At 22:00 12/12/98 +0000, Tony Duell wrote:
>
>Warning : Hunting for obscure Tek modules/manuals is at least as adictive
>as going after old computers. And you will have to get used to valved
>circuitry.
Amen to that Tony! Besides, I grew up on tubes (valves) since I was about
11 or 12. Greatly disappointed when in first year of college the course on
vacuum tube theory was eliminated (Fall of '71) because the instructor left
the school for another job late that summer. Instead I took 'Intro Computer
Circuits' (or some name like that) which was a revelation for me :)
>
>I have 3 scopes I use regularly. One is the Tek 555 I mentioned earlier.
>It's old, it's heavy, and it really can't be used 'in the field'. But
>it's got delayed timebase, sampler module, spectrum analyser, etc. Not
>all useful for computer repair.
>
I have a Tek 547 with 1A1 plugin (50 MHZ bandwidth), Tek 422 portable (15
MHz b/w), Tek 564 with about 8 or 9 different plugins (10 MHz max. b/w)
plus an HP 183 with 1830 plugin (250 MHz b/w) all of which which serves
much of my needs for fixing computers, radios, TVs, etc. Good tools.
>Another is a small, old, Solartron CD1400. Again it's valved, has a
>bandwidth of 15MHz (enough for a lot of work), I have the delayed
>timebase module, etc. This one gets used for tracing video signals (it'll
>look at colour subcarriers, etc), audio work, etc.
>
>The last is a Velleman LCD scope. I'd prefer a Fluke or Tektronix, but
>the Velleman is about 1/10th the price. It's only 500Khz, but it's enough
>to look at PSU ripple, motor drive signals, line output waveforms, etc.
>And it's easy to carry about, etc.
>
>One thing. A good second-hand scope (like a Tektronix or an HP) will cost
>about the same as a new low-end unit. There is no comparison in the
>quality, though - the Tek/HP is the much better instrument. And it's
>probably more reliable as well. I have had plenty of problems with some
>makes which have horrible triggering, non-linear timebase, etc.
Those 500-series Tek scopes are an engineers dream IMO. What a design! What
detail! What reliability! What serviceability! OT: has anybody seen in the
schematics of the older Tek scopes an occasional cartoon character? I can
reference several examples off-list. I went hysterical with laughter the
first time I stumbled onto one. What a hoot! Shows Tektronix was't such a
stuffy, nose-in-the-air company.
>
>>
>> Anyone who is getting into exploring and restoring digital stuff
>> at the hardware level should try and get a nice scope... it really
>> opens up one's capabilities to keep vintage gear running.
>
>I think my logic analyser gets rather more use than my 'scope. Of course
>which you use depends on what you're used to. And there are times when I
>_need_ a 'scope.
Wish I had a decent logic analyser myself. I just gotta get out to the
bigger hamfests and hunt one up one of these days. Used ones are more
available for reasonable prices with more features and performance nowadays.
>
>> Plus the learning experience would be interesting with an
>> oscilloscope of that complexity.
>
>I would not recomend learning to fix the 'scope as a first project,
>unless you enjoy that sort of thing...
>
>> And anyone wishing to get more info on scopes and how to use them
>> is welcome to e-mail me... I will try to help.
>
>Or post to the list. I'll probably respond as well, and the uses of
>'scopes (and other test gear) for repairing old computers is on-topic (I
>hope!).
If Tony doesn't see it or is stumped (not likely) I'll jump in and help
anyone too.
And yes indeed, being pretty much on topic is discussing the tools one
would use to fix his/her computers.
Regards, Chris
-- --
Christian Fandt, Electronic/Electrical Historian
Jamestown, NY USA cfandt_at_netsync.net
Member of Antique Wireless Association
URL:
http://www.ggw.org/freenet/a/awa/
Received on Sat Dec 12 1998 - 20:45:22 GMT