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Yahoo Bid Hobbies & Crafts Wireless Devices Receivers
FR-50B 整備・アップグレード済
        

  • Product Quantity
    : 1
  • Starting Bid
    :20,000円
  • Highest Bidder
    : tmktp@admxtpgatp / Rating:335
  • Listing Date
    :2025年12月21日 08時16分
  • Bidding closes on
    :2025年12月28日 20時09分
  • Auction Number
    :u1213179869
  • Condition
    :Damaged and stained (specify in description)
  • Automatic Extension
    :Yes
  • Authentication
    :Yes(Description)
  • Early Closing
    :Yes
  • Can I return the product?
    :no
  • Description
  • Q&A ()
  • Cost Estimator
  • Problem Item Response Procedur
Notes
  1. Radio communications related products (import and export documents required) cannot be assisted in importing.
八重洲無線製のアマチュア無線用受信機です。
以前にもFR-50Bを出品しましたが、これは別の個体で手持ち2台のうちの2台目(最後の1台)です。

FR-50Bは、3.5MHzから28MHzの旧ハムバンドをカバーします。

内部外部ともに汚れやホコリを取り除き、各部の電圧測定・波形観測、伝達関数測定などを行い、経年劣化などによる交換が必要な劣化部品や故障部品を多数交換した上で調整を行ってありますので、良好に動作します。

将来の整備や修理などについても対応させていただきますので、ご安心下さい。
その場合、事前にご連絡をいただき、状況やご希望を伺った上での対応になります。

元々は調整が大きく外れて正常に動作していない状態でしたので、徹底的に修正・調整・測定・評価を行い正常動作に復帰しています。
また、設計的に特性を悪化させてしまっている部分も何点か設計修正し、特性を改善してあります。

尚、写真ではわかりにくいのですがケースやフロントパネルなどにはキズやヨゴレがあります。
出荷時のフロントパネル保護用プラスティックフィルムは既に取り外された状態です。

FR-50Bは、IFフィルタに日本製のメカフィルが使用されていますが、特性が優れていない(切れが悪くロスが大きい)ため、実用面では今一歩と評価された受信機です。
それではよろしくありませんので、日本製メカフィルを除去・廃棄しコリンズ製のメカフィルを実装しました。
コリンズの新型タイプのプロ用メカフィルを使用しましたので、旧型タイプ(Sラインや75A-4などに使われたもの)とは異なり、フィルタの切れが良く、ロスも少なく特性が優れています。

下の写真は、元々実装されていた日本製メカフィルの特性実測結果です。
最初は実測データを見て冗談かとも思ったのですが、別の個体3個を実測しても同様な特性でしたので、
マジかも知れないと気づきました。

The



シェープファクタが大変優れておらず、帯域外の減衰が30dBほどしかなく、またパスバンドもカマボコ型的です。

一方、下の写真は現状実装してあるコリンズ社製メカフィルの特性実測結果です。

The



文句ない特性です。 メーカーの技術差かも知れませんし、そうではないのかも知れません。

下の写真は、オリジナルのフィルタ(日本製メカフィル)が実装された状態で、アンテナ端子に微弱信号を入力した場合にスピーカ端子に得られた信号のスペクトラムです。

The



1632Hzにあるのが信号で、それ以外のものはノイズ成分です。 このノイズ成分のスペクトラムには、IFフィルタの特性が反映されているのが分かります。

一方、下の写真は、コリンズのメカフィルを実装しマッチング等を最適化した状態で、アンテナ端子に微弱信号を入力した場合にスピーカ端子に得られた信号のスペクトラムです。

The



IFフィルタの切れが良く、パスバンドも平坦であることが反映されてます。
パスバンド特性の点においては、FR-DX400やFT-101、或いはR-4Cや75S-3Cなどよりも明らかに優れています。

尚、この写真はアンテナ端子に0.1μVの微弱信号を加えた場合の特性です。
整備後の受信感度実測値は、0.25μV信号入力時に、S/N比18dBと優秀です。

メカフィルをコリンズ製に変更し各部の特性も改善したところ、外部スピーカ接続時に中々良い音で受信できたので、定量的に特性を測定してみた結果が下記の写真です。
アンテナ端子にキャリア信号(シングルトーン)を入力した際にスピーカ端子から出る音のスペクトラム(歪特性)です。

The



歪率は約1.5%と優秀です。

落札者には取説の電子ファイル(CD)を差し上げます。


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Product Price JPY
Japanese Consumption Tax(10%) JPY

A 10% consumption tax is applied to goods and services in Japan. The price may include the tax or it may be added separately. Please check the price details when ordering.

Note: This is a domestic sales tax applied within Japan.

Japan Local Shipping Fee JPY Japan Local Shipping Fee Reference
Product Weight KG The maximum weight limit is 30 kg
International Shipping Methods
Singapore Package Import: Customs and Tax Policies
Proxy bidding and purchasing services are becoming increasingly convenient. However, overseas shopping carries certain risks and issues. To reduce these risks and enhance shopping safety, please be sure to read the following information:

1. International Shipping

   Air Freight: If the item status is not confirmed within two days after the arrival notice, any customer complaints cannot be addressed with the seller.

2. After Receiving the Product

Please confirm and inspect the product as soon as possible to ensure that the product specifications, quantity, accessories, and description are correct

If, unfortunately, there are any issues, you can refer to the following examples on how to report related product problems:
1. Example of missing product information
2. Example of product not matching provided information
3. Example of damaged product information

Important Notes: 1. If the seller is unwilling to ship overseas or is unaware that the product will be shipped overseas, the international shipping cost for returns or exchanges will need to be borne by the member. You may refer to the EMS e-Express fee inquiry from the post office. If it involves alcoholic beverages or items that affect flight safety, the post office cannot be used for shipment, and only DHL can be used to ship back to Japan.
2. During the product complaint handling period, please retain the complete outer packaging of the product (including the shipping label information), and refrain from attempting any repairs or altering the original condition. Any modifications may result in the inability to process the case.

3. After Inspecting the Product

After receiving and inspecting the item, if you have any questions, it is recommended to contact Letao within 2 hours. Here are some reminders:

1. Please do not unpack, use or repair the received item yourself, and be sure to keep the original packaging to facilitate subsequent handling of related matters, so as to avoid changes to the item that may cause the seller to be unwilling to process.

2. You can call customer service, and the customer service will leave a message for you as below. Please provide the following information:
"Hello, we will first help you establish a complaint case for Product ID: _______ .But we need you to 2-3 clear photos of the product issue, including photos of the product problem, product packaging, shipping details slip, and outer box. Send them to service@letao-holdings.com and inform us of your desired resolution (failing to provide this may result in an inability to process subsequent matters). After sending the email, notify us in the customer service message. We will confirm with the seller as soon as possible. and if there are any related questions, we will contact you through the customer service message. Thank you for your cooperation."

Please provide:
1. "Product ID"
2. Photo of the "Delivery Note" (if any)
3. Photos of the outer box (including inner and outer packaging)
4. Photos of the product (Please include relevant descriptions to help us confirm with the seller)

Important Notes:
1. Do not include foreign text or other products in the background of the image.
2. Please keep the complete product packaging (including the shipping label information), and refrain from repairing or altering the original condition on your own, as any changes may result in the case being unable to be processed.
3. Please provide the relevant information within 48 hours to avoid missing the golden hour for reflection and causing situations that cannot be handled.
4. Due to 99% of Japanese sellers being unwilling or unaware of shipping goods overseas, if a seller is willing to handle the issue, the goods must be sent back to Japan, and the international shipping costs incurred must be borne by the member. Letao will use postal EMS international express to send the goods back to Japan.
5. As the goods are purchased from overseas, it may take approximately one to two weeks to complete the relevant processing procedures when issues arise with the goods. Please be reminded that you can inquire about the approximate cost through the EMS service at the post office.

4. FAQ

1. Issue of Authenticity: If antique or branded goods are found to be counterfeit upon receipt, clear photos showing the differences between the genuine product and the imitation must be provided as evidence. If unable to provide relevant proof, assistance can be sought to find a third-party reputable organization for a premium authentication service .
2. Leaking Iron Teapot: If an antique iron teapot is leaking, please take clear photos of the leaking area and provide them.
3. Transport Damage: If the goods are damaged during international shipping (to the pickup point), you need to provide photos of the outer packaging of the parcel and clear photos of the damaged goods' outer packaging.

※ Note: Photos provided to sellers should not contain any foreign-related information.
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    Product name: FR-50B 整備・アップグレード済
    Notes:
    Customer service hours:
    • Monday to Friday 10:00-18:00
    Customer service hotline:
    Customer Service Email: service@letao-holdings.com