...Model 556 - dual beam CRT, uses 'letter series plug-in's'
...Half tubes and transistors, quite large...
...Has a unique CRT and replacements may be hard to find...
...Excellent dual beam scope, more oscilloscope than most people need...
A few suggestions for scopes that might interest us coilers:
...Specal purpose oscilloscope designed for testing high voltage line
surges and transients...Not very senxitive to small signals because it's
range is approximately 50 V/div to 500 V/div...Input impedance of 72 Ohms
and sometimes as low as 50 Ohms...Requires no plug-ins and uses a seperate
power supply...unique power supply and connecting cable...Replacement CRT's
will be nearly impossible to find...
...Storage scope, uses special difficult/impossible to find CRT, 30 Mhz
bandwidth, triggers well, uses letter series plugins and would be great for
one-shot scopeing of sparkgap performance and/or primary/secondary ringdown...
Models below the 515 are antiques, difficlult/impossible to get parts for
and very poor performance.
Tek also made quite a few models that are very special, and use CRT's that
can't be found, so check out the CRT very carefully before purchace.
Stay away from any type of sampling head plugin, they are easy to blow and
impossible to repair.
The 551/55 models use somthing like 30 matched pair tubes in the vertical
amp alone, and run really hot and are expensive to fix when they break, which
they do frequently due to the heat generated...
Most Tek scopes will work well, it's just next to impossible to get parts.
It might be a good plan to get two of the same kind and use one as a source
of parts to keep the other running. This isn't as expensive as it sounds,
since a lot to older Teks can be had for $25 at hamfests/fleamarkets etc..
All of the above is based upon my limited experiance with Tek scopes and
Tesla coils, YMMV...
I'd be happy to supply further opinion upon any given model, just ask !
Daryl (who like Malcom, has popped his share of modern test equipment...)