Mike wrote:
Reworking the workbench to be a little more builder-oriented and a little
less as a fix-it area, so I am considering a scope for the first time. I've
used them very little in the past, but I'm relatively sure that a 50 MHz
would suffice for me here as I don't operate higher than 6 meters. I do know
that short probes with minimal capacitance can be important, but I need some
help with knowing how much to get without overdoing or under doing it.
What's out there that would work for joe average ham as a decent scope? Cost
is always a factor, as is relative ease of use and learning curve (English
major here). Single trace? Dual? Lots of bells and whistles? Few? Particular
brands? Brands and models to stay away from?
You will likely get a variety of responses. Here's my tuppence worth:
As far as features and capabilities, a fully-featured scope will do
things you don't even know yet that you will want to do, and you'll
be very glad you got it when that time comes. For the most part, you
can just ignore the fancy features until you need them. The
workhorse has, for many years, been the 100 MHz dual-trace "portable"
bench scope with delayed sweep -- with very good reason. This
instrument can do the vast majority of what anyone needs, and they
are plentiful so prices are reasonable.
First-quality scopes (Tektronix and HP) are available used for very
little money these days, so IMO anything less (Leader, B&K, etc.)
should only be considered if it's free. '80s- and '90s-vintage
scopes are cheap and plentiful, so there is no need to look at '70s
and earlier Tek and HP models, either.
I am very partial to the HP 17xx series -- my 1742A, which I
originally purchased new in 1982 and which was on and working 10-12
hours per day for its first 15 years, still meets its specifications
and the screen looks as new. IME, HPs are generally easier and less
costly to repair than the equivalent Tektronix models (the Tek 465
series is particularly difficult and costly to repair). A
properly-working HP 1740A or 1742A can be had for $50-150. Even a
properly-working Tek 2465A digitally-controlled analog scope
shouldn't run more than $200-300 (the 2465Bs cost more because they
were the last of the line, but they aren't any more capable).
So, unless the budget doesn't extend as far as $100, I'd get a 100
MHz dual-trace HP or Tektronix from a reputable seller.
Most people use 10x probes almost exclusively, but for completeness
you'll probably want a couple of 10x and a couple of 1x probes. IMO,
name-brand (Tek or HP) probes are well worth the money over generic
probes. If you shop carefully, you can get good ones for $15-25 each
(though you'll see many listed for ten times that). Make sure the
compensation capacitor range on the 10x probes matches the input
capacitance of the scope (this is generally clearly marked on both
the scope and the probe).
These days, you will also find digitizing scopes in the $200
range. However, to get similar performance (>/= 50 MHz "one-shot"
capability) and quality to the analog scopes mentioned above, you
would probably need to spend $400-$900 (the Tek TDS2xxx scopes would
be the ones to look at, IMO).
Best regards,
Charles
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