Fig 1. Rear view looking towards the front panel. The power supply is on the left and battery compartment is on the right. Some of the cables could be routed and tied down a bit better but they are probably OK.

Fig. 2. Bottom view showing the motherboard. The shield covering the input channels is removed. Each input channel is on a small daughterboard mounted above the motherboard. (The object in the upper right corner is part of my stereo zoom microscope.)

Fig. 3. Closeup of the ADC section with four Analog Devices AD9288 Dual 8-Bit A/D Converters (439KB pdf) running at 125MSPS, which is 25% above the maximum spec. Eight converters are interleaved to give 1GS/sec for a single channel.

This raises serious questions about the waveform sampling accuracy and long-term stability due to the extreme requirements of interleaving at these frequencies. For example, see the following article in the August 2003 issue of Analog Dialogue, "Advanced Digital Post-Processing Techniques Enhance Performance in Time-Interleaved ADC Systems" (900k pdf) . As shown in Figures 12 and 13, the errors due to mismatch cannot be trimmed out with conventional inexpensive ADC's such as the AD9288. Especially when eight of them are run 25% past their specifications in order to reach 1Gs/s.

The FPGA in the upper right corner is a Xilinx XC3S400 (54KB pdf). The white component marked AGQ200A4H appears to be a DPDT relay by Panasonic. Two of them are also used on each daughterboard.

Fig. 4. Looking towards front with the shield covering the input channels. The black cylinder with the plastic strap is a battery. The large IC to the left of the battery is an Analog Devices ADSP-BF531, 400 MHz Blackfin Processor that controls the oscilloscope.

Fig. 5. Closeup of the Channel 1 daughterboard looking towards the input BNC connector. If you look through the cutouts on the daughterboard, you can see additional circuitry on the motherboard. The white objects marked VC101 and VC102 appear to be trimmer capacitors.

Overall the quality seems quite high. The chassis construction is simple and straightforward, and the box structure gives a very strong assembly. Some of the cables could be tied down a bit better, but they are probably secured well enough for the intended application.

As you would expect, the entire instrument was very clean. I could not see any fingerprints, solder splashes, or other debris.