"Andreas Tekman" wrote in
oups.com:


Jim Yanik schrieb:



IMO,the SC504 is a piece of useless crap.
It's display is too small for anything other than monitoring.
It has no BW limit,and you get too much noise picked up,especially
considering the small graticule.
It's not the sharpest CRT beam,either.

He'd be better off buying a T932/935 or a 442 (35Mhz) scope than a
SC504. Even better; a 2235 100Mhz scope.
Any of those would also be more maintainable than the SC504.
And FAR better "cost-effectively".


For 7K mainframes;
7603 is a good choice,7704A or 7904/A better.
7A26 is the best of the 1MegZ 7K vertical plug-ins.
It has a 20 Mhz BW limit switch.

AVOID 7300,7400,7500 series!!



Well, the SC504 is worth to consider if you are fond of the TM500
series idea.

A Good idea,EXCEPT for scopes.

The SC plugin fits nicely as a plugin. If you need a
simple scope and small space is a reqirement, SC504 and 502 are the
ones to think about.

SC502 15 Mhz,IIRC.
But the graticule is still TOO SMALL for any useful work.
To be honest,I think I'd rather have a PC based scope than a SC5xx scope.


But for a serious wjob, you're better of with a 7xxx or 2xxx series.
Sharper trace, easier to repair, more efficient work. The 7xxx here
around are so incredible cheap to buy nowadays, and offer so much
flexibity for working. If you have the space, to place such an
instrument, it's really worth buying it. It'll serve you for years,
and it's always a pleasure to do measurements with such a fine scope.

But getting harder to maintain,full of TEK-made ICs.Switch contacts are
going to be a problem;the HF cam sw. contacts will eventually degrade.I've
already heard of the gold contacts falling off the spring beam,because the
white plastic cam follower crumbled.



The T9xx are the plastic (vacuum cleaner apperance) scopes. It's a
matter of taste. surely not the best scopes Tektronix ever made, but
for hobby use more than adequate.


hth,
Andreas



The T900's are the most serviceable;they don't use any TEK-made ICs,the
attenuator contacts are one strip that can be removed for cleaning.If one
resolders the cracked solder joints from the case flexing,then they are
nice beginner scopes. Good size CRT graticule.
And very inexpensive!


--
Jim Yanik
jyanik
at
kua.net