10W AM transmitter with DSP processing, PWM modulator and DDS frequncy generator
While for many mentioning AM transmitters brings back childhood memories, these are actually still used widely in some countries. Besides, AM can be lots of fun to play with. Long wire antennas, different signal propagation (even worldwide), the nostalgia that comes packed with it... well, it is something very different in this modern age.
Our old AM MAX units sold out many years ago and for a long time we wanted to make a new AM transmitter, this time with different, more modern approach, with new better parts and better specs. And we finally did. It is equipped with DSP which makes it possible to control parameters of the audio chain, such as the compression, low pass audio filter cut frequency and preemphasis via convenient LCD with menu system. Other features, such as the fully solidstate PWM modulator which ensures crisp audio, 125% positive peak modulation, compact form factor, plenty of audio input options and LCD display unit make AMMAX2000+ really something special in this modern age.
All our manuals are available here.
What is the audio input board:
- RF Output Power AM: 10-15W carrier (24V-48V DC stabilised, unit ships preset for 48V)
- Peak RF Output Power: 40-60W
- Output connector: BNC
- Output Impedance: 50 Ohms
- Frequency Range (MW version): 540-1710KHz
- Frequency Range (HAM version): 160m, 80m, 40m (ask for other bands)
- PLL Steps: 1KHz
- Frequency stability: +/- 50Hz (trimmer on the PCB for fine tuning)
- RF output: Harmonics: -50dB, Spurious: -80dB
- Power Supply: 48V/1,5A DC stabilised
- Wideband design, no tuning required
- Audio performance: compressor, low pass filter, limiter, treble, bass adjustment
- RF output ruggedness: > 2:1 VSWR
- Modulation: AM (CW is possible with a small mod).
- PCB size: 100x125mm
- Audio input: accepts either mono or stereo signal (transmission is mono)
- Audio connectors: 3-pins for GND, L and R signals. With audio input board you also gain XLR, RCA and USB audio input
- DRM support: On-board jumper can disable DSP processing which is great for DRM modulation
- Modulation: AM, 125% positive mod
- PWM circuit is opto isolated and can be used to drive high power external stage
- Audio input board adds XLR, RCA and USB audio inputs to the transmitter. It is also equipped with extra input limiter, low pass filter and balanced input stage with ESD protection. You may think this is not needed, but believe us it is nice to have.
Suitable DIY antennas for the AM transmitters:
Link 1, link 2, link 3, link 4, link 5
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