LeCroy WaveRunner LT224 DSO - Short review and teardown - Part 1

The following is a review of a LeCroy WaveRunner LT224 digital oscilloscope I wrote in another forum in March 21, 2013, and which I reproduce here for availability reasons (I no longer own that scope!):

Recently I acquired what is my first own LeCroy oscilloscope. I have used other LeCroys on various occasions but I always wanted to have my own. Why? Because they are still considered to be the Mercedes of scopes, due to their very advanced signal analysis capabilities. Unlike other scope manufacturers which target primarily electronics design/development/service, LeCroy comes from the physics and sciences corner and therefore has taken a somewhat different approach to their scopes, putting much more weight on the analysis tools. Especially older LeCroy scopes are also known for a somewhat awkward user interface, at least if one is used to the standard layout that is common amongst most analog and digital scopes (it's usually less a problem for physicists, mathematicians and other scientists).

However, while I always wanted my own LeCroy, I didn't want one of the old 9300 Series as they have become a bit long in the tooth with their slow 68k processors and monochrome CRT. I wanted something a bit more modern (1999 to 2000 vintage) and with color screen. That means either a LC Series scope (LC3xx/5xx with color CRT, LC6xx with LCD monitor, with bandwidths from 500MHz to 1.5GHz) which succeeded the 9300 Series in the highend market in 1998, or one of the new (at that time) midrange series called 'Waverunner LT' (200MHz to 500MHz). And finally, when the chance came up to get a Waverunner at a reasonable price, I just couldn't resist.

So what follows is a short introduction to the Waverunner LT, a short review of my particular scope and a semi-teardown of my 'new' LeCroy Waverunner LT224.


The Hardware:

The LT Series is the first generation of LeCroy's midrange oscilloscope series called 'Waverunner' which was introduced in 1998. The Waverunner LT scopes were produced by Iwatsu in Japan, however the technology and the software came from LeCroy, with Iwatsu merely serving as manufacturer (so it's not just a rebadging job like LeCroy did with the craptastic WaveAce Series made by Siglent).


1574628310037.png



1574628317311.png


The Waverunner LTs are compact bench scopes in a white casing, available in two-channel (LTxx2) or four-channel (LTxx4) configuration, with analog bandwidths between 200MHz and 500MHz and single-shot sample rates between 200MSa/s and 1GSa/s. They were later succeeded by the Waverunner 2 Series which was essentially a refresh of the first gen Waverunners with faster processing (same as the WavePro 900) and new aquisition systems which came in a blue casing. Both generations use the same firmware/OS package, built on Windriver's VxWorks, a dedicated Real Time Operating System (RTOS).

The successor of the Waverunner 2 LT is the Waverunner 6000 which runs Microsoft Windows and is based on LeCroy's XStream architecture and MAUI touch screen interface.

The Waverunner 1 LT uses a 96MHz MPC603e PowerPC processor and Enhanced Data Output (EDO) memory in 72pin PS/2 format (it can use Fast Page Mode (FPM) memory, too, albeit not officially supported by LeCroy). There are two memory slots. Basic Waverunner LT models come with 16MB or 32MB RAM (1x 16MB), which can be upgraded to 128MB (2x 64MB). Other components like the GPU (Chips & Technologies 65545 with 1MB DRAM) are connected via VESA Localbus (VLB) to the core chipset. The screen is a 8.4" 640x480 LCD displaying 256 colors out of a palette of 4096 colors.

1574628324731.png


The digitizer frontend comes with two (2Ch models, LTxx2) or four (4Ch models, LTxx4) 8bit ADCs with local sample memory, which sits on proprietary memory modules (HMM, Hybrid Memory Module) and can be upgraded with up to four modules (if you manage to get hold of the modules, that is). Basic configurations come with 100k or 250k of sample memory, which could be expanded up to 8M (4M per channel). The BNC inputs on the front also have a smaller connector with an I2C bus, which serves for communicating with the more advanced LeCroy probes. LeCroy calls this the 'ProBus' interface. It's the same system as used on the old 9300 Series and the old LC Series right up to the latest LeCroy scopes.

1574628331129.png


The Waverunner also has an PCMCIA Type II/III slot on the rear which can take a PCMCIA hard drive (up to 512MB) or one of the antique SRAM memory cards that were more common on the 9300 Series, which then serves as local mass storage. Unfortunately the slot is inactive unless activated through the HD01 or HDS software options.

1574628337989.png


There also is a 1.44MB 3.5" floppy drive (Citizen W1D) which is prone to malfunction as the drive belt (yes, this thing doesn't have direct drive) tends to dissolve itself, which can be fixed by either replacing the drive (some old Compaq laptops used a similar floppy drive) or the belt. Considering how useful 1.44MB of storage are in these days, it as well can remain unfixed.

1574628345236.png


Connectivity consists of GPIB (scope control), RS-232 (scope control or printer) and parallel port (printer). There is also a slot for an optional 10Mbps Ethernet network card which is basically unobtainium. And of course, like other LeCroy scopes of that era, an optional graphics printer was available, too.

1574628352807.png


The scope is cooled by a single fan only.

The build quality, probably thanks to Iwatsu, is very high, and in several areas a lot better than on the 9300 Series or the LC models.


The software:

The Waverunner 1 LT was LeCroy's first scope running Windriver's VxWorks embedded RTOS (9300 and LC Series use a LeCroy proprietary OS), which is used in many other applications as well. The user interface of the Waverunner LT is similar to that of the LC Series and the 9300 Series. In terms of features it's well equipped. From persistence mode (either color-graded or analog CRT-like), advanced triggering modes (SMART triggering, edge/slope/signal pulse width/signal interval/state or edge qualified/dropout/TV), zoom, segmented memory, ERES (Extended Resolution, something along the lines of Tek's HiRes mode, just a bit more sophisticated) and many other things one would expect from a modern DSO.

As with other LeCroy models, the scope functionality can be upgraded by software unlock codes. All Waverunner LTs already come with standard math, statistics and FFT packages which on the 9300 and LC Series were paid-for options (WP02, WP03) and which already exceed what is available on most other scopes (even modern ones). If this is not enough then there are several software options available: Enhanced Measurements and Math (EMM), WaveAnalyzer (WAVA), Jitter and Timing Analysis (JTA), digital filter package (DFP), Advanced Trigger (ATP), PolyMask Testing (PMSK), Power Measure Analysis (PMA1), as well as the specialist Surface Map Analysis (SMAP) and Disk Drive Measurement (DMM) for those working with hard drive internals (there's also ODM which is the same but for optical drives). Thanks to the faster processor, the Waverunner LT is much quicker in advanced analysis or math modes than the old 9300 Series, and is as fast as the highend LC Series.

LeCroy also offers a choice of free Windows applications for using the scope with a PC. ScopeExplorer can remote control a LeCroy scope, it can access the scope's mass storage (hard drive, floppy drive) and transfer files between scope and PC, and can update the firmware directly over the internet.

1574628359926.png


1574628365757.png


ActiveDSO is an ActiveX control for controlling the scope within other applications like Office and VisualBasic. DSOFilter is another ActiveX control for designing custom digital filters. MaskMaker is a too for creating masks for using with the PolyMask software option. The programs that actively control a scope can do so via GPIB, serial interface or network interface. And albeit only NI GPIB adapters are officially supported, the programs work fine with an Agilent 82357 or the Beiming 82357 clones in NI.488 mode.

Stay tuned for Part 2...
  • Like
Reactions: rsjsouza

Blog entry information

Author
Wuerstchenhund
Views
1,010
Last update

More entries in General

More entries from Wuerstchenhund

Share this entry

Top