[mythtv-users] Video Noise and VHS-to-DVD conversion (long - only read if interested)

Brian Wood beww at beww.org
Sat Jan 6 16:25:32 UTC 2007

On Jan 6, 2007, at 8:30 AM, Dewey Smolka wrote:

> I had only known a 'humbucker' as a type of electric guitar pickup and
> thought the name was just because it sounded cool. I hadn't realized
> that setup was designed to eleminate noise -- ie buck hum.

The "humbuckers" I was talking about are small boxes with 2 BNC  
connectors designed to reduce hum in video circuits. The guitar  
pickups of the same name operate on similar principles, both use  
opposing coils to null out AC hum.

The video humbuckers do not, however, break the ground path, and thus  
do not help with ground loops and other common-mode problems. Optical  
isolators do isolate the grounds, but the problem is that they are  
active circuits which require either batteries or AC adapters, which  
can be a pain in the field.

> I'm really looking forward to Parts 2 and 3, and I think that once
> they're complete the whole article should find a permanent home on the
> wiki.

Much thanks for the kind words, and it will certainly wind up in the  
wiki eventually.

More information about the mythtv-users mailing list