question about focal link

[dan00]

I have a 12 foot Sami dish and the manual says the focal link needs to be 57 inches and 5/8 with the FD rating at 3.8.
Making some adjustments with out trying to bend the three legs on my dish, the closest I can get is 58 inches and 1/16. With it being 1/2 inches off from the feedhorn ring does it make much difference?
I did see an increase in my C-band and KU signals after making these adjustments. My FD rating is set at 30 trying to make up the 1/2 inch difference from the ring.
Is the Feedhorn ring mainly for holding the feedhorn or does it have another purpose as well? I have a Chaparell Corotor 2 Plus Feedhorn. Thanks alot.

 

[FaT Air]

If possible, place spacers where needed, to move the scalar/feed closer to the dish. May require longer bolts.
(Spacers between the scalar and the struts maybe)
Might Upload some pictures to show what's what - and may get some 'refined' answers.

Is the Feedhorn ring mainly for holding the feedhorn or does it have another purpose as well?

It's to control the illumination of the dish and minimize the probability of reception of external noise sources. Terrestrial interference - T.I. be it natural or man made .

manual says

but that Still may not be the 'sweet spot'. Might find further improvement even closer, only 'tweaking' will tell.
(I'd put the scalar back to the .38 F/D mark)