I only have upper 20s MHz oscillators, so I can't really compare. But, with a 28MHz oscillator, I get nothing like a square wave. On 10X. The duty cycle of the output is pretty obviously 50% by the way.The reason I asked you to measure rise times in 1X mode is because the bandwidth is greatly reduced in that mode, so rise times should be long compared to 10X mode. You should be aware that if you want the full bandwidth of the scope, you can't use the probe in 1X mode.
Typically, the bandwidth and rise times for scopes are better than the spec.
On eBay you can find low cost scope probes that are considerably better than their advertised specs. For example, these are probably more like 200 MHz bandwidth rather than 100 MHz:
http://www.ebay.com/itm/Two-x1-x10-...020?pt=LH_DefaultDomain_0&hash=item334f669144
This probe is specified to have a bandwidth of 4 MHz in 1X mode. The bandwidth in 10X mode is much more than 100 MHz.
See this thread for more info about these probes:
http://www.eevblog.com/forum/produc...t-100mhz-oscilloscope-probes-hands-on-review/
I've attached two images. The first shows the output from a Rigol function generator set to generate a 20 MHz square wave as displayed on a Tektronix TDS210, which is a 60 MHz scope. The Rigol spec says the rise time should be 5 nS.
The second image shows the same signal as displayed on an Agilent DSO5034A 300 MHz scope. The measured rise time is 4 nS.
These two images were captured using the low cost probe referenced above which I bought on eBay.
One way you can generate a square wave with a fast rise time is to get a 74AC74 flip-flop (the AC series is Fairchild's "advanced CMOS" family). Connect the flip-flop to divide by two and feed it with the output of one of your clock generators. The rise time of this part is just a little more than 1 nS when properly wired and bypassed.
Your scope should be able to display a 20 MHz square wave at least as good looking as the TDS210 image.
Also, I discovered my probes are indeed 100MHz, so that can't be the issue. What good would a crystal oscillator be if it didn't truly output a decent square wave.