EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: perdrix on December 06, 2018, 03:32:22 pm
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I just got a new to me Iwatsu SS-7840 (aka LeCroy LA314) from an auction here in UK. It seems a nicely put together 'scope designed to compete with the Tektronix 2456B.
(https://www.eevblog.com/forum/testgear/a-look-inside-an-iwatsu-ss-8740-(lecroy-la314)-400mhz-analog-scope/?action=dlattach;attach=589666;image)
As they say don't turn it on, take it apart!
Power supply, HV, Horizontal and Z-Axis
(https://www.eevblog.com/forum/testgear/a-look-inside-an-iwatsu-ss-8740-(lecroy-la314)-400mhz-analog-scope/?action=dlattach;attach=589672;image)
Detail of conformal coated sub-board in PSU
(https://www.eevblog.com/forum/testgear/a-look-inside-an-iwatsu-ss-8740-(lecroy-la314)-400mhz-analog-scope/?action=dlattach;attach=589696;image)
Vertical board plus detail of CRT termination - can anyone give me any idea what the wire stub on one side of the termination is for - my guess is that it has something to do with the bandwidth variant that goes to 470MHz?
(https://www.eevblog.com/forum/testgear/a-look-inside-an-iwatsu-ss-8740-(lecroy-la314)-400mhz-analog-scope/?action=dlattach;attach=589678;image)(https://www.eevblog.com/forum/testgear/a-look-inside-an-iwatsu-ss-8740-(lecroy-la314)-400mhz-analog-scope/?action=dlattach;attach=589684;image)
CPU board (lower left) and main board with delay line (lower right)
(https://www.eevblog.com/forum/testgear/a-look-inside-an-iwatsu-ss-8740-(lecroy-la314)-400mhz-analog-scope/?action=dlattach;attach=589690;image)
I was amazed to find that the CR2354 backup battery soldered to the CPU board in 1997 still has a good charge on it!
Now if only I can find an IE-1066 Adjustment Jig (calibration fixture) to go with it!
Dave
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Neat! So Japanese... Thanks for sharing.
Did you get that blue CRT filter off in the end? :-BROKE
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Really nice Dave, what a score ! :clap:
Thanks for sharing the teardown photos, loved how you picked few detail close up spots. :-+
It seems a nicely put together 'scope designed to compete with the Tektronix 2456B.
Honestly, even though I own a Tek 2465B :P, this SS-7840 is one of my dream scope too, I guess I'm too greedy. :palm:
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I used to own one of these. Very nice analog scopes but I wish it had a full set of attenuators on all channels.
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I have a 7810. The manual contains the schematic for the IE 1066 (electrotanya has the manual). It is just some logic, opamps and a very early audio DAC with parallel inputs, a PCM55.
You can also use a PCM54, which is what i did :)
(http://members.home.nl/baltusg/JIG.jpg)
Works great, apart from the buzzer. Never got round to figure out what is wrong there ;)
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Very nice! The V amplifier looks rather effortless for 400MHz performance, at least compared to my HP 1720A's.
The brochure I saw mentioned 470MHz only in certain V/div setting for the SS-8740H, for the rest "only" 440MHz, so it might be more like an input related thing, or cherry picking some key components.
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Hi Guido
I'm assuming that you built that yourself? If so do you have any spare boards? Or would you share the Gerber files?
Thanks
David
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Hi,
Yes. No. Yes. Contact me offline :)