Vintage Oscilloscope (RCA WO-91A) for the broke student

[Mephitus]

You want to talk about vintage/old school scopes, check this vintage 1956 baby out. The dealer is local but posted on ebay for about $20 as of the time of this posting. I am pretty damn broke as I am trying to scrape together a few $ to go to college for EE, but was wondering if it was even worth considering older scopes like this if it was within what I could afford for such things right now? Yeah, it needs some deffinate work, but I would love the challenge.

[GreyWoolfe]

That looks to be of hollow state vintage (tubes/valves).  Unless you have good troubleshooting skills, know how to work around high voltages and have the proper tools, including a variac, to do so, I would pass.  I didn't follow proper procedure and bring voltage up slowly with a tube scope someone gave me.  The flames weren't really big and they went out when power was removed but the smell stayed around the house for a couple of days.  SWMBO was not pleased.  I learned my lesson.  The Tektronics 535A that I rescued from the dumpster sits on a diy cart as a conversation piece.

[The Doktor]

That was my 1st scope, 30-35 years ago. Paid $10 at local flea market. Still got it, just to remember how I got started. It's a horrible, low bandwidth, recurrent trace (no triggered sweep) scope that was basically obsolete when I got mine. Perhaps neat to play with, but not useful.

For under $50 you should be able to find a solid state, dual trace scope with at least 20Mhz bandwidth and triggered sweep. In working order as well, hopefully with at least 1 probe. Walk away from the RCA, even if you can get it for $5.


Ed

[SaabFAN]

Just be sure to add a few Caps to your budget.
You probably have to replace a few in the Power Supply.

I'd suggest to save a few more bucks and grab a Philips Combiscope. They can be had quite cheaply (just sold my 50Mhz,100MS/s PM3350 for 76€). They combine digital and analog functionality, and even include automatic measurements and readouts. For starters they should be enough. Unless you're trying to get into the high-frequency stuff right away

If you're just interested in analyzing digital signals, grab one of the Saleae-compatible USB logic-analyzers on ebay. They're about 20€ and offer 8 channels. Software is available for free and includes decoding-functionality for the most common protocols.

PS: Try to get to Germany or any other european country to study EE. From what I heard about the USA and its education-system, I think it's not impossible if not likely that you end up with less or even zero debt

[daqq]

Well, it's really about what you want to do with it - scopes like this are useful pretty much only for displaying frequently repeating waveforms within their bandwidth limit.

For analog that can be useful - to a point.

For digital stuff it pretty much limits you to checking if a clock is OK-ish, if there is any kind of signal at all present and PWM measurement.

20 USD is not much, but if I were you I'd save up for something better. If it is not in perfect working order add to that the cost of replacement parts, repair, and your time.

[Richard Head]

"just sold my 50Mhz,100MS/s PM3350"

I loved my Philips PM3350, particularly being able to switch between analog and digital at the push of a button. Eventually the calibration people smashed the front panel. Calibrated to death. Typical corporate company crap.

[Mephitus]

Good to know, thanks for the advice! I will just be patient, save up a few more bucks, and see about getting something a bit more up to date/functional. Though this is also posted locally and pretty cool. But I think if I am willing to wait a little more, I can probly wiggle into my school loan budget one of those Hanko DSO5XXX series since they can be hacked like crazy.