want to control STMAX9000+ remotely via PC. It plugs into the LCD control module and gives you USB port making it possible to connect STMAX card to PC computer and control it remotely. IO board is also needed to upgrade firmware of STMAX RF board.
OLED graphics display has its own IO board and does not require IO board! It has its own Ethernet adapter.
What is the Ethernet remote control module for? NOT NEEDED WITH OLED DISPLAY!
This add-on card lets you connect this transmitter to the PC via Ethernet network. You can control and monitor the status of your transmitter over Ethernet or Internet. This is of course an optional item. This card requires RS232/USB IO as it plugs into it.
Graphics LCD display has its own USB and Ethernet IO board and does not require extra IO board or ethernet module.
What is the Audio Input Board for?
This add-on card adds two XLR balanced inputs and two RCA connectors plus USB audio input. It also comes with extra low pass filter, limiter and a jumper for optional external audio input (from mp3 player or something else). The inputs are ESD protect and have RF filters. This is of course an optional item but it is highly recommended and it does make life easier as you can install exciter far from the audio input connectors. It will improve sound as well, sometimes dramatically.
There is also AES/EBU version of this board!
What is the Software+IOBOARD for changing logo?
This is a combination of special unlocked version of software and RS232 IO board, which is required to control STMAX9000+ remotely via PC/RS232. It plugs into the LCD control module. Software lets you change welcome text (logo); you can replace that text with your company name for example. Your customized text will be saved and used at every power-up. This is of course an optional item. Works only with classic LCD displays, not the new graphic OLED.
What is modification with software for 76-108MHz?
This is the microcontroller IC with modified software that enables STMAX units to work from 76MHz to 108MHz. In order to use this you have to remove original IC from LCD control module (it is in a socket) and place this modified. Immediately frequency range will be expanded. You can change back to the standard IC at any time. This item can be purchased separately and it will also work with STMAX units that you purchased in the past (unless they are really old). Make sure to take correct version for your display! Important: The LCD shows less power than there actually is available below 76MHz. Also actual output power may be a bit less under 87MHz, how much depends on the board but usually about 20-30% less at 76MHz. Also the LCD itself will show less power than there actually is being transmitted. So keep in mind that your display will show maybe 5W but 10-12W will be transmitted.
What is the Empty enclosure for STMAX9000 for?
This is a very practical enclosure with all holes predrilled. You can install the STMAX9000 inside. It even has a heatsink so it will accept even the 25W, 50W or 100W version. A fan is not included, use 80×80 fan. Holes for the LCD are predrilled as well. No text or brand name is printed anywhere on this box. Look at the video below:
What else should I buy to construct a big 1000W or 2000W or higher transmitter?
We really recommend these items to all users:
– Any of these pallets here, a power supply for these can be purchased here, don’t forget a filter (LPFMAX series is ideal).
– Stereo encoder, any of these will do. SE8000 is ideal due to MAXLINK II.
– A rack enclosure from 1H to 3H, with fans, accessories and more…
– Use PTFE RG142 50 ohm coax for internal connections inside your rack (PTFE coax is easier to work with, it does not melt when hot). Make sure all coaxial cable leads are very short.
To look for a suitable antenna check: here.
To look for a suitable coaxial cable check: here.
To look for a suitable case check: here.
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