Easy free hack to increase 1x probe bandwidth?

[TopQuark]

For working on low level signals, I like using 1x probes, but the BW of these probes are quite low, often limited to around 10MHz or so. Reason being the distributed R, L, C in the lossy coax cable used in scope probes.

Today I had a silly thought: If the distributed loss in the cable is attenuating the HF contents, why not just make the cable shorter? I mean most of the time the probe cables are longer than I need anyways.

So I took a x1/x10 probe that I don't use anymore, snipped half of the cable length off, and terminated the cable with a crappy screw terminal to BNC adapter (terrible, but I don't have anything better on hand), and what do you know, the rise time decreased from 32.6ns to 19.6ns, giving us roughly 66% more bandwidth.

Halving the cable length didn't quite give us double the BW, probably because of the input capacitance of the scope channel being held constant. Signal fidelity looks fine. The 10x mode doesn't work properly anymore, but I have enough dedicated 10x probes anyways, I don't really care, I'll just glue the switch to x1.

So yeah, what do you think? Am I missing something? Or is it really that easy to get a better x1 probe (besides the listed drawbacks) ?

[alm]

This is a valid technique. If you look at the specifications for the old Tektronix P6101 1x probe, which was offered in 1m, 2m and 3m lengths, you see the bandwidth halve for every extra meter of length. I don't see a down side other than the obviously shorter length, and the need to modify the probe since I don't think anyone sells 1m probes anymore.

For 10x and higher probes this would also improve their bandwidth and input capacitance, but it would require changing components in the tip and possibly compensation box to match the lower cable capacitance.

[noisyee]

That actually works fine. I don't see any drawback.
I like to use a short coaxial with a damping resistor directly solder between the test point and the center conductor. So I always keeps some low value axial resistor in hand.

[jasonRF]

Nice hack - especially since you had extra probes laying around!

For small signal measurements I picked up one of the Cal Test ge2501 x1 probes.  It is 1.2m long and rated for 55 MHz, although if I recall correctly mine seems to be about -6dB at 55 MHz (-3dB at 35).  The longer (2m) ge2502 is supposedly 35 MHz.