Handheld scope recommendations

[dnix71]

I see a lot of handhelds still being sold with rs232 ports. That doesn't seem very useful in the days in USB. But I would like a battery powered scope for basic checking up on things. What's the minimum sampling rate that would be useful? There are a lot of pocket scopes that sample under 10MHz, which I have heard is kind of rough.

Most of the cheap scopes only have one input. What's the advantage of 2?

What type of display is preferred? I would expect a backlit for dim light, but in bright sun it might be hard to read some displays.

[joestue]

two inputs... so you can see the relationship between them, or perform differential measurements if the scope allows it.. etc..

i don't really see a point in buying those cheap ebay scopes such as http://cgi.ebay.com/ARM-Nano-Portable-Oscilloscopes-USB-Handheld-/160415866721?pt=BI_Oscilloscopes&hash=item255987df61 unless you want to get one just for the fact that you can extract the data and use it for data logging, for the simple reason that you can pick up a 2 mhz analogue scope for 20-40$, or get an old 20 mhz bandwith scope for around 40-60$

[gizmo]

I bought a little Vellaman 5MHz scope a few years ago, its been very handy for the windmills. 5MHz or 10MHz is more than enough for this type of industry, you only need to go to 20MHz or higher if your testing radio equipment or other high speed electronics.

I did have a 200MHz Tektronics 485 a few years ago, but never used the higher frequencies. It was a nice cro, but more than I needed so I sold it on ebay for a few hundred dollars. I now have the Vellaman portable and a bigger 20MHz bench dual trace.

Glenn

[jaskiainen]

This just got me thinking of buying my own scope.
What do you guys think of this http://cgi.ebay.co.uk/ARM-DSO-Nano-Pocket-Sized-Digital-Oscilloscope-2-8-/300458819103?pt=Radio_Control_Parts_Accessories&hash=item45f4bdbe1f#ht_4726wt_698

Is it any good for measuring "things"? At least the price won't hurt that much even after taxes...
I don't think i need 2 channel scope.

[frackers]

The Parallax PropScope is a possibility - dual channel, 25Msamples/sec, single USB connection to a laptop or other PC.

[JW]

Interesting Frackers,

I found this link http://www.parallax.com/tabid/768/ProductID/586/Default.aspx

Looks like a good deal for only $250 seems to be 25mhz per channel.

I paid quite abit more than that for my Fluke 123 scope. Ive got to send mine back for maintenance/calibration. Also it uses some sort of optical connection to a PC, I can get a software package for it called "fluke view".

In todays day and age is amazing at how many options one has for this sort of thing. For example, the link Jaskiainen provided as well, this stuff wasnt anywhere around ten years ago.

I think to measure 3phase you need sometype of "power quality analyzer" scope

JW