Oscilliscope - Good deal?

[Tom Cloud]

>I have a business card from a vendor who has a $25 dollar HP122AR
>Oscillicope.  It had a sweeptime range of 5 to 200 usec per cm.  That's
>good enough for fuel injection stuff, isn't?  The damn thing was huge and
>old.  Round, orange screen.  It did have A, B, and A&B channels.  Outside
>reference feeds.  What I liked about it was the lack of hundreds of
>incomprehensible buttons and dials whose function I have no idea of.
>
>The vendor said he was using it up to two months ago and it fuctioned then.
> Is it a good deal?  It would cost me $10 bucks in gas to go get it, but I
>could make them plug it in and proved it worked.
>
>Thanks,
>Joe Boucher
>'70 RS/SS Camaro  '81 TBI Suburban
>

In my 1989 Tucker catalog, the 122AR is listed at $595 (working, warranteed);
it's a 450 kHz bandwidth -- adequate for audio work -- barely adequate
for efi work -- you'll be real unhappy real soon when measuring any
digital signals -- the rise and fall times will look like RC time
constant charge/discharge curves rather than sharp edges and you'll
not be able to diagnose in-circuit ringing (i.e. you'll probably
be able to see ringing from injector coils, etc but not from traces
or other signals that are quite fast).

For $35, it sounds like "what the heck"  ....  but if the 122 is a
vacuum tube device, then it'll be a real hassle waiting for the tubes
to warm up and drift around -- and one bad tube can cost you $35 to replace.
Plus, it'll be BIIIG and H.E.A.V.Y !!  Still, if I were a kid wanting
to play (i.e. just learning and no money) I'd jump on it.  OTOH, as
someone else said, you can likely get a used 50 MHz or better dual trace
scope for $200 or so.

Tom Cloud