Mechanics
The goal of this project is to build a user-friendly wideband receiver. We’ll modify a smartphone case (hereinafter referred to as a “smartphone case”) and mount the components to create a practical wideband receiver. The main components consist of the modified smartphone case, the SDR dongle bracket, and their assembly.
Three Types of Usage (Form)
With Trinity, you can choose which SDR module to use depending on the operational scenario. The available form factors are handheld, shoulder-mounted, and station-mounted. To achieve this, we use “magnetic piggyback mounting,” “sling mounting with snap hooks,” and “tripod mounting.”
| Handheld | Shoulder | Station |
|---|---|---|
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| Piggyback | Sling | Tripod |
| Compact Operation | Balancing Mobility and Isolation from Noise Sources (Smartphones) | Manage Carefully |
BoM
| Name | Specifications | Unit Price (yen) | Quantity | Where to Buy | Notes |
|---|---|---|---|---|---|
| Smartphone Case | For my own use | 719 | 1 | Amazon | Galaxy-A25 |
| Insert Nut | 1/4inch | 739 | 1 | Amazon | There’s quite a bit left over |
| Adhesive | Metamorphic Silicon | 378 | 1 | Amazon | If your phone case is made of TPU, go with this one |
| Snap hook | *** | 110 | 1 | 100-yen store | Depending on your preference |
| Double Ring | About 10 mm | 110 | 1 | 100-yen store | |
| Magnet | About 6 mm | 110 | 1 | 100-yen store |
Please procure any other necessary items as needed.
| Smartphone Case (After Processing) | Smartphone Case Parts | Bracket (Front) | Bracket (Back) |
|---|---|---|---|
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Assembly
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Completion of the Part
First, complete the components and prepare the parts to be attached to the case.-
Machining the Tripod Mounting Base
- 3D Printing the Tripod Mounting Base ()
- Press-fit the insert nut into the center hole using heat
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Machining the RTL-SDR Bracket Mounting Base
- 3D Printing the SDR Bracket Mounting Base ()
- Push the magnet into the hole, being careful to align the poles correctly.
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Customization of Smartphone Cases
The smartphone case will be processed after the above parts are completed.- Processing
Glue the tripod mounting base and the RTL-SDR (hereinafter referred to as “SDR”) bracket mounting base to the smartphone case. The choice of adhesive depends on the material of the smartphone case. Many smartphone cases are made of
TPU. Choose an adhesive fromTPUthat is primarily composed of modified silicone.
- Processing
Glue the tripod mounting base and the RTL-SDR (hereinafter referred to as “SDR”) bracket mounting base to the smartphone case. The choice of adhesive depends on the material of the smartphone case. Many smartphone cases are made of
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RTL-SDR Bracket
Since the bracket directly affects usability, there are various possible designs, but for now, we’ll go with this shape…- 3D Printing the RTL-SDR Bracket ()
The holes on the bottom are designed to fit the cables described on the hardware page with just enough clearance. If you use different cables, make sure to adjust accordingly! - Hot Press-Fitting Insert Nuts with a Soldering Iron
- Embed the magnets, paying attention to their polarity. If there are any gaps, fill them with adhesive as needed.
- Attach double rings or snap hooks as needed
- 3D Printing the RTL-SDR Bracket ()