RFS 5085-3 Radio Frequency Vhf Duplexer

( Brand: Rfs ), ( Manufacturer Part Number: 5085-3 ), ( Type: Vhf Duplexer ), ( Color: Black ), ( Country Of Origin: United States )

Review RFS Radio Frequency Systems Vhf Duplexer Tested Working

The **RF Solutions 5085-3 VHF Duplexer** is a high-performance, compact, and versatile RF component designed to facilitate seamless communication in duplex applications across the Very High Frequency (VHF) spectrum, spanning from **136 MHz to 174 MHz**. Engineered with precision for both commercial and military-grade applications, this duplexer excels in environments where reliable signal isolation between transmit and receive paths is critical, such as in two-way radio systems, satellite communications, and test equipment. Its robust construction ensures minimal insertion loss and superior isolation, allowing for efficient power handling and minimal interference between the transmit and receive channels. The duplexer employs a **cavity-backed design**, which enhances its mechanical stability and thermal performance, making it ideal for operation in demanding conditions where temperature fluctuations or mechanical stress could otherwise degrade performance. With a **VSWR (Voltage Standing Wave Ratio) of 1.3:1 or better**, the 5085-3 guarantees optimal impedance matching, ensuring maximum power transfer and minimal signal reflection, which is essential for maintaining signal integrity in high-fidelity communication systems. Its **dual-band capability** allows for flexible deployment in applications requiring simultaneous operation across multiple frequency ranges, while its **low insertion loss (typically less than 0.5 dB)** ensures that signal strength remains robust throughout transmission and reception. Additionally, the duplexer is constructed with **high-quality materials**, including corrosion-resistant finishes and precision-machined components, which extend its operational lifespan and reliability in harsh environments. Whether integrated into a base station, mobile unit, or portable communication device, the RF Solutions 5085-3 delivers uncompromising performance, making it a trusted choice for engineers and system designers seeking a dependable solution for duplex RF applications.

The **RFS 5085-3** is a VHF duplexer designed for amateur radio and two-way communication applications, particularly for use with transceivers that require a separate receive and transmit antenna. Below is a detailed breakdown of its pros and cons, followed by a conclusion and recommendation.

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### **Pros of the RFS 5085-3 Duplexer**

1. **Frequency Range and Performance**

The duplexer covers the **144 148 MHz (2m band)** with a **30 dB isolation** between transmit and receive paths. This ensures minimal interference between the two signals, which is critical for clear communication. The low insertion loss (typically under 0.5 dB) maintains signal strength with minimal degradation.

2. **Durability and Build Quality**

The RFS 5085-3 is constructed with **high-quality materials**, including stainless steel and rugged connectors (usually UHF or SO-239). It is designed to withstand outdoor conditions, making it suitable for mobile or portable setups. The internal components are also well-shielded to prevent interference from external sources.

3. **Compact and Lightweight**

Compared to some other duplexers, the 5085-3 is relatively small and easy to install in tight spaces, such as in a vehicle or on a portable antenna system. Its lightweight design does not add significant weight to the antenna setup.

4. **Wide Bandwidth**

The duplexer supports the entire **2m band**, allowing flexibility for different modes (FM, SSB, digital) without needing multiple units. This makes it versatile for various amateur radio applications, including repeater systems, mobile operation, and portable use.

5. **Low Power Handling**

It can handle **up to 100 watts of RF power**, which is sufficient for most amateur radio transmitters. This makes it suitable for both low-power handheld radios and high-power mobile/portable setups.

6. **Easy Installation**

The duplexer comes with standard connectors (typically UHF or SO-239), which are common in amateur radio equipment. Installation is straightforward, requiring only basic soldering or direct connection to existing coaxial cables.

7. **Reliability and Longevity**

RFS (Radio Frequency Systems) is a well-known brand in the amateur radio community, and their products are generally reliable. The 5085-3 has a proven track record with minimal reported failures, suggesting good long-term performance.

8. **Cost-Effective for the Features Offered**

While not the cheapest duplexer on the market, it offers a good balance between performance and price. For the features it provides (isolation, bandwidth, power handling), it is competitively priced compared to alternatives like the **RFS 5085-2** or **RFS 5085-4**.

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### **Cons of the RFS 5085-3 Duplexer**

1. **Limited Frequency Range**

The duplexer is **exclusively for the 2m band (144 148 MHz)**. If you operate on other bands (e.g., 70 cm, 6m, or HF), you would need a separate duplexer for each band. This lack of multi-band capability may require additional investment if you use multiple bands.

2. **Connector Compatibility Issues**

While the connectors are standard, some users may find that the **UHF or SO-239 ports** do not match their existing equipment. This could require adapters or additional hardware, adding to the setup complexity.

3. **No Built-In SWR Protection**

The duplexer does not include built-in **SWR (Standing Wave Ratio) protection**, which means that if your antenna is mismatched, it could reflect excessive power back into the transmitter. This could potentially damage the transmitter if not monitored. Users must ensure proper antenna tuning and use an SWR meter.

4. **Sensitivity to Physical Damage**

While durable, the duplexer is not completely immune to physical damage. Rough handling, exposure to extreme temperatures, or moisture can affect performance. It is best stored in a dry environment when not in use.

5. **No Built-In Filtering for Harmonics**

The duplexer provides isolation between transmit and receive paths but does not inherently filter out harmonics (e.g., 2x or 3x the transmit frequency). Users may need additional filters if operating near other bands or sensitive receivers.

6. **Limited Customization**

The 5085-3 is a standard unit with fixed specifications. If you require custom impedance matching or specific connector types, you may need to modify it or source a different model.

7. **Potential for Signal Leakage in Poorly Shielded Environments**

While the shielding is generally good, in environments with strong electromagnetic interference (e.g., near power lines or other high-power transmitters), some signal leakage could occur. This is rare but worth considering for sensitive applications.

8. **No Warranty on DIY Modifications**

If you attempt to modify the duplexer (e.g., changing connectors or internal components), the manufacturer s warranty may not cover any resulting issues. It is best to leave modifications to professionals if needed.

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### **Conclusion**

The **RFS 5085-3** is a well-regarded duplexer for **2m band amateur radio applications**, offering excellent isolation, low insertion loss, and durability. It is an ideal choice for users who primarily operate on the 2m band and require a reliable, compact solution for separating transmit and receive signals. Its performance justifies the cost for most hobbyists and operators who need a high-quality duplexer without unnecessary complexity.

However, its **limited frequency range** and lack of built-in SWR protection or harmonic filtering may be drawbacks for users with more diverse needs. If you operate on multiple bands or require additional features, you may need to supplement it with other components.

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### **Recommendation**

- You **primarily use the 2m band** (144 148 MHz) for FM, SSB, or digital modes.

- You need **high isolation (30 dB) and low insertion loss** for clear communication.

- You require a **durable, compact, and reliable** duplexer for mobile, portable, or repeater applications.

- You are willing to **monitor SWR and use an external SWR meter** to protect your transmitter.

- You do not operate near other bands that could be affected by harmonics.

- You operate on **multiple bands** (e.g., 70 cm, 6m, or HF) and need a multi-band duplexer.

- You require **built-in SWR protection or harmonic filtering**, which may necessitate additional components.

- You prefer a **lower-cost option** and are willing to compromise slightly on performance (e.g., the RFS 5085-2 has slightly lower isolation at 25 dB).

- You need **custom connectors or impedance matching**, which may require modifications or a different model.

For most **2m band enthusiasts**, the RFS 5085-3 is a **strong and practical choice** that delivers excellent performance for its intended use. Pair it with a good antenna and SWR meter to ensure optimal operation.

Details:

From a smoke-free home. These charges are not covered in your shipping costs. RFS Radio Frequency Systems 5085-3 VHF Duplexer Tested Working. Listing is for duplexer and mounting screws shown ONLY, no other parts are included.

Please view all photos. Ask any questions prior to purchasing.

part #: 50853 price

• $399.99

specifications hamamateuradio:

• brand: Rfs
• mpn: 5085-3
• type: Vhf Duplexer
• color: Black
• country of origin: United States

general hamamateuradio:

• Radio Communication > Ham, Amateur Radio > Ham Radio Transceivers
• condition: Used

shipping hamamateuradio:

• carrier: USPS, UPS
• service: USPS Ground Advantage, UPS Ground Saver, USPS Priority Mail, USPS Priority Mail Express
• cost: $27.25
• type: Calculated
• class: Standard, Economy, Expedited
• transit: 4-8 Days

payments hamamateuradio:

• other
• wallet: Apple-pay
• credit card: Visa

returns hamamateuradio:

• paid by: Buyer
• method: Money back
• time: 30 Days
• policy: Returns Accepted

offer hamamateuradio:

• quantity: 1
• availability: In Stock
• sold: 0
• options: Ship-to-home
• started: May 25, 2026

seller hamamateuradio:

• rating: 100.0%
• # reviews: 6342
• city: Pleasant Valley, New York

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