# Harness fabrication and routing

The main PCB stays unchanged. Build non-battery harnesses on the bench; preserve the battery and RF factory cable assemblies. Use the named CAD volumes and routing figure together. Colors in the CAD are illustrative, not an electrical pin map.

## Required cable construction

| Interface | Construction |
|---|---|
| J2 battery | Original factory JST-PH plug/leads; no cutting, splicing, recrimping, unwrapping or protection changes. Modeled wire OD1.5mm. |
| J3 microphone | JST05KR-D6S-P transverse-exit PH-compatible housing, factory/professionally IDC-terminated26AWG7-strand UL1061/UL1571, insulation OD0.9–1.0mm.9mm catalog mated height. An ordinary upright PHR-5 or a CK housing is not this part. Obtain the specified cable before relying on this layout. |
| J10 speaker | PHR-2 with two SPH-002T-P0.5S contacts,28AWG stranded UL1061, OD0.8–1.0mm. One-piece leads; replace only at speaker terminals if the supplied wire is thicker. No inline splices. |
| J9 buttons | PHR-5, five SPH-002T-P0.5S contacts;28AWG stranded UL1061, OD0.8–1.0mm. Four signal wires plus one shared return junction and four branches. |
| J8 LED | PHR-4, four SPH-002T-P0.5S contacts;28AWG stranded UL1061, OD0.8–1.0mm. Individual insulated joints on the LED leads. |
| J5 RF | Existing150mm,OD1.37mm cable and MHF I plug. Do not shorten. Unplug by the connector with the board supported. |
| J7 USB | Existing cable opening; modeled shoulder design limit11.5x6.5mm with rounded corners.11.2mm width is photo-derived;6.5mm height is a design assumption. Test full seating without forcing. |

## Electrical connections

| Connector pin | Destination |
|---|---|
| J2-1 / J2-2 | VBAT_CELL / GND; verify actual received polarity. |
| J3-1 /2 /3 /4 /5 | MicVDD /GND /BCLK /WS /DATA. Installed breakout rowX=-6.35,-3.81,-1.27,+3.81,+1.27mm respectively. WS and DATA cross in the modeled harness. |
| MicSEL | Separate jumper toGND for the modeled left-channel selection; confirm firmware selection before final termination. |
| J9-1 /2 /3 /4 /5 | PTTGPIO38 /volume-upGPIO39 /volume-downGPIO40 /play-wakeGPIO7 /commonGND. |
| J10-1 / J10-2 | SpeakerP /N. Neither lead is ground; amplifier output is differential. |
| J8-1 red | Kingbrightphysical lead1. |
| J8-2 green | Kingbrightphysical lead4. |
| J8-3 blue | Kingbrightphysical lead3. |
| J8-4 GND | Kingbrightphysical lead2, common cathode. |

**Do not confuse J8 pin4/GND with LED lead4/green.** Verify housing pin1 against the board and continuity-test every completed harness. Four-leg switches contain two internally common pairs; select opposite pairs, checked with the switch released and pressed. Never infer the pair solely from appearance.

## Lengths and termination procedure

The length below is the CAD centreline outside the connector, not a guaranteed raw-wire cut length. The listed initial blank adds7mm for contact insertion, solder preparation and final dressing. Keep the destination end untrimmed until bench dressing is complete; then trim to fit the open route with a small relaxed bow. Cut-length excess used inside contacts/joints is not service slack. Do not stuff unused lengths under the PCB. Disconnect plugs before lifting the board for service.

| Named CAD wire | Routed length mm | Initial non-battery blank mm |
|---|---:|---:|
| J2_FACTORY_LEAD_1_MINIMUM_ROUTE |65.85|Preserve factory|
| J2_FACTORY_LEAD_2_MINIMUM_ROUTE |60.65|Preserve factory|
| J3_MIC_LEAD_1 |55.69|63|
| J3_MIC_LEAD_2 |60.50|68|
| J3_MIC_LEAD_3 |65.31|73|
| J3_MIC_LEAD_4 |72.95|80|
| J3_MIC_LEAD_5 |72.39|80|
| J3_SEL_GND_JUMPER |14.56|22|
| J10_SPEAKER_LEAD_1 |103.05|111|
| J10_SPEAKER_LEAD_2 |104.49|112|
| J9_PIN_1 |118.26|126|
| J9_PIN_2 |81.47|89|
| J9_PIN_3 |48.16|56|
| J9_PIN_4 |58.43|66|
| J9_PIN_5 |64.76|72|
| J9_RETURN_1 |60.22|68|
| J9_RETURN_2 |56.21|64|
| J9_RETURN_3 |28.03|36|
| J9_RETURN_4 |70.18|78|
| J8_LED_1 |98.44|106|
| J8_LED_2 |96.35|104|
| J8_LED_3 |101.58|109|
| J8_LED_4 |107.36|115|
| J8_FORMED_LED_PIN_1 |12.16|Form original lead; do not cut to this CAD number|
| J8_FORMED_LED_PIN_2 |12.31|Form original lead; do not cut to this CAD number|
| J8_FORMED_LED_PIN_3 |12.52|Form original lead; do not cut to this CAD number|
| J8_FORMED_LED_PIN_4 |12.79|Form original lead; do not cut to this CAD number|
| J5_FACTORY_COAX_150mm |150.00|Preserve factory|

The Adafruit-linked2014 pack drawing shows100mm bare leads; the current product describes a later taped sideways exit. The model therefore keeps the received assembly intact, shows minimum routes and reserves a separate centre slack bay. Do not remove protective tape to obtain length. Factory length/exit dressing is a first-article go/no-go check, not a claim that all100mm is free cable.

## Practical assembly envelopes

- Mic solder joints: individual maximumØ1.8x2.6mm; keep solder/insulation low and the bottom acoustic port open. The open keeper slot accepts the already-wired board and SEL jumper.
- Button junction: one insulated common-return splice, maximumØ3.3x12mm, in its named open central bay. The four switch returns connect here; none uses a case part or speaker lead as ground.
- Switch joints:Ø1.7mm envelopes at volume switches;Ø1.9mm at PTT/play. Leave no exposed conductor. Solder only the removable switches/cables, never modify the main PCB.
- LED joints: individualØ1.7x5mm envelopes. Form each supplied long LED lead once with a holding tool, at least3mm from the package; do not transmit the bending load into the lens. The model uses a straight stand-off before the bend.
- Battery slack bay: X-10..10,Y32..56,Z-19.3..-17.6 in assembly coordinates; it lies between the rear battery support plinths. Dress both factory wires naturally there, clear of the antenna cable and pouch; do not stack thick knots.
- Wire reservations: typically0.5–0.75mm radial allowance for thin signal wires;1mm around general battery runs, locally0.3mm normal allowance at the pouch exit. Coax reserves1mm lateral and0.3mm normal room at its rear plane. These are design budgets, not measured cable tolerances.
- Gentle loops and open access provide serviceability. Hold the separated halves before unplugging the battery; disconnect the board harnesses before lifting the PCB. A connector pigtail never removes the original plug height.

## Primary references

- [JST PH housings/contacts](https://www.jst-mfg.com/product/pdf/eng/ePH.pdf).
- [JST KR-D transverse-exit connector](https://www.jst-mfg.com/product/pdf/eng/eKRD.pdf).
- [Kingbright LED pin order and forming instructions](https://www.kingbrightusa.com/images/catalog/spec/wp154a4sureqbfzgw.pdf).
- [Adafruit2011 product](https://www.adafruit.com/product/2011) and [linked pack drawing](https://cdn-shop.adafruit.com/datasheets/LiIon2000mAh37V.pdf).
- [Taoglas antenna](https://www.taoglas.com/datasheets/FXUB63.07.0150C.pdf).