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July 2025
PXI-5691
PXI-5691, 2-Channel, 8 GHz, SMA Female Connectors, PXI RF Amplifier
Actual item may vary if no part number is provided on quote request.
✔ 2 Year Warranty Included
✔ Free Domestic Ground Shipping
✔ NIST Calibration Available
Andrew Gar**** Verified Buyer
" Amazing to work with and had my order within 1 week after purchasing with all NI certs and data that were needed. "
March 2025
Said Sai**** Verified Buyer
" Competent contact for highly specialized components. The support team is very knowledgeable. Many thanks for the help and the fast shipping! "
January 2025
Bob C**** Verified Buyer
" Jason was able to get our emergency situation taken care of quickly and professionally. "
May 2025
Gregg Flecki**** Verified Buyer
" Great service and great products. This is my 2nd time using Apex Waves, truly impressed. "
January 2025
Carol Zimme**** Verified Buyer
" Very responsive and helpful, competitive pricing. Good source! "
July 2025
Andrew Gar**** Verified Buyer
" Amazing to work with and had my order within 1 week after purchasing with all NI certs and data that were needed. "
March 2025
Said Sai**** Verified Buyer
" Competent contact for highly specialized components. The support team is very knowledgeable. Many thanks for the help and the fast shipping! "
January 2025
Bob C**** Verified Buyer
" Jason was able to get our emergency situation taken care of quickly and professionally. "
May 2025
Gregg Flecki**** Verified Buyer
" Great service and great products. This is my 2nd time using Apex Waves, truly impressed. "
January 2025
National Instruments PXI-5691 PXI RF Amplifier
The National Instruments PXI-5691 (Part Numbers: 781035-01, 195812F-01L) is a 2-channel, 8 GHz, programmable PXI RF amplifier. It features Channel 0 as a fixed-gain amplifier and Channel 1 as a programmable-gain amplifier with a direct bypass option, all housed in a single-slot 3U PXI module. This module has a low noise figure and adjustable gain, optimizing the sensitivity and dynamic range of compatible PXI RF vector signal analyzers. The NI PXI-5691 can also bypass its gain programmatically through switching to a direct path. This functionality enhances monitoring and testing performance of compatible PXI RF Vector Signal Analyzers by providing the user with the capability to shift the dynamic range to easily and quickly monitor extremely weak or strong signals.
Channel 0 (CH 0) of this module offers ±0.9 dB level calibration accuracy, +30 dBm typical absolute maximum input power, +20 dBm maximum reverse power (without damage), +25 dBm maximum output power, and ±10 V typical DC voltage at the input. Channel 1 (CH 1) offers +31.5 dB gain range, +0.5 dB gain step size, +4 µs maximum level settling time, ±0.9 dB level calibration accuracy, and +30 dBm absolute maximum input power while operating in typical conditions. CH 1 also includes a direct path, which bypasses the amplifier circuitry and passes signals directly through with minimal attenuation. The device has a maximum power of 2.1 W at 3.3 Vdc, 6.9 W at 5 Vdc, 2.9 W at 12 Vdc, and 0.34 W at -12 Vdc.
The PXI-5691 operates with the NI driver software, which is compatible with software packages/application development environments such as LabVIEW, C, or LabWindows/CVI. The device can be configured using the Measurement & Automation Explorer (MAX) tool.
The NI PXI-5691 features 4 SMA female front panel connectors for all the channel inputs and outputs. These connectors are designed to operate at 50 Ω impedance, with AC coupling for all paths except for Channel 1’s direct path, which is DC coupled. This RF amplifier weighs 9.2 oz. and measures 21.6 × 2.0 × 13.0 cm in physical dimensions. The PXI-5691 RF amplifier is designed to operate within a frequency range of 50 MHz to 8.0 GHz. It has a recommended operating temperature range of 0 °C to 55 °C, a storage temperature range of -40 °C to 70 °C, a warm-up time of 10 minutes, and a recommended calibration interval of 1 year.
The PXI-5691 is no longer available direct from National Instruments (NI), but the PXI RF amplifier will remain available in perpetuity with Apex Waves for either purchase or repair services!
| Model | PXI-5691 |
|---|---|
| Part Number | 781035-01, 195812F-01L |
| Manufacturer | National Instruments |
| Type | PXI RF Amplifier |
| Channels | 2 |
| Frequency Range | 50 MHz to 8.0 GHz |
| Maximum Output Power | +25 dBm |
| Bus Connector | PXI (Standard PXI Peripheral Slot, not PXIe or Hybrid) |
| Gain Range (CH 1) | +31.5 dB, with a 0.5 dB Step Size |
| Front Panel Connector Type | SMA Female |
| Front Panel Connector Coupling | AC |
| DC Voltage at Input | ±10 V, Typically |
| Calibration Interval | 1 Year |
| Operating Temp Range | 0 °C to 55 °C |
| Storage Temp Range | -40 °C to 70 °C |
| Dimensions | 8.5 x 0.8 x 5.1 in. (21.6 cm × 2.0 cm × 13.0 cm) |
| Price | Request a Quote |
Associated part numbers for PXI-5691:
National Instruments PXI-5691 Frequently Asked Questions
Question: What is the input amplitude of the PXI-5691?
Answer: The input amplitude of the RF amplifier is +30 dBm maximum.
Question: What is the gain of the two channels on the NI PXI-5691?
Answer: Channel 0 has a fixed gain, and Channel 1 has a programmable gain.
Question: How long should the PXI RF amplifier warm up before use?
Answer: Before operation, the PXI-5691 should warm up for at least 10 minutes.
Question: What is the DC voltage at input for the PXI-5691?
Answer: The DC voltage at the input is ±10 V (typical), applicable to Channel 1's Direct Path.
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