nobcha23のABブログ

受信感度10dBNQ  To measure 10dBNQ sensitivity for DIY radios

The sensitivity specificattion for VHF AM radios is measured by 10dBNQ method. I tried to get the value by using tiny SA ultra, Adruino oscilloscope, and connecting circuit. I described the note how to check the value. WEBの情報(例えば自衛隊規格のNDSとか)を参考に、受信機感度の測定方法についてまとめてみました。手持ちのDIY機器とか部材を利用し、できそうな簡易的な手順をま…

2024/09/20 23:52

R909-DSP1/2のTA2003各端子デジタルテスター測定電圧値を比較し不具合要因を探る Comparing the measuring value with the data sheets.

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. After then I finally noticed that the trace of i2c-SDA was ne…

2024/09/16 23:24

R909-DSP1のスケッチと操作について About the R909-DSP1 Arduino sketch

The R909-DSP1 sketch is programmed into the ATmega328P using the Arduino UNO loader. There is a 6-pin header for a USB Serial module that connects to the Arduino IDE, allowing you to drop programs into the ATmega via USB Serial. In this article I will explain the operation reffering the display. R90…

2024/09/07 23:44

DIYエアバンド受信機(Si4732使用)の作り方 I would like to introduce R909-DSP1

Currently R909-DSP1 is a best my DIY airband receiver. R909-DSP1 is made of TA2003＋Si5351a+Si4732+LM386. I would like to introduce it in details. I uploaded the nessesary data on GITHUB. DIYエアバンド受信機のキット組み立て、改造、新規設計などを数機種手掛けてきました。その中で、今のところ、安定度・感度でR909-DSP1が一番だと思っています。作り方を説明します。この機種は回路設計、基板設計、スケッチ設計、…

2024/09/04 20:13