AVT5109 A

Popular radio-communication receivers are usually designed to receive several emissions and usually have simplified filters matched to receive the widest signal. For AM / FM modulation it is approx. 6 kHz, in single-ribbon receivers the filter has a width of 2.4-3 kHz. For telegraph signals this is too high - the operator's ear is exposed to a series of unpleasant sounds. The solution to the problem is to use an external audio filter. It makes the audio reception pleasant, regardless of whether it is SSB or CW.
The presented system has been developed on the basis of filters with a switchable capacity - MAX295 systems that can be obtained as free samples from the company MAXIM.

The device is especially recommended for amateur radio players

Selected parameters:

• frequency response 300Hz - 3 kHz
• out-of-band suppression of 96 dB / octave
• 10 dB signal amplification
• built-in voltage stabilizer
• 12 Vdc power supply
• tile dimensions 95x50mm
• printed circuit board and documentation included
  A version with a set of components for self-assembly is available
  A detailed description in EP 8/07