<> I agree but I would not recommend someone dropping a couple hundred bucks
<> fix an old 20Mhz scope as I am sure they would not limit their use
<
<It probably wouldn't cost anything like that much... Most older 'scopes
<are easy and cheap to repair.
I'd agree. generally most scopes are not to bad to fix but some are
definately more avoidable like the really old Valved units.
<> *exclusively* to vintage minis. A 20Mhz scope in RF/High speed logic
<> troubleshooting/design is totally useless. A 20Mhz scope isn't even very
<
<_Nonsense_. I've done a heck of a lot of troubleshooting on quite modern
<stuff using that 15MHz 'scope I mentioned earlier. It all depends on how
<you use your instrument and if you know how to interpret the results.
I agree. At the time the PDP-8 was common the 465 was the hotshot on the
block and few had one. I remember seeing 316s with the dual trace plug
in used for that!
<Maybe not Tektronix, but there are still 20 and 30 MHz 'scopes in the
<catalogues. And most of them are horrible -- they don't trigger properly,
the B&K, Hitachi and Leader are three I know well and they trigger OK,
say about as well as most of the HPs. ;) Seriously, they arent Tek,
they don't have that nice trigger but many others that are faster don't.
Most of the better 20mhz scopes really do see 20 and then some and a few
of the off brand faster ones don't. Tek is expensive, DSOs/DPOs are not
always interchangable either. All of this is mostly unimportant to
troubleshooting a errent core stack.
<etc. You'd be _much_ better off spending the money to fix up an old
<Tektronix than buying one of those. Of course if you can afford a new Tek
<with all the bells and whistles, well that's great!.
If you can fix one, some of them can be had for a song. a few are really
collectable on their own merits. I'd really like to have a 316!
<At least one company seems to define an 'x MHz scope' as : If you turn
<the Y gain right up and apply the maximum allowed signal then you'll see
<_something_ at 'x MHz'. I am not joking...
Some are pretty poor. The NLS MS15 is in that pool. However being battery
operated and a 75$ investment back in 76 made it a fair little scope even
now.
OH, that core... there is a switch on the g111 module and if misset the
core will not work. It sets the slice time for the read amps. If wrong
the code has stuck bits or worse flakey ones.
The other thing that can go off is the current drivers, if the current
level is off... no write, no read.
Allison
Received on Tue Nov 23 1999 - 21:38:17 GMT