Buying first oscilloscope, trying local first, but need help - Page 1
Forum section: electronics / beginners

author: mcderdav
author_rank: Newbie
timestamp: July 03, 2014, 02:08:57 am
content: I started into electronics in December, but I never bothered to buy an oscilloscope because they're fairly expensive, but now I need to be able to see the signals that are happening in my project. I wanted to buy local to save on shipping, but I only found three somewhat questionable listings. All of them are about an hour's distance away, but I need to go in that direction soon anyway. I was just unsure of the quality of these scopes and if the prices are good for these models.The listings are:Two LBO-515B Oscilloscopes for 200USD (75-150 USD for one on ebay)One INSTEK GOS 620 Oscilloscope for 100USD (50-500 USD on ebay)No images listed, listed as new in box from 2000A lot of Phillips scopes with one HP scope for 200USD (Unknown value on ebay)Personally I'm intrigued by the first and last listings because of the images and the scope/dollar rate, but I really don't know what brands are trustworthy (I know tektronix, agilent, and other top brands, but they're expensive), and I'm viewing this through craigslist, which I don't have much experience with.

author: echen1024
author_rank: Super Contributor
timestamp: July 03, 2014, 02:22:44 am
content: Agilent used to be HP...But that HP 1741 scope is a real workhorse and a really nice scope to use.

author: elliott
author_rank: Regular Contributor
timestamp: July 03, 2014, 03:13:59 am
content: The HP/Philips lot is tempting, but it looks like most of the Philips scopes are scrap. If that HP works I would consider working a deal with the seller for it on its own.The bandwidth of the Leader scopes isn't the greatest, but it might be enough for your needs. If they both work well you could keep one and sell the other. I'm not seeing a service manual available for it though, which would concern me.

author: KJDS
author_rank: Super Contributor
timestamp: July 03, 2014, 06:56:08 am
content: If you were looking to buy a first car then going to a scrapyard and buying a pile of 10 is not the way forwards.Your first scope needs to work properly

author: robimarko
author_rank: Regular Contributor
timestamp: July 03, 2014, 11:28:21 am
content: Quote from: KJDS on July 03, 2014, 06:56:08 amWell you dont,if it does not work you can mostly repair it yourself like i did,and now 40 year old HP 1220A is working like in its early days

author: tautech
author_rank: Super Contributor
timestamp: July 03, 2014, 01:42:47 pm
content: If I were you I would get the Leader. New? hopefully in perfect condition and with manuals.As you are new to the hobby, there is much to learn and much to acquire.It is not a large outlay and treated well you can likely get most of your money back should you choose to upgrade later. Furthermore as they appear to be new, they are less likely to give problems and the frustration of old stuff.Really you don't want to spend all your spare time fixing your most important piece of test gear. You want to be learning and building stuff.

author: elliott
author_rank: Regular Contributor
timestamp: July 03, 2014, 05:45:03 pm
content: Quote from: tautech on July 03, 2014, 01:42:47 pmThey are still old, they have just been sitting in a box for 30 years.

author: Shock
author_rank: Super Contributor
timestamp: July 03, 2014, 09:27:33 pm
content: I can tell you that the pile of Philips scopes is junk and you will be lucky to get one good one out of it. They are rather old as well. If your going that old you might as well spend $200 on an old Tek.I recommend you instead look to pay $100 or more on something that looks decent with a trace on the screen and if possible with probes.When shopping for scopes you don't scrape the bottom of the barrel. It sounds like a lot now but a few hundred dollars will make the difference between off brand junk and a keeper.

author: simpson
author_rank: Contributor
timestamp: July 04, 2014, 12:49:17 am
content: I recently bought my first scope. I found it at a local flea market for $23 (haggled down from $25). It's an Hitachi v422 (40mhz). The seller knew nothing about scopes and there was no way to plug it in on site to test it but I talked to him about it, asked where he got it, what he saw when he plugged it in, etc and from his answers it seemed pretty likely that the scope was working. So, for 23 bucks I took a chance.It had no probes but I got it home and connected the channels to the calibration terminal via makeshift leads and saw two square waves displayed which responded as expected when I adjusted the controls. So, it looked good and I bought a set of probes on eBay for about $10 and a manual and now I have a working scope for experimenting and learning. I'm sure it probably needs calibration but, for my needs right now, it's a neat addition to my "lab" and seems to work fine with clean display.Next time I go out looking for a used scope I'm going to bring a probe with me and a power cord (used scopes are often missing one or both it seems) to make testing it on site easier.My opinion is, if you are on a budget like me and seeking an analog scope: For your first scope don't worry too much about getting a high quality one, just get one that works well, looks clean and isn't so old or obscure that you can't find a manual for it. Chances are you're going to get a better scope later anyway and the learning value of having ANY working scope is the most important consideration. I'm sure that not everyone here will agree with that but that's how I see it.

author: tautech
author_rank: Super Contributor
timestamp: July 04, 2014, 01:32:58 am
content: Quote+1Good advice.

author: edy
author_rank: Super Contributor
timestamp: July 06, 2014, 01:33:29 pm
content: You mentioned the sellers are not far from you... I would bring a power cable and probes...and see if you can go there and turn them on. You can clip onto the 1kHz calibration signal and try to get an image. Sometimes if you are buying from a non-electronics person or someone unfamiliar with scopes, they may not know what settings to use to get a trace. Or they may get a flat line and think the channel is toast, or they may get no image when the intensity knob is way down or they are in XY mode, or many other "traps for young players" as Dave would say. So you could end up passing up good gear or being tricked as well by someone who doesn't know better.That lot of old scopes may actually have 2 or 3 or even more good finds and if you clean them up perhaps you can sell a few and recoup your money and then some. However for a beginner it will not be easy... and I would want to at least plug a few in and not buy without knowing. Also find out how the seller ended up with them. Sometimes you have these old HAM guys who pass away and their kids sell the estate and you get a pile of equipment. Sometimes schools or governments or companies discard bulks of equipment and there is an aftermarket that deals with it for pennies on the dollar so they want a quick return.Someone said just to get something you know works even if you spend more. If you are a beginner I think that makes the most sense... unless you can test stuff at flee markets or the local ebay listings, perhaps pay more but get a listing that is from a seller that has tested and can confirm that it is working.