Used 2GHz+ BW 4Ch Oscilloscope Advice and Question - Page 1
Forum section: electronics / testgear

author: jplle
author_rank: Contributor
timestamp: March 02, 2022, 06:16:29 pm
content: Hello All,I'm in the market for a used 4 channel oscilloscope with at least 2 GHz bandwidth. I want switchable 50 and 1M ohm impedance.Application is general high-speed signal and transient analysis, FPGA and minor aerospace work.Price range is ≤ $10,000.Many of the LeCroy scopes are perfect; however, many of them on the used market only have 50 ohm inputs. Some of their probe adapters are scarce as well.I'm interested in their WR 6200/WP 7300, WP960, DDA-260/204xi/WM series.Some others I don't know and can't find much about:Tek TDS74xxBAgilent infiniium 548xxA/BI found a Tek TDS7404B with some good serial options for $7500. Does anyone have any experience with this series of Tek scopes? Any known issues? How about the Agilent 548xxA/B series?Any other scopes anyone would recommend?Thank you for the help!

author: nctnico
author_rank: Super Contributor
timestamp: March 02, 2022, 06:34:31 pm
content: I'd skip the Tektronix TDS7404B like scopes. They work slow and they might need external tools for calibration.The Lecroy WP7300A is a good contender but it is LOUD. You can uphack the 7100 and 7200 to 7300 though by removing some capacitors from the circuitboard and installing a license. Infiniium 548xxA/B are also nice but seem to have less features in general.For a budget of $10k you should be able to find something a bit more modern though. $7500 for a TDS7404B seems very expensive to me. You can find much better deals on Ebay.

author: Venturi962
author_rank: Regular Contributor
timestamp: March 02, 2022, 06:41:05 pm
content: It seems that some 2GHz Infiniium scopes only have 50 Ohm Impedance per the datasheets (high impedance requires an adapter - E2697A), so I think you'd want to remove those from your list.https://www.testequipmenthq.com/datasheets/Agilent-54852A-Datasheet.pdfhttps://www.testequipmenthq.com/datasheets/Agilent-DSO81204B-Datasheet.pdf54846A (2.25GHz) does have switchable inputs but has small (32K / 64K) sample memory.https://www.testequipmenthq.com/datasheets/Agilent-54810A-Datasheet.pdf

author: jplle
author_rank: Contributor
timestamp: March 02, 2022, 06:46:21 pm
content: Excellent, thank you.I don't mind the fan noise, I find it soothing haha.I figured that price might have been a bit high. It actually was on eBay.You said I should be able to find a more modern scope and my price range? I search "oscilloscope GHz" on eBay and add a price filter $2k-$10k and unfortunately have not found anything more modern in my range.

author: tautech
author_rank: Super Contributor
timestamp: March 02, 2022, 07:21:36 pm
content: $10k gets you anewSDS6204A !

author: nctnico
author_rank: Super Contributor
timestamp: March 02, 2022, 07:34:55 pm
content: Quote from: Venturi962 on March 02, 2022, 06:41:05 pmBut it won't do 2.25GHz with 4 channels as in 4 channel mode, it only has 4Gs/s. Also these DSOs don't trigger on signals over 1GHz. OTOH the trigger system is really good. I used to own a 54845A and I'd say it has less trigger jitter compared to the Lecroy Wavepro 7k I have currently.

author: jplle
author_rank: Contributor
timestamp: March 02, 2022, 07:44:40 pm
content: Quote from: tautech on March 02, 2022, 07:21:36 pmI have considered this, yes. I do like Siglent. I'm using one now as my general scope. However, I felt as if I can get more for my money buying used. I have found some LeCroy scopes for half of the Siglent cost which have double the bandwidth and sample speed

author: nctnico
author_rank: Super Contributor
timestamp: March 02, 2022, 07:58:58 pm
content: Indeed. Including mature firmware and better trigger jitter specs in most cases.

author: tautech
author_rank: Super Contributor
timestamp: March 02, 2022, 08:00:11 pm
content: Quote from: jplle on March 02, 2022, 07:44:40 pmOK good however I urge you to look at the bigger picture for what you get with these new 6000A models.5GSa/s with all channels active, 10 GSa/s ESR, 500 Mpts shared and a host of acquisition modes to suit all needs.I'm yet to check the actual BW in my 2 GHz model but without a leveling head for the RF gen results can only be indicative. Anyways, these are lots more scope than 5kX and 2kX Plus.Get in front of one to try if you can.

author: jplle
author_rank: Contributor
timestamp: March 20, 2022, 04:23:28 pm
content: UPDATE:I ended up snagging a mint LeCroy WavePro 760Zi with calibration (6GHz 40G/s) and a WavePro 7300A XXL which has an unknown, locked XP login for less than $10K for both!This is why I didn't want to buy brand new. Amazing deals to be had

author: nctnico
author_rank: Super Contributor
timestamp: March 20, 2022, 04:39:41 pm
content: Quote from: jplle on March 20, 2022, 04:23:28 pmThat is a really nice catch!Well done. With some patience good deals can be found.

author: mawyatt
author_rank: Super Contributor
timestamp: March 20, 2022, 05:17:07 pm
content: Very nice indeed!! That would be a good catch even if they weren't working!!!Where does one look for such great deals, eBay?Best,

author: nctnico
author_rank: Super Contributor
timestamp: March 20, 2022, 10:20:19 pm
content: Quote from: mawyatt on March 20, 2022, 05:17:07 pmEbay is a good start but some have come across really good deals at auctions as well.

author: jplle
author_rank: Contributor
timestamp: March 22, 2022, 02:42:04 pm
content: Quote from: mawyatt on March 20, 2022, 05:17:07 pmI found the 760Zi from a large, reputable test equipment reseller and the 7300A on eBay. I'm pretty sure that they forgot to add an extra zero to the 760Zi's price. I asked for a quote for a 7300 they had (non A model, no options). And as most of the retailers do, they send you a quote for the scope you asked, plus another similar spec scope to give you more options. They quoted the 7300 at 8K and the 760Zi at 7K!! My jaw dropped. I played fair and asked why a scope that is 10+ years newer with 2x the BW and 2x the sample rate was 1K less. The salesman basically said that it was the price in their inventory of which he had no control. I immediately bought it and asked if they had more hehe. I paid for a calibration because I don't plan on keeping it. Even though it will be so so very painful to sell it, I would much rather sell the 760Zi and use the profits from the sale to buy a 7300A with a few nice active probes and other nice accessories and still have some cash left over.The 7300A was bought from an eBay seller who frequently sells LeCroy equipment from a lab local to his area. I bought a few ProBus interfaces and some 6Ghz probes from him at more, insane prices. I setup notifications on new items from him. He listed the 7300A with a locked, unknown user password. I made him a low offer and he accepted. It took only a few minutes to clear the password via some program that I installed on a bootable USB flash drive.Honestly, most eBay sellers list their scopes at way too high of a price and don't accept reasonable offers. The only scopes that are in the correct price range are either in bad shape and/or are overseas listings. Generally, I have gotten much better quotes from online test equipment resellers. Their scopes are in much better shape, come with much better warranty, and most of the time come with calibration.