Overview

1. The DDS-VFO

Fig. 1: Block diagram of the DDS-VFO

• Frequency range from 0,500.0MHz to 39,999.9MHz
• Possible frequency steps are 100Hz, 1kHz, 10kHz, 100kHz, 1MHz
• Power range from -40dBm to +10dBm (-40dBm, -30dBm, -25dBm, -20dBm, -15dBm,
  -10dBm..+10dBm in 1dB steps)
• Harmonics rejection at +10dBm output power better than 40dBc
• Microcontrolled (firmware flashable)
• 16x2 LC display with LED backlight
• 5 button keypad and rotary dial
• Idicator LED and beeper
• Generator and receiver mode
• Adjustable IF (1kHz..460kHz) in receiver mode
• Fixed output power (+7dBm) in receiver mode
• "One-touch" switchable LO shift (above or below fr) in receiver mode
• Automatic save of the all parameters after 3 seconds
• Remote frequency control via RS232 (acts as a Yaesu FT-817)
• Slot for extension (e.g. the DRM receiver frontend)

2. The DRM receiver frontend

Fig. 2: Block diagram of the DRM receiver frontend

• Input frequency range from 0,5MHz to 30MHz
• FET preamplifier for short antennas
• Double superhet (1st IF 455kHz, 2nd IF 12kHz)
• Output amplifier and buffer for direct connection to a PC soundcard (line in)
• For use with a DRM decoding software (e.g.DReaM)