Why does nobody talk about static discharge on weather radars?

I was helping a buddy bench test a Collins WXR-2100 last Wednesday and noticed he skipped putting a ground strap on the antenna before powering up. Said he'd done it that way for years and never had a problem. But I've seen two units get cooked from ESD because the waveguide seal wasn't making proper contact. It only takes a 20 second walk across a carpeted hangar floor to build up enough charge to fry the receiver front end. Has anyone else had to replace a radar board just because someone forgot to ground the dish?

2 comments

2 Comments

angelacooper11d ago

...I mean honestly, how often does that actually happen in real world conditions? I've been around these radars for almost fifteen years now and I've never once seen a board get fried from ESD. People get so hung up on static discharge but the real weak point on those WXR-2100s is the magnetron drifting out of tune after a hard landing. I think the whole ground strap thing is way overblown by the manuals. If you're careful and touch the chassis before you start, you'll be fine nine times out of ten.

lisa_brown10d ago

Last Wednesday I zapped myself so bad on a hangar door handle I saw stars for five minutes. Walked over to the radar bench, touched the chassis, and still managed to kill a perfectly good receiver board because my wool sweater decided to betray me. That magnetron drift you mentioned is real though, had a buddy chasing a ghost on a 2100 for two days before he realized the waveguide was just loose. Ground straps are like wearing a seatbelt in a parking lot, mostly you'll be fine but that one time you forget the carburetor on your truck is the same day you hit a pothole and bite your tongue.