mesh vs solid dishes

Channel Hopper

Maybe I need to post some 'nice dish' shots to get interest up again ?

There is a very fine line between "hobby" and "mental illness"

Simba27

I understand what you are saying about diffraction. The point of the exercise being to modify the dish such that the waves are reflected into the LNB rather then being diffracted. I'm not sure what you mean about an impedance mismatch or how that is relevant.

Having looked at my dish again, I can see why the experiment failed. The surface of the filled-holes is nowhere near as smooth as the surface of the metal. I do believe that some improvement would have been noticed if I had chosen a very fine filler, and then used micromesh to polish it really smooth - the dish having been made equivalent to a solid dish. However it's also true that the man-hours necessary to do this properly would be prohibitive.

As predicted earlier: I am not getting any less signal because I have not modified the existing surface. Unfortunately I am not getting any more signal because the surfaces I have added are not smooth and accurate enough.

Lancelot

Just a thought here, has anyone got any info on the projected RF reflective properties of 'ready mix easy grout' at 10 - 12GHz? .I suspect it would be absorptive rather than reflective unless you have some RF reflective spray paint to give it a couple of coats with.


L.

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I've got an inferiority complex, but it's not a very good one.

fawad

6 years ago at C band, i cover my chicken mesh dish with Aluminum foil tape
& i got improvements in signal, i think the nature of in mesh create a lot diffraction,
you did not find any change may be due to
1-properties of 'ready mix easy grout'
2 satellite signal you are receiving very strong??

spiney

What I said was, for wavelengths bigger than holes, the field only exists a short distance behind the holes - unless you deliberately extract energy - hence what you get is reflection, but it's not perfect, a solid dish is slightly better.

You can't "fill in the holes"! What you'd have to do is create a new solid continuous conductive surface with no rf impedence mismatches. There's no practical method of doing this at all, never mind as a DIY job.