The network analyzer is missing the main HDD which initially prevents it from being tested. An image from a donor E5701C instrument is used to boot the unit and gain access to the instrument firmware. The unit shows an inaccurate S11 with an open Port 1 while S22 shows a perfect reflection. This indicates a potential problem with the Port 1 T/R module. Teardown of the module reveals catastrophic damage to the resistive front-end coupler which has been mostly likely caused by a large RF input power incident. After cleaning the PCB area, a replacement coupler is constructed. The repaired unit is checked for full self-test and used to measure a YIG tuneable filter.
You can may check the Andostar microscope lineup here. (Direct Link / Not-tracked)
More information about Wheatstone Bridge can be found here.
In this episode Shahriar repairs a Noise-XT 2MHz – 7GHz Ultra-Low Phase-Noise Clock Synthesizer. The instrument’s history indicates that it has suffered a fall from a work table. After a lot of difficulty, the instrument control software was found so that the unit can be tested.
Initial tests reveal that a very small output is present, however nearly 40dB below the desired value. The unit teardown shows an architecture based on dual Analog Devices DDS 14-bits DACs in conjunction with a Z-COMM VCO and a series of dividers & frequency multipliers. A detailed analysis of the unit is presented.
RF and analog measurements indicate that the RF connector is not making adequate contact with the final trace of the RF output. This explains the low output power. This problem is resolved by replacing the SMA connector entirely. The device output power, frequency accuracy, stability as well as cross-correlation phase-noise measurements are presented.
In this episode Shahriar reviews the top-of-the-line Tektronix 6-Series Oscilloscope. This 4-channel instrument offers 8-GHz of bandwidth at 25GS/s on all channel independently. Tektronix has made great strides in offering low-noise front-end custom ASICs combined with hardware digital down-conversion built into the core of the 6-Series. This enables advanced triggering across in both time and frequency domains as well as multi-domain correlated measurements.
This review is organized as follows:
00:06 – Introductions
01:42 – Instrument design, front and back panels
03:34 – Full acquisition board teardown, analysis and architecture
18:11 – PLL Experiment: Spectrum View, advanced triggering, PLL characterization and debugging
38:33 – Backplane Communication: Jitter analysis, eye diagrams, jitter composition, cross-talk
49:24 – Concluding remarks
In this episode Shahriar reviews the long awaited Signal HoundSM200C/B Real-Time 100kHz – 20GHz Real-Time Spectrum Analyzer:
The SM200C is a high-performance spectrum analyzer and monitoring receiver with a 10 Gigabit Ethernet SFP+ port, enabling the SM200C to communicate with a PC over long distances using a fiber optic cable. Designed for remotely-located accurate RF data analysis at the lowest cost possible, the SM200C features:
160 MHz instantaneous bandwidth I/Q streaming over 10GbE
SFP+ port for fast, long-distance communication with a PC using an optic cable
Device control and data transfer occurs via SFP+ connection, not USB
Tunes from 100 kHz to 20 GHz
Sweeps at 1 THz/sec at 30 kHz RBW
110 dB of dynamic range
Ultra-low phase noise
GPIO port antenna switching
The SM200B offers a USB 3.0 PC interface with 40MHz of instantaneous I/Q streaming. Furthermore, the SM200B includes a full 2-second of internal memory at 160MHz of capture bandwidth which an be accessed through the API.
The review is organized as follows:
00:00 – Introduction
00:49 – Overview, build quality and detailed specifications
05:51 – Full teardown, analysis and system architecture
18:00 – 10GbE PC interface using M.2 Key to PCIe converter
19:22 – Experiment #1: FMCW signal analysis, GUI overview & 160MHz capture capabilities
31:33 – Experiment #2: Interfering hunting, FM-versus-time, frequency hopping & advanced triggering
41:32 – Experiment #3: Digital demodulation, phase-noise & equalization
46:02 – Other GUI capabilities, mask & EM compliance, API
47:20 – Concluding remarks
In this episode Shahriar retrofits a vintage HP 8445B Auto Preselector for testing and characterization of high-performance data converters and oscilloscopes. The Preselector is in essence an electronically tunable band-pass filter with exceptional tuning range and quality factor.
After examining the schematic and block diagram of the instrument the unit is equipped with additional potentiometer, low-band, high-band switch and a voltmeter LCD screen which displays the center frequency. The modifications are applied to the front panel as well as internal circuitry to enable manual control of the preselector without the need for any external devices.
The modified instrument is used to measure the harmonic improvement of a 20GHz synthesizer. Several oscilloscopes are then characterized using the new preselector to determine the absolute performance of their internal data converter.
Finally, it is also time for a new giveaway! A brand new Keysight DSOX1102G scope! Patreon supporters are automatically enrolled.
The Signal Path (TSP) is an electrical engineering video blog for industry professionals, students and hobbyists. TSP is a non-for-profit website dedicated to provide free education spanning a wide range of electrical engineering topics. Equipment reviews, tutorials and repair videos are posted regularly.