I just finshed building my 900mhz transmitter frequency is ok when i connect my video camera into the transmitter i get a herringbone pattern . I belived that its a grown loop problem . How can correct this problem

 

Maybe your circuit is oscillating.
you forgot to attach your schematic so we cannot help you.

 

can a growh loop in 900mhz video transmitter cause herringbone pattern
herringbone only when the external video camera c0onnected

 

Yes. Herring Bone patterns result when an interfering signal beats with another, such as the frame rate or the line rate. Such things happen when power supply noise or other periodic signals get into the video (such as spurious oscillations).

Would you please show your schematic and maybe somebody can spot the area in which you are likely to find the problem.

 

Attached is a copy of my 900mhz video transmitter

 

Thank you.
Can you post the file in an internet browser-friendly format such as GIF, TIFF, or PNG?

 

i beleive its in tiff

 

attached is tiff file for 900mhz tx

 

attached is tiff file for 900mhz tx

attachment 900mhz

 

I just finished a 900 mhz video tx every thing works fine clear picture. When i install in a metal enclosure i get herring bone pattern . I beleive that it being caused by pcb board dielectric. How can i correct this problem