All Digital Transceiver ADT-200A by HB9CBU part II. - First short performance tests

Subject: Receiver performance comparison

This experiment compares the basic receiver performance of the ADT-200A with known reference unit on the same antenna. Settings on both units: Band: 20m Mode: CW BW: 200Hz NB: OFF Notch: OFF AGC: fast AGC threshold (ADT): -80dBm

https://youtu.be/M7_gULhDwaU?si=dKPX4cNS3BLiPCdO Results: ADT receiver sounds much more selective as same as the BDR sounds better for close-in signals on the band. Signal S9 +40dB in the pileup just 1kHz away sounds strange on KX3 compared to ADT where it is also hearable but much weaker...

Subject: Receiver performance initial test This experiment shows receiver performance of the ADT-200A with different AGC and filters settings. Settings: Band: 20m Mode: CW BW: 50 - 500Hz NB1, NB2: OFF Notch: OFF AGC: fast AGC threshold (ADT): -80dBm Attack: 2ms Hold: 100ms Decay: 500ms

https://youtu.be/1SUs4nJdr6k?si=Tjujl6shEIGKenY3 Results: Amazing selectivity and high BDR for close-in signals, beautiful sound with smooth low-noise at -80dBm AGC threshold. Narrow filters are so effective that station need to be tuned quite precisely.

More info here:

ADAT page         - ADAT by HB9CBU

ADT-200A manual   - Microsoft Word - Operating Manual_1.35_en.doc

73 - Petr, OK1RP