[Elecraft] WAY OFF Topic question - Opto Isolator - USB - Weather

[Dan Barker]

For the full story of how-why-etc, click "About" on
http://weather.visioncomm.net.

Anyhow, I bought this weather equipment, and the manufacturer says the
reason the windspeed on the Weather station ($200) goes to 99MPH whenever I
plug in the RS232 connector ($150 option) to the computer (Never mind<g>) is
due to a ground loop. The fix is an "opto-isolator ($55 option).

I object.

I objected originally to $150 for the RS232 adapter (especially since the
software that comes with it is useless), but I REALLY OBJECT to $55 more to
fix what sounds to me like a design flaw.

My question to the group (thanks for the BW) is:

  Is an RS232 to USB adapter likely to fix this?

  Would some capacitors likely fix this? (choke didn't)

  What the heck do they mean?

 If I put my (100mhz) 'scope on the wires (it's only 4 wires, undocumented,
but most likely ground, transmit data, receive data, and mystery wire), what
should I look to see?

btw: If you've followed along closely, you might notice the wind on my
website at LESS than 99mph (currently, it's 11 at 329 true: 15:43 EST). My
laptop does not exhibit the symptom, only every other single server in the
joint (and I have 12).

I'd like to plug the weather station into a fixed server, and put my laptop
back where it belongs - Next to my K2!

There, I feel better now.

Dan / WG4S / K2 #2456