[Scan-DC] WSMX999 STA America 250th July 4th on The Mall is On The Air

[Andrew Clegg]

The emission designator for each listed channel is 7K60FXE. Gemini’s description of this emission is below.

According to radioreference, MOTOTRBO is decodable by some current digital scanner models, assuming the operator doesn’t add encryption.

The licensee, Bearcom, appears to be a radio contractor. I wonder who they are deploying this system for. Will it be trunked? Encrypted?

If I had stayed in DC for the weekend I would have given it a listen.

Happy July 4th holiday!

73,
Andy
W4JE

*****

The emission code **7K60FXE** corresponds to a **2-slot Digital Mobile Radio (DMR) TDMA digital voice signal**, most commonly associated with commercial systems like Motorola's **MOTOTRBO**.
Breaking down the ITU emission designator system reveals exactly how this signal is constructed:
### 1. Necessary Bandwidth (7K60)
 * **7K60**: Indicates a necessary bandwidth of **7.60 kHz**.
 * This is designed to fit comfortably inside a standard narrow-band 12.5 kHz channel allocation.
### 2. First Symbol: Type of Modulation (F)
 * **F**: Represents **Frequency Modulation (FM)**.
 * In the context of DMR, the raw digital data modulates the carrier frequency using 4-level Frequency Shift Keying (4FSK).
### 3. Second Symbol: Nature of the Modulating Signal (X)
 * **X**: Cases not otherwise covered.
 * In this specific context, it represents **Time-Division Multiple Access (TDMA)**. DMR splits a single 12.5 kHz channel into two independent alternating time slots, allowing two distinct conversations or data streams to share the same frequency simultaneously.
### 4. Third Symbol: Type of Transmitted Information (E)
 * **E**: **Telephony / Voice**.
 * This signifies that the payload being carried over the digital stream is digitized voice communications.
> **Note on Variations:** You will often see this alongside **7K60FXD**, where the **D** at the end signifies data transmission (such as GPS coordinates, text messages, or telemetry) rather than voice.
>


On Jul 2, 2026, at 3:57 AM, Andrew Clegg via Scan-DC <scan-dc at mailman.qth.net> wrote:


Here’s a link to the license as listed on radioreference.


https://www.radioreference.com/db/fcc/callsign/WSMX999


On Jul 2, 2026, at 1:40 AM, Freq Finder via Scan-DC <scan-dc at mailman.qth.net> wrote:


______________________________________________________________
Scan-DC mailing list
Home: http://mailman.qth.net/mailman/listinfo/scan-dc
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Scan-DC at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html