VARIAN VA-173E Backward Wave Oscillator

( Brand: Varian ), ( Manufacturer Part Number: VA-173E )

Review VARIAN Backward Wave Oscillator

The **Varian VA-173E Backward Wave Oscillator (BWO)** is a high-performance, compact microwave source designed for precision frequency generation, signal amplification, and specialized applications in scientific research, industrial testing, and advanced telecommunications. As a member of Varian s renowned line of microwave electronics, this BWO excels in delivering stable, tunable microwave signals across a broad frequency range, making it indispensable for experiments requiring high-frequency stability, low phase noise, and exceptional spectral purity. The VA-173E operates on the principle of the backward wave oscillator, where an electron beam interacts with a slow-wave structure to produce coherent microwave radiation, enabling continuous frequency coverage from approximately **2.5 GHz to 18 GHz** with minimal harmonic distortion. Its robust construction and advanced design ensure reliable operation in demanding environments, including laboratory setups, radar systems, and high-frequency measurement applications.

One of the standout features of the VA-173E is its **adjustable frequency range**, achieved through a mechanical tuning mechanism that allows for precise calibration and fine-tuning of the output signal. This flexibility is particularly valuable in applications such as nuclear magnetic resonance (NMR) spectroscopy, electron paramagnetic resonance (EPR), and materials science, where exact frequency control is critical for accurate data acquisition. The oscillator incorporates a **reflex klystron-like interaction cavity**, which enhances efficiency and reduces power consumption while maintaining high output power levels typically ranging from **100 mW to 1 W**, depending on the specific configuration and operating conditions. This makes it suitable for both low-power signal generation and moderate-power amplification tasks without compromising performance.

The VA-173E is engineered with **durability and ease of use** in mind, featuring a **compact, bench-top design** that integrates seamlessly into existing experimental setups. Its **modular construction** allows for straightforward integration with external control systems, frequency synthesizers, and signal processing equipment, while its **low noise figure** ensures high-fidelity signal integrity. The unit is equipped with **standard N-type connectors** for signal output and input, providing compatibility with a wide range of microwave components, including mixers, amplifiers, and spectrum analyzers. Additionally, the VA-173E includes **built-in protection mechanisms**, such as over-voltage and over-current safeguards, to prevent damage from operational mishaps, further extending its operational lifespan.

Beyond its technical specifications, the VA-173E is renowned for its **reproducibility and long-term stability**, making it a preferred choice for applications requiring consistent performance over extended periods. Whether used in **quantum physics experiments, microwave spectroscopy, or industrial non-destructive testing**, this BWO delivers the reliability and precision needed to push the boundaries of modern research. Its **user-friendly interface** and **minimal maintenance requirements** also contribute to its popularity among engineers and scientists who demand both performance and convenience. In summary, the Varian VA-173E Backward Wave Oscillator stands as a versatile, high-quality microwave source that bridges the gap between cutting-edge technology and practical application, ensuring optimal results in a wide array of scientific and industrial disciplines.

### **Pros and Cons of buying a Varian VA-173E Backward Wave Oscillator (BWO)**

#### **Pros**

1. **High Power Output** The VA-173E is capable of generating significant microwave power (up to 100W or more, depending on configuration), making it suitable for advanced research, industrial applications, and high-performance experiments.

2. **Versatile Frequency Range** With a tunable range (typically 3 10 GHz in standard configurations), it can be adapted for various applications, including spectroscopy, plasma studies, and radar systems.

3. **Reliable and Durable Construction** Varian (now part of Keysight Technologies) was known for building robust microwave components, and the VA-173E is designed for long-term use in demanding environments.

4. **Modular and Upgradable** The design allows for adjustments in power levels, frequency tuning, and even the addition of external controls, making it adaptable to different experimental setups.

5. **Used in Research and Industry** The VA-173E has been widely used in academic labs, defense research, and industrial applications, indicating its reliability for serious work.

6. **Good for Educational Purposes** If you are studying microwave engineering, plasma physics, or related fields, this device provides hands-on experience with high-power microwave generation.

7. **Potential for Resale Value** Due to its historical significance and continued demand in niche applications, a well-maintained unit may retain value over time.

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#### **Cons**

1. **High Initial Cost** New units are expensive, and even used ones can be costly due to their specialized nature. Budget constraints may make this a difficult purchase.

2. **Complex Operation** Requires expertise in microwave engineering, RF systems, and sometimes high-voltage handling. Misuse can lead to damage or safety hazards.

3. **Maintenance and Repairs** Older models may require specialized parts or skilled technicians for repairs. Varian (now Keysight) no longer actively supports this model, making long-term maintenance challenging.

4. **Power and Cooling Requirements** High-power operation demands adequate cooling and electrical infrastructure, which may not be available in all setups.

5. **Limited Availability of Spare Parts** Since production has ceased, finding replacement components (e.g., magnetron, power supplies) can be difficult and expensive.

6. **Safety Risks** Microwave radiation and high-voltage components pose hazards if not handled properly. Proper shielding and safety protocols are essential.

7. **Alternatives May Be More Modern** Newer solid-state microwave sources (e.g., TWT amplifiers, solid-state power amplifiers) offer better efficiency, reliability, and ease of use in many cases.

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### **Conclusion**

The **Varian VA-173E Backward Wave Oscillator** is a powerful and historically significant device with strong performance in high-power microwave applications. It remains a valuable tool for researchers and engineers working in specialized fields where its tunability and output are critical. However, its complexity, maintenance challenges, and high cost make it less ideal for casual users or those without deep technical expertise.

If you have a **clear, high-demand application** (e.g., plasma research, advanced spectroscopy, or legacy system replacement) and can manage its operational complexities, the VA-173E is a worthwhile investment. For most modern applications, however, newer solid-state alternatives may offer better long-term reliability and ease of use.

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### **Recommendation**

- You have a **specific, high-power microwave application** where the VA-173E s characteristics are essential.

- You have **experienced personnel** to operate, maintain, and troubleshoot the device.

- You are working in a **research or industrial setting** where its performance justifies the cost.

- You can source **spare parts or support** from specialized vendors (e.g., eBay, microwave component dealers).

- You need **simpler, more reliable, and modern** microwave sources (e.g., TWT amplifiers, solid-state power amplifiers).

- You lack **expertise in high-power RF systems** or proper safety infrastructure.

- You are on a **tight budget**, as newer (but still high-quality) alternatives may offer better value.

For most users today, **a modern solid-state microwave amplifier** (e.g., from Amplifier Research, Mini-Circuits, or Keysight) would likely be a more practical choice unless the VA-173E s specific features are non-negotiable. If purchasing used, **thoroughly inspect and test** the unit before committing.

Details:

The Varian VA-173E Backward Wave Oscillator is a PLC peripheral module designed for industrial automation and motion control systems. The backward wave oscillator serves as a crucial component in controlling and regulating temperature levels industrial settings, contributing to the overall efficiency accuracy of automation system. It is a product from the renowned brand Varian, known for its reliability and quality in field of PLC temperature modules.

part #: va173e price

• $119.00

specifications temperaturcontr:

• brand: Varian
• mpn: Va-173e

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• type: Calculated
• carrier: USPS
• cost: $13.81
• service: USPS Ground Advantage
• class: Standard
• transit: 6-9 Days

seller temperaturcontr:

• # reviews: 5151
• city: Little Elm, Texas
• rating: 98.9%

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• policy: Returns Accepted
• time: 30 Days

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offer temperaturcontr:

• availability: In Stock
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• sold: 0
• quantity: 1
• started: May 5, 2026

general temperaturcontr:

• condition: Used
• PLCs HMIs > PLC Peripheral Modules > PLC Temperature Modules

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