DDS Frequency Synthesised AM Band DRM Transmitter

SKU: 112009




The ASPiSYS DRMAX100 range of medium-power DRM MW (AM band) transmitters.

All models in the range achieves extremely high stability thanks to the latest technology DDS-based frequency generator, which provides better stability than
that, typical of PLL-based systems.

To operate, you must connect it to your wall outlet AC 220-240V or 110-120V (factory preset) with an appropriate power cable. AC input voltage is adjustable via an internal switch.

To avoid damage, always operate the unit with the RF Output connected to a 50 Ω antenna, or ‘dummy load’.

Connect your audio source to the corresponding Left (1) and Right (2) BNC front connectors, or to the rear XLR if you have a balanced audio feed.

The recommended encoder software for your PC is ‘SPARK DRM Modulator’ which you can download as freeware from, which works extremely well. (This information is only provided for your reference. We have no ties with this company or site.)

Note: the freeware version supports monophonic DRM broadcasts because it uses conventional audio encoding, while the licensed version supports full DRM stereo quality as used by professional stations. More details can be obtained from SPARK’s website (listed above).

Technical Specifications

Subject to change without notice

RF Output Frequency 530 to 1710 kHz (Special versions may vary according to requirements)
Minimum Step 1 kHz
Frequency Accuracy +/- 0.5 Hz max. (DDS based)
RF Output (DRMAX100-5) 5 W dig avg (adjustable from 0.1 W) @50 Ω
RF Output (DRMAX100-25) 25 W dig avg (adjustable from 2 W) @50 Ω
RF Output (DRMAX100-50) 50 W dig avg (adjustable from 5 W) @50 Ω
Output Impedance 50 Ω
Harmonics (out-of-band) -60 dBc or lower
Audio I&Q Level Control Adjustable for unbalanced input
RF modulation DRM I & Q pre-encoded System
Input Level 0.15 V up to 2.5 V p.p. (adjustable unbalanced)
Input Impedance 10 KΩ unbalanced, 600 Ω balanced
Shoulder Suppression 45db or better
IMD -47db @ +/-30KHz
Operating Voltage 115 or 230 VAC (according to country)
Current Consumption DRMAX 0.5A max (100-5), 1.5A max. (100-25), 5A max (100-50)