I just want to be done with this decision and go back to designing things!
The signals I would like to look at are:
- IQ baseband signal, differential but I don't think it matters, 20 MHz
- Your typical boring CMOS clock, <= 40 MHz
- 70-140 MHz parallel bus
The other signals I would like to look at but I probably cannot afford are:
- DDR2, 400MHz
- SerDes, too high of a frequency to even comprehend, it's probably best to hope the design just works.
I currently have your typical super cheap hacked rigol and a saleae logic 8 (I mostly work with RF).
So here is is my thought process and what I've been looking at:
- I'm ok with any hacking up to and including a couple of days of soldering.
- I don't think I need a MSO. I believe my logic 8 gets the job done. It would probably be a nice to have feature, but only if the scope is big/new enough to make the interface better to use than my pc. Sure looking at some signal integrity and triggering from it would be nice but it doesn't sound like a must have.
- I'm considering those scopes based on their resale value. I'm ok with spending 5k if I can get a good chunk of that back selling the scope in 6 months assuming that the project doesn't work out as planned.
- I'm in Europe and I can't find that much on Ebay. I even looked at the .com website, it looks to me like this is the wrong time of the year for used oscilloscopes. But I need it now.
So scopes I've been looking at:
1) Rigol DS4000, hacked to 500 MHz, Euro 2000 (I don't have to worry about VAT). The same with MSO can be had for around Euro 2800.
2) Rigol DS7000, the 200 MHz version for Euro 3000 seems attractive to me. With MSO it's 4000, it gets to 5500 with decoding. It seems like a stupid purchase to me because the moment it's hacked (tomorrow or in two years) the 2500 spent on unlocks will become worthless.
3) Siglent SDS2204X, Euro 1300 for a 200 MHz scope, an additional Euro 400 for MSO and unlocks. The 300 MHz version is 1700.
4) Keysight 3000T series. Let's say the 4-ch MSO 100 MHz option is 5k? It should be possible to hack the scope to 500 MHz and unlock all the options. I can't find it used on Ebay. The non-MSO 100 MHz option is Euro 3612. The 3000A series seems barely cheaper and I believe will have a slightly lower resell value, so I don't see the point.
5) The R&S RTB2004 is 2700 for 200 MHz with no MSO, adding MSO and decoding gets you to 4500 for 200 MHz. This is the scope with the nicest screen and probably interface, that should mean less problems using it, that makes it attractive.
6) A 2 channel 200 MHz Siglent is basically free, Euro 330. Some part of me feels like I should just go with this scope and re-evaluate in a month.
An extra, additional problem is probes. I sort of have the feeling a 500 MHz scope is going to be useless without at least one active probe.
I'm lost guys.