SDS100 GPS receiver

Uniden SDS100 GPS Guide (2025)

As of 2025, the Uniden BC-SGPS kit remains the only officially supported and readily available GPS solution for the SDS100. Retailing at approximately $100, it offers a complete and reliable setup for accurate, self-updating location services.

To reduce confusion from outdated forum posts and fragmented information, this guide consolidates the most up-to-date details on using GPS functionality with the Uniden SDS100 scanner. It is culled from numerous forum posts, notes, and personal research. While too numerous to list individually, a big Thank you to everyone who contributed to making this information available.

Using Location Services on the SDS100

Avoid relying on Auto Locate. The Auto Locate feature scans active frequencies in your environment and attempts to determine your location by matching them against the internal database. Reports indicate that this process can take 7–10 minutes and is often inaccurate.
Enter your ZIP code. The simplest method—without additional hardware—is to manually enter your ZIP code (North America only). The scanner will assume your location is the geographic center of that ZIP code. While this is generally sufficient, you must manually update the ZIP code when you change locations.
Use a GPS receiver. Attaching a GPS receiver provides the most accurate and convenient solution, as the scanner will update its location automatically.

Choosing a GPS Receiver

Several options exist for adding GPS to the SDS100. These range from official Uniden products, to third-party receivers, to DIY external and internal modifications. It is important to note that, as of 2025, many components—official and unofficial—are no longer available new.

Official Uniden Products

Uniden BC-SGPS Serial GPS Receiver Includes: cigarette-lighter power cord, black power adapter unit, square GPS module (RJ14 connection at TTL power level), and multiple serial (RS232) cables terminating in USB Mini for use with scanners such as the SDS100. Price: $99.99 (Uniden website). Operates at 9600 bps. Status: Officially available and currently supported. Replaces the discontinued BC-GPSK.
Uniden CB-GPSK Includes only the GPS receiver module and RJ14 cable. For SDS100 use, it is not practical without the BC-SGPS power adapter and serial cables. For SDS200, the RJ14 connection works directly without an adapter.
Uniden BC-GPSK Serial GPS Receiver (discontinued) A round GPS “puck” with a PS/2 mini-DIN connector. To connect to the SDS100, requires the additional Uniden BC-UTGC GPS USB Cable ($14.99, still available from Uniden). Operates at 4800 bps.

Third-Party GPS Options

The discontinued Uniden BC-GPSK was functionally identical to:

Globsat BR-355S4 Confirmed compatible with SDS100 (requires BC-UTGC cable). Discontinued.

Globsat BR-355N Successor to the BR-355S4. Confirmed compatible, but as of 2025, no longer widely available, though not officially marked as end-of-life.

Note: Other Globsat puck models use USB connectors with FTDI chips instead of PS/2 mini-DIN. These may still be used in DIY modifications, but not with the standard BC-UTGC cable.

Summary:

It is not feasible in 2025 to purchase a new BC-GPSK, BR-355S4, or BR-355N. If pursuing the “round puck + splitter cable” option, a used puck with a new BC-UTGC cable is your best option. Otherwise, the Uniden BC-SGPS kit is the recommended solution, offering full support and compatibility with modern Uniden scanners.

Unofficial Modifications

Two categories of modifications exist:

External Mods

Involve wiring a GPS puck directly to the scanner and a separate power source, or using a battery-powered GPS unit.
Some pucks lack PS/2 mini-DIN connectors, requiring cable modifications or custom-built splitters.
The SDS100 accepts GPS input through its Mini-USB port but does not provide power through USB.
Notably, GPS data must be routed to the ID pin of the Mini-USB connector rather than the standard data pins (as reported by user jonwienke).
Any GPS transmitting standard NMEA sentences at a supported baud rate should theoretically function if correctly wired.

Internal Mods

Involve installing a GPS chip inside the scanner’s housing, connected to both the power system and GPS input pin.
This voids the device warranty.
Most guides are now outdated, as the required components are generally unavailable. It does not seem that any services offering professional installation still exist in 2025.

Product Summary

Uniden BC-SGPS – Complete GPS kit for multiple Uniden scanners. Includes adapter unit, cables, and square GPS module. Uses 9600 bps baud rate. Retail ~$100. Available.
Uniden CB-GPSK – GPS module + RJ14 cable. Useful only as replacement parts, or for SDS200. Retail ~$50. Available.
Uniden BC-GPSK – Discontinued round GPS puck, uses baud rate of 4800 bps. Requires BC-UTGC cable.
Uniden BC-UTGC – Splitter cable for PS/2 mini-DIN GPS pucks. Still available (~$15).
Globsat BR-355S4 – Third-party puck, discontinued. Functionally equivalent to BC-GPSK.
Globsat BR-355N – Replacement for BR-355S4, previously ~$45. Not readily available in 2025.

Setting Up GPS

Navigate to: Menu > Set Your Location > Set Up GPS.

Select location format (affects Latitude and Longitude display fields):

DMS: DDD*MM’SS.ss
Degree: DDD.dddddd

Configure serial port baud rate:

BC-GPSK / Globsat pucks – 4800 bps
BC-SGPS kit – 9600 bps
(Most scanners default to 4800 bps; must be corrected for BC-SGPS).

Optional: Enable GPS indicators in the display:

GPS icon shows active connection to GPS (regardless of GPS fix).
Latitude/longitude fields will update as you travel.
If no GPS fix is obtained, the latitude field displays “NO GPS.”

Programming With GPS

Full Database Scanning – Location is automatically applied.

Favorites List Scanning – To enable location-based control:

Enable Location Control for the favorites list is enabled.
Ensure that location data is programmed for each site and department.

Note: Location-based scanning only functions if every relevant Department/Site includes location data.