Tube oscilloscope: use it, or cannibalize?

[cdwitmer]

My curiosity is piqued by a 1968 Japanese tube oscilloscope being sold by an individual here in Tokyo, and I wonder if anyone has any comments on it. It is an Ando Electric (still in business) "BPM-1105 Memoryscope" (there is also another number, AS-70042, given in the manual). This DC-10MHz storage scope with delay sweep function weighs 40kg (90 lbs.), and comes with 44 spare (unused) tubes. It seems to work fine. It also comes with probes, a stand, and a massive manual (mostly circuit diagrams). Trouble is, it's bulky -- 17" (H) x 13" (W) x 28" (D) -- in a country where space is always at a premium. The spare tubes aren't anything extraordinary (listed below); they have their various uses in preamps or small power amps. I'm torn between getting this to use as a scope for audio equipment (since I need a scope), and getting it to tear apart for amplifier parts . . . I figure if it weighs that much it must have some useful parts inside.

The spare tubes are --
Toshiba: 6DJ8 x 16; 6R-A3 x 2; 6AQ5 x 1; 6U8 x 7; 12AL5/M3623 x 2; 12AU7 x 8.
Hitachi: 12AX7A x 2.
Electronic: 12RY7A x 2.
NEC: 6CL6 x 4.
National: 6AU6 x 1.

What sorts of other parts useful for audio am I likely to find inside? Is it a real pain to keep a tube oscilloscope running? Or should I just pull out parts for use in tube amps?

Thanks!

[Circlotron]

Maybe you could use the (balanced output) high voltage deflection amplifiers and EHT supply as a basis for experimenting with driving electrostatic speakers. DC to 10 Mhz shoud be good enough!

If you can get the thing for free or next to nothing then go for it, otherwise buy a brand new one if you can afford it. 40kg is a bit much to lug around to your friend's house or whatever. If these kinds of equipment were not such a triumph of engineering built in the days when so few parts were available compared to now, they wouldn't command the awe they often do. Sometimes you have to look at this stuff for what it really is, an inconvenient and old fashioned, low-spec piece of almost worn out junk. Sad but true. Of course, it is better than nothing at all. Even I can see that.

[Le Basseur]

Originally posted by cdwitmer
-- in a country where space is always at a premium.

I'd use it as a pillow,if I'd had it!
Since you have all the documentation and the spare tubes,keep it and use it.The tubes you need in audio can be found elsewhere,without destroying a working scope (no matter how old or bulky it is).
Cheers,

[SY]

Looks like a copy of a Tek. If it works, I'd use it. If you've already got a scope, then look inside and see if it's got the Tek Treasure: those wonderful ceramic terminal strips.

[jackinnj]

probably uses identical circuitry. Nice delayed trigger. This was my first scope. Nowadays people give them away.

[cdwitmer]

ROTFLMAO ! ! !

[Circlotron]

Original cost ~£600 !

Yikes! You could buy a brand new car for that much in those days. Most of the cost was probably for the labour-intensive method of assembly on tagstrips. If it had been done on pcb's in a sensible sort of way it would have probably cost quite a bit less (or more likely a much greater profit margin )

[316a]

Originally posted by SY
Looks like a copy of a Tek. If it works, I'd use it. If you've already got a scope, then look inside and see if it's got the Tek Treasure: those wonderful ceramic terminal strips.

They are treasure ! I picked up a TEK565 earlier today for £20 . More gold pin 6DJ8's than I can shake a stick at and literally hundreds of those ceramic strips . I'm taking the plug-ins into work this evening for dismantling , better than work I suppose !

316a