nobcha23のエアバンド受信機自作ブログ DIY airband receiver BLOG

エアバンドレシーバーキットの組み立て、改造を手掛けます Assemble and remodel Chinese airband receiver kit

GITHUBのR909-DSPのエラッタリストアップデート To update the R909-DSP errata list on GITHUB

こんにちは、R909-DSPですが、GITHUBにアップロードしました。時折、ダウンロードされているようです。

今回、作ってみたいが、疑問点ありますというメールをいただき、ご指摘内容を見直しました。その結果も含めエラッタリストを見直しました。

 

2SC3355ピン配置間違いを修正したら、感度が期待値の-100dBm以下となり、日々のモニターに使っています。後はOLED駆動ノイズと、RSSIモニタースキャンのノイズ対策が残っています。でもそれらはスケルチをかけた待ち受け時に気にならないので、改善意欲が今一つです。

 

OLEDのノイズですが、表示リフレッシュをかけると、ピョロローンとでます。OLEDは3.3V動作なのですが、表示素子駆動は10Vぐらいの電圧を使っており、3.3Vからチャージポンプで昇圧しているらしいです。そのチャーポン動作の供給電流でラッシュが流れ、電圧降下でノイズが発生するようです。

 

YOUTUBEを見ていると、チャージポンプやめて、直接7.5-15Vを供給するという対策がアップロードされてました。

www.youtube.com

 

 

試してみたいDIYエアバンド受信機キット

組み立てたり、改造したり、設計したりしたDIYエアバンド受信機キットを紹介しましたが、次はまだ試してないが、興味あるキット類のリストです。

試してみたい



エアバンド受信機キットの老舗?「套件之家」が供給するキットが色々と品種を増やしています。おととしぐらいR80のV6の回路に関し、問い合わせメールを出したんです。返事では新しいバージョンを開発しているから、そちらで対応すると言う返事が来ました。それで、何が出てくるんだろうと思ってました。

その後新規投入されたのはTEF6686使用のDSP方式製品だったようです。

 

PU2CLRのGITHUBライブラリーではまだ開発中でした。

 

 

現有エアバンド受信機の比較表

R909-DSPと名付けた最新DIY機の改版基板のデバッグ中です。ところで、この間紹介したように現有機5台があります。

nobcha23.hatenadiary.com

比較表を作ってみました。

有機比較

第一IFが10.7Mhzだと、初段フィルタでは118+10.7*2=139.4≒136Mhzがとり切れず、以前から何とかしたいと思ってました。R909-DSPはイメージ対策としてIFを21.4MHzにしています。そしてフィルタ挿入による感度低下を避けるため21.4MHzのセラミックフィルターを採用しました。そうなると、いわゆる帯域外領域のリジェクションにはSi4732には受信変調波帯域制限機能が効果あるのではと期待しました。PU2CLRライブラリーのAMは6kHzがデフォールトのようですが、帯域を狭めると高い音域が落ちるのが分かります。4kHzぐらいが高域音声ノイズ成分が低下し、通話音声了解度への影響度は少ないように思います。

 

新しく「8.333KHzステップ周波数設定」と、「Si5351a較正パラメーターのリアルタイム設定」の機能を作りましたが、R909-DSPには未組み込みで、近々追加の予定です。

 

 

以前からエブリチャンネルシークチェックを作ってみたいと思っています。ステップ周波数25kHzあるいは8.333kHzで全周波数帯をスキャンし、RSSIが一定値あるチャンネルを、連続なのか、テンポラリーなのかで、リスティング記憶しようかというものです。メモリーの容量がどれぐらい必要なのかによって、組み込み機能が変わると思います。面白機能を手掛けるにはArduino UNO互換ATmega328P+OLEDSSD1306では能力不足のようなので、ESP32+LCD*touchに乗り換えることも検討します。

 

R909-DSPを追試されたい場合はPCBGOGO登録でGITHUBにアップロードしたデータの基板を作成すれば可能です。組立説明書、エラッタ、スケッチも用意してあります。

www.pcbgogo.jp

 

 

 

 

 

Introduction to homemade air band receiver (4_4) R909-DSP(Si4732+Si5351a)

(This material is translated version.)

R909-DSP

The last radio I will introduce is R909-DSP. This receiver was designed and sketched by myself based on Jason's idea of the R909 receiver. I thought it worked for the time being, but there were some issues and items that were not achieved and I'm continuing to consider them.

Ever since I started this blog, I've been thinking about making an airband receiver using a DSP chip. This time it finally happened. The configuration is TA2003-Si5351a-Si4732-LM386.

When receiving Airband, the local oscillator from the Si5351a module is input to the TA2003 first-stage mixer section and converted to IF21.4MHz, and the Si4732 operates as an AM21.4MHz receiver. FM broadcasts are directly received by the Si4732 chip. For control, use ATmega328P with ARDUINO UNO loader installed. The operating style uses a rotary encoder and switches to select functions, set parameters, and memorize parameters by double-clicking the switch.

The block diagram of R909-DSP

This receiver has two boards. The CPU, operation switches, and OLED are mounted on the PANEL board, and the front end, Si4732, LM386, and Si5351a modules are mounted on the RF board.

 

2PCBs

 

The PANEL board alone can also be used as a digital VFO for modifying analog station receivers, etc., and an additional Si5351a module can be mounted on the PANEL board. I also created a DEBUG-PANEL board to which WE1602A can be attached during debugging. This debug panel board was used to convert the Chinese Airband receiver kit (No. 1) into a digital VFO. The OLED display is at the limit of the ATmega328P's memory capacity, so the 1602A display is easier to use when tinkering with sketches.

Remodeled the Chinese airband receiver kit


Furthermore, the RF board has a pin header that allows you to add an ADX front-end filter board to the front-end section. I'm thinking of experimenting with an HF band DSP receiver in the future.


I have uploaded the related data of the three types of boards explained above and the current version sketch of the receiver to GITHUB.    

As an example of how to use it, I have uploaded it to YOUTUBE.

www.youtube.com

 

In addition, the width of the RF board has been made 83.5mm so that the RF board can be slid into the drawn aluminum case. In that case, combine it with an OLED version panel. The front and back panels of the case are made from circuit boards, making it neat and compact.

 

Selling case on Aliexpress

 

Introduction to homemade air band receiver (3_4) R909 kit(TA2003+Si5351a)

Next up is the R909 kit. This kit was developed by JasonKits. JasonKits is running as an e-commerce site by Ham on the island of Malta, which sells a variety of electronic circuit boards and kits. In the area of hams, he is distributing open source boards.

www.youtube.com

 

R909 is similar as the RF circuit of R80 V7, and the VFO control part was independently developed using Arduino. The sketch adopts function selection control using a rotary encoder and switch, and incorporates my No. 2 machine sketch. Because of that connection, I cooperated with debugging.


The TA2003 used is a chip that was used in 100 yen shop radios a while ago, and was a favorite among Japanese radio hobbyists. Toragi has published a book about designing radios using TA2003. Written by JA9TTT. AM/FM radio & transmitter production collection (CQ Bunko).

 

 


What makes the R909 unique is that it uses a TA2003 instead of a mixer such as the NE602 in the double super first mixer section, and the other TA2003 is configured as an AM/FM radio after the first IF.

 

ブロックダイヤグラム

There are some problems that have been dragging on since the R80 V7. Two relays are used to switch the AB and FM front end filter sections and to switch the parent radio's AM/FM. However, since the TA2003 switches the AM/FM input using an internal circuit, there is no need to externally switch the TA2003 input signal. Rather than that, the problem is that the external switch is left open when not in use. Especially in the AM position, the high gain FM side circuit input is open, causing oscillation. I found this out when MR.RADIO KITS IN JA pointed out this. Thank you for letting me know.

 

R909 has a double super radio with 1st IF: 10.7MHz-2nd IF: 455kHz, and a single super with IF: 10.7MHz for FM broadcasting receiver. The first IF is 10.7MHz, which is the case with all Chinese airband receiver kits, R80 and R909. This is caused by the availability of ceramic filters and discriminators for FM broadcasting, but images cannot be removed. In airband reception, if you set the upper heterodyne at 10.7Mhz-IF in the 118-136MHz band, the image will be at 118 + 10.7 * 2 = 139.4Mhz, which cannot be removed by the front-end filter. Therefore, I think it would be better to use an IF such as 21.4MHz for airband receivers.

 

The R909's display is a 2-line LCD with 16 characters, but I also tried making a modified prototype that switched to OLED 128x256.

 

 

Introduction to homemade air band receivers (2_4) R80 kit

(This material is translated version.)

Next up is the R80 kit. This kit seems to be developed and manufactured by the same manufacturer as the first model.

R80 front view

 

Mr.kon has reported of kit assembly on his blog. I asked Mr.kon some questions, bought a kit, and assembled it. Thank you for his cooperation. 
(⑲ Manufacture the Chinese AIR band receiver kit (R80 Aviation Band PLL Receiver Kit Aviation Radio Aircraft Tower Call DYI kit))

 

An English version manual made by ZL Ham is being distributed. When assembling the kit, we created a Japanese translation of the assembly operation manual using the English version of the manual as a reference.

https://nobcha23.hatenadiary.com/entry/2021/09/20/191923 https://nobcha23.hatenadiary.com/entry/2021/10/03/214015



 

By the way, there are two versions of R80: V6 and V7. I bought the V6 and assembled it. These two have completely different circuit configurations. V6 has the configuration NE5204-NE602-TA7640-MC3361-FM62429-LM386.

The block diagram of R80

 

I think the sensitivity is good because it is a double super and has an LNA. However, Skelch is unstable, so it's noisy when used as a standby monitor. I tried modifying it.

 

On the other hand, V7 has the configuration TA2003-TA2003-FM62429-LM386.

 

 

I put it in a case 88x38x120 made of drawn aluminum. Which is sold on AliExpres.

航空機タワーコールレセプションR80航空バンドPLLレシーバーキットダブル周波数変換ラジオAmazon

 

 

Introducing my DIY radio kits.(1 of 4)

(This is translated material.)
I think there are many people who buy air band receiver kits from Amazon etc., assemble them by soldering, and then use them.
I made it, tried running it, but thought it wasn't good enough, so I ended up putting it in the junk box.


Although it is affordable, it is a kit that requires some time and effort to make adjustments after soldering. You can just assemble it and use it as a side dish, but if you put some extra effort into it and start from a digital VFO optioned, it will transform into a cool receiver that rivals commercially available airband receivers.

Here we will introduce the assembly, modifications, and improvements of the receiver, which we call Unit 1. This project requires skills such as soldering, wireless knowledge, Arduino sketch development, and aluminum case processing.

I have explained each part several times. I recently ported the latest self-made version of the R909-DSP control sketch to this receiver (unit 1), so I decided to organize the information to my memory.

The remodelled Chinese airband receiver kit


First, the approach to assembling and putting this receiver together involves the following steps.

 

1. First, buy a kit from Amazon or Ali Express and assemble it.

 

2.Assemble a board named R909-Panel board as a digital station generator, which includes Arduino, digital station generator, board connection circuit, and display section.

 

3. Make modifications such as importing from external stations, improving LM386MUTE, and extracting AGC.

 

4. Process the aluminum case and attach the switch and LCD.

 

5. Assemble and wire the radio board, PANEL board, Si5351a module, LCD, and switch.

 

6. Write the sketch to Arduino pro mini or ATmega328P using Arduino IDE.

 

The following explanatory documents are available as a reference for the above work.

Abstract

Assembly manual

Squelch modification

Schematics for incoming LO signal

modification

Case in

Operation

 

How to design the sketch
If you would like to get the latest version, please ask me via mail.

The information of Debug Panel PCB

The note for PCB of R909-Panel

Inside the case

Block diagram