How to Add GPS to the Uniden SDS100
What Is Location-Based Scanning and Why Do You Want It?
Location-Based Scanning is one of the most powerful features of the SDS100. When a GPS receiver is connected, the scanner reads your real-time GPS coordinates and automatically activates the correct systems, sites, and talkgroups from the RadioReference database for your current location.
In practical terms, this means:
- Driving between counties or jurisdictions? The scanner automatically changes to the local emergency services as you cross boundaries — no manual adjustments needed.
- Road trips and travel: You're always hearing the right local channels wherever you go, as long as you've loaded the HPDB database via Sentinel.
- Better signal acquisition: LBS locks your scanner onto the correct sites for your location, which means stronger signals and better trunked system decode — especially on large multi-site P25 systems.
The Uniden BC-SGPS: Official GPS for the SDS100
The Uniden BC-SGPS is the only GPS receiver specifically designed and confirmed to work directly with the SDS100. It outputs a TTL-level NMEA 0183 serial signal that the SDS100 reads on Pin 2 of its USB Mini-B port — a proprietary connection unique to Uniden's scanner GPS interface.
| Specification | Details |
|---|---|
| Compatibility | SDS100, SDS200, BCD436HP, BCD536HP, HomePatrol-1/2 |
| Connection | Proprietary Uniden USB Mini-B cable (TTL serial on ID pin) |
| Signal Protocol | NMEA 0183 at TTL voltage levels (3.3V) |
| Mount Style | Magnetic base puck, dash/windshield mountable |
| Required Setup | Enable GPS in SDS100 menu after connecting |
| Price | ~$45–$70 (check current availability) |
✅ Pros
- Official Uniden product — guaranteed compatibility
- Plug-and-play, no drivers or PC needed
- Enables full Location-Based Scanning
- Magnetic mount base for easy dash placement
- Works with all major Uniden digitals (SDS100, SDS200, BCD436HP, BCD536HP)
⚠️ Cons
- Sometimes out of stock — check availability
- Proprietary connection (not a standard USB data cable)
- Occupies the SDS100's USB Mini-B port while in use
What About Other GPS Receivers?
A common question is whether something like the GlobalSat BU-353S4 (a popular USB GPS puck) will work with the SDS100. The answer requires some explanation:
The BU-353S4 does work great in a different setup: if you run PC-based scanner control software (like ProScan or ARC536) on a laptop alongside your scanner, the computer reads the BU-353S4 via USB as a standard virtual COM port GPS, and the software can use that location data. But that's a PC-based workflow — not a direct scanner GPS connection.
GlobalSat BU-353S4 — For PC-Based Scanner Software
| Chipset | SiRF Star IV |
| Interface | USB (creates virtual COM port on Windows) |
| Position Accuracy | ~2.5m CEP (with WAAS/SBAS) |
| Update Rate | 1 Hz |
| Channels | 48 |
| Cold Start | ~35 seconds typical |
| Hot Start | ~1 second |
| Compatible With | Windows PC via USB (ProScan, ARC536, etc.) |
| Direct SDS100 Use | ❌ Not compatible (requires host PC) |
If you're running scanner software on a Windows laptop connected to your SDS100, the BU-353S4 is a well-proven, affordable GPS puck that works reliably for this use case. Available on eBay from multiple sellers.
Find GlobalSat BU-353S4 on eBay →Bottom line: If you want GPS working directly on the SDS100 without a laptop involved, the BC-SGPS is the right choice. If you're running PC scanner software on a laptop and want an inexpensive USB GPS puck for it, the BU-353S4 is a good option.
How to Set Up the BC-SGPS on the SDS100
- Connect the BC-SGPS to the SDS100's USB Mini-B port using the included cable.
- Power everything on. Place the GPS puck where it has a clear view of the sky (dash, window ledge).
- Enable GPS on the scanner: MENU → Settings → GPS → On.
- Wait for GPS fix. First fix (cold start) can take 30–60 seconds outdoors. Subsequent fixes are faster.
- Confirm LBS is active: The scanner display will show location data and automatically load channels for your current area if you have the HPDB loaded via Sentinel.
You need the RadioReference HPDB (Hometown Database) loaded on your microSD card via Sentinel for Location-Based Scanning to actually activate channels. See the Sentinel programming guide for how to do this.
Frequently Asked Questions
Does the SDS100 have built-in GPS?
No. The SDS100 does not have a built-in GPS receiver. An external GPS is required for Location-Based Scanning. The official option is the Uniden BC-SGPS. If you want built-in GPS without any external hardware, the newer Uniden SDS150 has GPS built in from the factory.
Will the GlobalSat BU-353S4 work with the SDS100?
Not as a direct GPS connection. The BU-353S4 is a USB device that requires a host computer — it cannot be plugged directly into the SDS100 and used as a GPS source. The SDS100's GPS interface is a TTL-level serial signal on its USB port's ID pin, not standard USB. The only plug-and-play GPS for the SDS100 is the Uniden BC-SGPS.
Do I need GPS to use the SDS100?
No. GPS is optional. Without GPS, you can manually set your location by ZIP code in the SDS100 settings. Location-Based Scanning just automates this as you move. GPS is most useful when driving, traveling, or moving between scanning areas.
What does the SDS150 do differently for GPS?
The Uniden SDS150 has GPS built in — no external puck needed. If GPS is important to you and you haven't bought a scanner yet, the SDS150's built-in GPS (plus Bluetooth and U/AWARE app) may justify the higher price. For existing SDS100 owners, the BC-SGPS gets you the same LBS capability.