R909-DSP1はATmega328P+TA2003＋Si4732＋Si5351a＋LM386構成のエアバンド受信機ですが、その後R909-DSP2をシリーズに追加しデバッグ中です。R909-DSP2はATmega328P+TA2003＋Si4732＋Si5351a＋2822構成で3.9VLi＋電池対応です。今回は更にR909-DSP4のデバッグ…

I could not find the cause of backgound noise from TA2003 or the former section. I shall compare the measuring value with the TA2003 data sheet listed. I measured all nodes of R909-DSP1 and R909-DSP2. However I could not claer this isuue. …

I will introduce the R909-DSP２’s front end filter. I used the 2-stage stagger for R909-DSP1. This time I adopted 3 stage Chebyshev characteritic filter. It is sharply high cut but there is deep ripple. Please look at the last photo. R909-…

R909-DSP2 is a follower of R909-DSP radio and composed with TA2003＋Si5351a+Si4732+TDA2822. I scarcely finalised debugging it. After winding coils it receives the signal from the airplane who is approacing to Itami airport. It could not re…