Interference bands on Philips 900NC image - help

[Astroman (Andrew Wall)]

Hi guys,

I was wondering if any of you had what looks to me like interference bands on a modded 900NC webcam? I tried using it lastnight and the bands appeared in all frame rates and they are just a pain for trying to find guide stars. The bands are equal in distance apart and run horizontally across the FOV.

I was thinking maybe a ferrite ring around the USB lead near the computer side?

[asimov (John)]

Yeah, most common on this camera. It becomes no problem once you stack out the data but in your case where you need to use it live...Not a good choice I'm afraid..

[Astroman (Andrew Wall)]

No worries John, just tried a ferrite ring but made no difference except make the cable heavier Looks like I may have to stick to my plan and get a ASI120mm or something like that.

[asimov (John)]

The only way is to lower the gain...Which will be no good for you if you need to pick up on faint stars to guide on.

[wasyoungonce (Brendan)]

Yes I was thinking gain and maybe gamma set too high.

[asimov (John)]

Seems to be gain more so than gamma that makes the lines more apparent. Gamma adds a fair bit of speckle as well..

[Astroman (Andrew Wall)]

Will have another play tonight if the clouds hold out, but think I might bite the bullet and order a ASI120mm from ZWO.