1. Introduction
This manual provides detailed instructions for the proper use and maintenance of your EPSILON EPS-HS-K headset. This headset is designed for seamless integration with compatible Kenwood low-power walkie talkies, offering clear communication and hands-free operation capabilities.
Please read this manual thoroughly before using the product to ensure optimal performance and longevity.
2. Product Overview
The EPSILON EPS-HS-K is a wired headset featuring a comfortable over-ear design and a flexible microphone. It is engineered for professional communication environments where clear audio and reliable operation are essential.
2.1 Key Features
- Noise-Reducing Microphone: A 5.9-inch (15 cm) microphone designed to minimize wind and external noise interference.
- Large PTT Switch: A 3 cm Push-To-Talk (PTT) switch for easy and reliable activation.
- Soft Sponge Earpiece: Provides comfort during extended use.
- Retractable Cable: The main cable from the walkie talkie to the switch extends from approximately 55 cm to 200 cm. The cable from the switch to the ear pad is 30 cm.
- VOX Compatibility: Supports Voice Operated Exchange for hands-free communication, allowing transmission without pressing the PTT button. (Requires VOX function on the connected walkie talkie and proper sensitivity adjustment.)
2.2 Components
The EPS-HS-K headset includes the following main components:
- Headband with integrated earpiece
- Flexible boom microphone with foam cover
- In-line Push-To-Talk (PTT) switch
- Coiled connecting cable with two-pin connector for walkie talkie

Figure 1: EPSILON EPS-HS-K Headset showing the PTT switch and coiled cable. This image illustrates the overall design and key functional parts of the headset, including the microphone and earpiece.

Figure 2: The EPSILON EPS-HS-K Headset demonstrated on a mannequin head, highlighting its ambidextrous design for wearing on either the left or right ear. This shows how the headset can be adjusted for user comfort.
3. Setup
- Connect to Walkie Talkie: Locate the two-pin audio jack on your compatible Kenwood walkie talkie. Insert the headset's two-pin connector firmly into the walkie talkie's audio port. Ensure both pins are fully seated to establish a secure connection.
- Position Headset: Place the earpiece comfortably over your ear. The headset is designed to be worn on either the left or right side. Adjust the headband for a snug fit.
- Adjust Microphone: Position the flexible boom microphone approximately 1-2 inches (2.5-5 cm) from your mouth. Ensure the foam cover is securely on the microphone to reduce breath noise.
- Secure PTT Switch: Clip the in-line PTT switch to your clothing in an easily accessible location, such as a collar or pocket.
4. Operating Instructions
4.1 Basic Communication (PTT Mode)
- To transmit, press and hold the large PTT switch.
- Speak clearly into the microphone.
- Release the PTT switch to stop transmitting and return to receive mode.
4.2 VOX Operation (Hands-Free)
The EPS-HS-K headset is VOX compatible. To use the VOX function, your Kenwood walkie talkie must also support VOX and have it enabled.
- Enable the VOX function on your Kenwood walkie talkie according to its specific user manual.
- Adjust the VOX sensitivity level on your walkie talkie. Start with a medium setting and adjust as needed. If the VOX activates too easily (e.g., from background noise), decrease the sensitivity. If it doesn't activate when you speak, increase the sensitivity.
- Once VOX is properly configured, you can transmit by speaking into the microphone without pressing the PTT button. Transmission will automatically cease when you stop speaking.
Note: Optimal VOX performance depends on the walkie talkie's settings and environmental noise levels.
5. Maintenance
- Cleaning: Wipe the headset and cables with a soft, damp cloth. Do not use harsh chemicals or abrasive cleaners.
- Storage: Store the headset in a dry, cool place away from direct sunlight and extreme temperatures. Avoid tangling the cables.
- Cable Care: Do not pull on the cables forcefully. Always grasp the connector when plugging or unplugging the headset.
- Microphone Foam: Ensure the microphone foam cover is clean and intact to maintain optimal audio quality and reduce wind noise. Replace if damaged.
6. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No audio from earpiece. |
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| Cannot transmit (PTT not working). |
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| VOX not activating or activating too easily. |
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| Poor audio quality (static, muffled sound). |
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7. Specifications
| Model Name: | EPS-HS-K |
| Brand: | EPSILON |
| Connectivity Technology: | Wired |
| Ear Placement: | On Ear |
| Form Factor: | Over Ear |
| Microphone Length: | 5.9 inches (15 cm) |
| PTT Switch Size: | 3 cm |
| Cable Length (Walkie Talkie to Switch): | Approx. 55-200 cm (retractable) |
| Cable Length (Switch to Ear Pad): | 11.8 inches (30 cm) |
| Item Weight: | 2.82 ounces (80 grams) |
| Product Dimensions: | 9.84 x 7.87 x 1.97 inches (25 x 20 x 5 cm) |
| Included Components: | Headset (Earphone) |
8. Compatible Models
The EPSILON EPS-HS-K headset is compatible with the following Kenwood walkie talkie models:
- UBZ-LP20
- UBZ-LP27
- UBZ-LJ20
- UBZ-LK20
- UBZ-LM20
- UBZ-EA20R
- UBZ-BM20R
- UBZ-S27/S20
- UBZ-BG20R
- UBZ-BH47FR
- UBZ-S700
- UTB-10
Note: Compatibility with other models is not guaranteed. Always verify your walkie talkie's connector type before purchase.
9. Warranty and Support
For warranty information or technical support, please refer to the documentation provided with your purchase or contact your retailer. Keep your proof of purchase for warranty claims.





