Swapped my old scope for a $40 USB one, big mistake

I used to carry a beat up Tektronix 465 around for 8 years, checking every signal with those knobs and that heavy CRT. Then last spring I figured I'd save space and bought a little USB scope from Amazon for 40 bucks. The thing worked fine for simple stuff like checking oscillator outputs, but when I tried to chase a weird glitch on a Collins radio, it just showed garbage. Turned out the USB adapter had way too much noise and I wasted 3 days chasing a ghost. I dug the 465 back out of the storage closet in Wichita and found the problem in 20 minutes. Anyone else ever downgrade their test gear to save space and regret it hard? What did you switch back to?

1 comments

Log in to join the discussion

Log In

1 Comment

michael_craig3d ago

Did you ever stop to think the USB scope wasn't the real problem? A $40 widget plugged into a laptop that's also charging, with a wall wart feeding the radio, is basically a noise factory. The scope is getting blamed for what the grounding setup is doing. Your 465 has a big metal case and a real power supply, so it shrugs off all that junk and just shows you the signal. I bet if you put that cheap USB thing on a laptop running off battery and used a decent shielded cable, it would've found your glitch too. Half the "bad gear" stories I hear are really floating ground stories in disguise.

1