New here and could use advice on scopes - Page 1
Forum section: electronics / testgear

author: Skivt68
author_rank: Newbie
timestamp: July 25, 2013, 09:25:19 pm
content: Hello, first post here, been watching the YouTube channel for a while now. I've recently started working on more electronic projects and now feel that i could use an oscilloscope, however, I am not in the position to get a nice new scope so I have been hunting around for an older one. While looking I have come across some nice looking older HP models that are relatively cheap on ebay, specifically the 54520A, 54645d, and 54542A. What are your thoughts on these scopes and would they be suitable for a beginner who has only used an oscilloscope once or twice? Also, if I pick one up (any scope) how would I calibrate/test it without a proper waveform generator. I've seen people use 555 timers and/or pc sound cards as rudimentary waveform generators but i'm not sure how reliable and accurate they are.Thanks-Skivt68

author: free_electron
author_rank: Super Contributor
timestamp: July 25, 2013, 09:33:30 pm
content: 54645d is a really great machine

author: g0rsq
author_rank: Contributor
timestamp: July 25, 2013, 10:08:44 pm
content: As a bigginer I would stay clear of older digital scopes!The sampling rate is quite low for the bandwidth, and so the resulting display can be misleading, or quite deceptive. You really need to know what you are expecting to see before believing what you actually see.Also if anything goes wrong, then you end up with a piece of scrap, as repairs will be very difficult, if not impossible.The scopes you mention are nice scopes, but certainly not cheap scopes, and certainly not beginners scopes!What do you intend to use the scope for?If it is mainly audio, then a 500Mhz digital scope is not necessary!For a first scope I would suggest getting a very cheap 20-40Mhz analogue one, learn how to use it, and understand what is important to you.Upgrade when you have learnt what you want.You would be far better getting a decent function generator, along with a cheaper simpler scope.Peter

author: Skivt68
author_rank: Newbie
timestamp: July 28, 2013, 05:49:36 pm
content: Thanks for your replies, I have decided against the HP scopes. What do you guys think of the LG/Goldstar OS-9020A? It seems like I can get one for a good price and was wondering if I should jump on it. Quick replies would be helpful as it has only around 3 hours left.Thanks again,Skivt68

author: edavid
author_rank: Super Contributor
timestamp: July 28, 2013, 06:58:17 pm
content: Quote from: g0rsq on July 25, 2013, 10:08:44 pmThe 54520A is 500MSPS/1GSPS, the 54542A is 1GSPS, and the 54645D is 200MSPS, so I don't see any problem. They are all good scopes if the price is right.

author: edavid
author_rank: Super Contributor
timestamp: July 28, 2013, 06:59:55 pm
content: Quote from: Skivt68 on July 28, 2013, 05:49:36 pmIt's OK, nothing special. A lot of them come out of schools, so they are beat up.

author: Skivt68
author_rank: Newbie
timestamp: July 28, 2013, 07:26:06 pm
content: So what price would you recommend for the OS-9020A? Likewise for the HP scopes, as I am still watching them.

author: edavid
author_rank: Super Contributor
timestamp: July 28, 2013, 08:39:01 pm
content: Quote from: Skivt68 on July 28, 2013, 07:26:06 pmI wouldn't want to pay more than $40 for the OS-9020A.I don't know the current market for the HP models, sorry.PS The 54645D data probe is hard to find if it doesn't come with the scope.

author: Skivt68
author_rank: Newbie
timestamp: July 28, 2013, 08:55:56 pm
content: Alright, thanks. The 54645d ended a while ago, but the 54520A is still up for currently $100 with 11hrs left and the 54542A is $54 with 3 days left.

author: nctnico
author_rank: Super Contributor
timestamp: July 28, 2013, 09:18:50 pm
content: Quote from: g0rsq on July 25, 2013, 10:08:44 pmI tend to disagree. A digital oscilloscope can display aliasing artifacts but when its set to peak-detect it behaves mostly like an analog scope. OTOH a digital oscilloscope usually has features like FFT (frequency analysis) and the ability to make screenshots which are great to use in reports. I don't know whether the OP wants to pursue a career in electronics but most companies have digital scopes so knowing how to use one is a big plus. There are many excellent entry level oscilloscopes from Siglent and Rigol. For a beginner I'd recommend getting a new entry level oscilloscope.

author: Bryan
author_rank: Frequent Contributor
timestamp: July 28, 2013, 09:26:35 pm
content: Why not look at a good used Tektronix scope. Lot's on Ebay, and well nothing beats a analog Tek

author: Skivt68
author_rank: Newbie
timestamp: July 28, 2013, 10:14:24 pm
content: Thank you all for your replies, first to address nctnico, I don't have the funds currently for something like a ds1052e/1102e, I am looking for a good used scope on ebay. Secondly, to address bryan, I have been looking for a tektroix and I am watching some, but I already know about tektronix and know that they are a good brand, I was just curious what some of the other brands were like in case I found a better deal.

author: true
author_rank: Frequent Contributor
timestamp: July 29, 2013, 12:27:29 am
content: Quote from: Bryan on July 28, 2013, 09:26:35 pm...of which a lot are really aged and have failing components, or have custom ICs that can break and can't easily be replaced. Fine equipment, if well taken care of, but better deals for newer or less problematic scopes can be had on a budget.I can't personally recommend this, but others on this forum have. Only a little cheaper than the 1052E. I don't know what your budget is though. $270 shippedhttp://www.ebay.com/itm/Hantek-DSO5072P-Digital-Oscilloscope-2Channels-70MHz-1GS-s-7-TFT-WVGA-800x480-/350828701504