Iwatsu TS Series Oscilloscopes

[Anquietas]

I have been looking at TS series scopes [1] from Iwatsu for quite some time now and despite the fact that they have been discontinued I wonder why they have left such a small digital footprint. What was so ... bad about them that nobody seemed to want them? Despite the possibly quite high price. You can get Iwatsu SS series scopes on eBay, but TS series are nowhere to be found except for one online account [2] that may very well be out of date.

If you know why this interesting oscilloscope technology didn't take off, please share your knowledge. If you happen to have a service manual for a TS series device that would be awesome.

[1] http://www.iti.iwatsu.co.jp/en/products/ss/ts81000/ts_top_e.html
[2] http://www.testequipmentconnection.com/42968/Iwatsu_TS-81000.php

[Hydrawerk]

Maybe those scopes were too big, heavy, complicated, expensive and too dificult to repair??
That refurbished Iwatsu TS-81000 costs $19,556.00 http://www.testequipmentconnection.com/42968/Iwatsu_TS-81000.php
On the other hand, the new 1GHz Agilent DSOX4104A with 4 Channels costs $17,233.00
http://www.newark.com/agilent-technologies/dsox4104a/digital-storage-oscilloscope-4ch/dp/28W2472

Or you can get even cheaper scope dsox3104a http://www.newark.com/agilent-technologies/dsox3104a/oscilloscope-4-anlg-1ghz-5gsps/dp/75T5128

I would buy the DSOX4104A... Well, you see, that Iwatsu TS-81000 must have been very very expensive, when it was new. 

[alm]

Don't expect the used test equipment vendors to ask fair prices. They also ask $4k for a Tek 2465, for example. This is about 10x the eBay price. This scope cost about $7k twenty years ago. The only customer that would pay these kind of prices is a company in desperate need for one because changing a procedure (might involve recertification) would be even more expensive.

[nctnico]

The TS81000 seems to be a scope with scan converter tube. The trace is captured on a storage CRT and then digitized by a camera (or something like that). Lets say its a scope within a scope and a fast way to get a fast high bandwidth digital scope without needing high speed ADCs.

You can also buy a Tektronix TDS700 series which does 1GHz on 4 channels for about $1500 or a TDS694C which does 3GHz on 4 channels for about $3000 or a TDS820 which does 6GHz on 2 channels. All very old models though. And there are many more sampling scopes with 1GHz or more bandwidth not to forget analog scopes... Iwatsu (owned by Lecroy for a long time) has made some excellent scopes. I've owned an analog scope and a digital scope made by Iwatsu.

[Wuerstchenhund]

Iwatsu (owned by Lecroy for a long time)

Iwatsu is not, and never has been, owned by LeCroy.

The only relation between those two companies is that Iwatsu was OEM for some upper low end (WaveJet) and midrange (WaveRunner LT) LeCroy oscilloscopes (the WaveJets are rebadged Iwatsu scopes, the Waverunners have been developed together by LeCroy and Iwatsu for LeCroy).

[Wuerstchenhund]

I have been looking at TS series scopes [1] from Iwatsu for quite some time now and despite the fact that they have been discontinued I wonder why they have left such a small digital footprint. What was so ... bad about them that nobody seemed to want them? Despite the possibly quite high price. You can get Iwatsu SS series scopes on eBay, but TS series are nowhere to be found except for one online account [2] that may very well be out of date.

There was nothing particularly bad about those oscilloscopes. Iwatsu's main market always has been, and still is, Japan. 
Iwatsu is also a relatively small company compared with other T&M manufacturers (Tektronix, HP/Agilent, Hameg/R&S, LeCroy), they don't have the R&D budget of the big names, and being a Japanese company, they are bound to the Yen which usually meant that their products were expensive on the global market. Due to the lower R&D budget their scopes also often lacked the innovation and new technology found in devices from the other brands. All this resulted in Iwatsu being a rare bread outside Japan.

As I said, there's nothing wrong with their scopes, which are generally very solidly build and highly reliable.

Is there a reason why you want the TS Series which doesn't use an ADC but a scan converter tube?  Aside from the high bandwidth (which with adequate probes is useless) it's a very basic scope. Considering that Iwatsu scopes are rare and relatively expensive, you may be much better off with a different scope (i.e. a DSO).

[Hydrawerk]

Due to the lower R&D budget their scopes also often lacked the innovation and new technology found in devices from the other brands. All this resulted in Iwatsu being a rare bread outside Japan.

Well, it is a crazy idea to have a DS-5554 500MHz scope with only 1GS/s per channel. Welcome to the 1980's... http://www.iti.iwatsu.co.jp/en/pdf/ds-5500_e.pdf
Even the obsolete Tektronix TDS3000 is 500MHz with 5Gs/s per channel. http://www.tek.com/oscilloscope/tds3000 But this was designed in year 1999.

[jpb]

Due to the lower R&D budget their scopes also often lacked the innovation and new technology found in devices from the other brands. All this resulted in Iwatsu being a rare bread outside Japan.

Well, it is a crazy idea to have a DS-5554 500MHz scope with only 1GS/s per channel. Welcome to the 1980's... http://www.iti.iwatsu.co.jp/en/pdf/ds-5500_e.pdf
Even the obsolete Tektronix TDS3000 is 500MHz with 5Gs/s per channel. http://www.tek.com/oscilloscope/tds3000 But this was designed in year 1999.

That scope is a minor update of the WaveJet (1M instead of 500K memory per channel). I've just bought a 2006 (old stock so never used) WaveJet 334 and apart from the noisy fan I'm very pleased with it. If you use just two channels it is 2GS/s per channel otherwise it is 1GS/s but that seems to me to be sufficient. If you take the normal view that you can use a scope for signals up to about 1/5 of the bandwidth and that for linear interpolation (sadly it doesn't do sinc(x) interpolation) you want around 10 samples per wavelength then 1GS/s and 500MHz correspond to signals up to 100MHz. (My 334 is just 350MHz bandwidth - but it has the same specs on sampling.)

Though I've not had the scope calibrated I've compared the dc accuracy (against a 5 1/2 digit meter) and it was almost spot on (around 0.3% or less). On ac (the calibration signal) the meter and scope differed by a bit more but still under 1%. The impedance of the ports at both 50 ohms and 1Mohm was also in agreement with the meter (measured with 4 wires the difference was around one part in a thousand - I don't have the exact figures to hand).

Measuring the frequency of the 1pps signal from a GPS module (which should be within 10nsecs) was measured by the scope frequency readout as 999.998mHz so about 2ppm out.

The noise floor seems good. Overall I think that they are very well constructed scopes that are a bit out-dated design wise. I've not tested the screen refresh rate (don't have the equipment yet) but the nominal is 3,600fps which is slightly better than the Hameg but rather worse than more recent scopes.

I wouldn't pay the full asking price for one (certainly not a WaveJet), but as it cost me less than a 70MHz Agilent DSOX2004A and much less than a 4 channel Rigol I am very happy with it.