Advice Needed Receivers with the lowest Symbol Rate?

[Channel Hopper]

Understood, though my concern is these are where the parabola is not being retained.

Can you undo the bolts on them, even a little ?

 

[Vipersan]

Understood, though my concern is these are where the parabola is not being retained.

Can you undo the bolts on them, even a little ?

I can slacken them off Stephen but I dont think the legs of the tripod which atm is copper tube are strong enough to deform the parabola.
The tripod legs would bow before anything moved on the dishes overall shape.
The cast tripod leg brackets are bloody tough beasts.
all that said there is a tiny bit of play available...but do remember there are L shaped cast brackets on the underside of the dish similar to the earlier photo..

 

[Vipersan]

I'm now repeating the annealing process again...this time marking both surfaces with sharpie and making sure both sets of markings vanish totally.
This ally strip is incredibly resistant to changing shape permanently.
having let it air cool all afternoon it still sprung back to near flat when removed from the wooden former.
There is evidence of curving but not sufficiently..
This is bloody tough stuff.
I might even apply the hammer a little

 

[Channel Hopper]

If in doubt, hammer and vise.

 

[Vipersan]

Not perfect but overall I am pleased with how they turned out...
Having cleaned and degreased them ..the first coat of auto paint has been applied.
..giving me time for a spot of breakfast.
..paint hides a multitude of sins ie hammer marks
The wood former will provide a second function ..in that it can be used to correct that rim bulge on the right side of the Christine

 

[Vipersan]

Even such a small deformation could be contibuting to her deafness...
Hopefully I can coax her back into shape.
Would you apply heat CH ?or just keep winding the G clamps ever tighter ?
Shes had this bulge since I got her...obviously a problem from when she had a previous owner.
Now I have the wooden former I figured ..time to try and fix it.
C band is very forgiving KU not so much.
rgds

 

[Channel Hopper]

The wood former will provide a second function ..in that it can be used to correct that rim bulge on the right side of the Christine

Are you likely to have a go at a shakedown ? The former could be used in conjunction with string and visual LOS across the rim.

 

[Vipersan]

Are you likely to have a go at a shakedown ? The former could be used in conjunction with string and visual LOS across the rim.

Indeed I will give her a shakedown at some point ...but as I said earlier ...I rate it a 2 man job so I can only do the shakedown when my mate is available.
Not putting it off permantly but just putting it aside for now.
Like I said ..getting the pre shake jobs done first.

 

[Channel Hopper]

Crossed posts. Now I see what you are trying to achieve and yes, unless the reflector is straight all round, not all signal will end up inside the scalar. With many distortions on prime focus you may have two or more sweet spots when the should be just one (and an equal drop off all round).

I doubt just clamping will be enough as thick aluminium will have some spring in it, you would need to deform slightly further than the desired profile for it to return. Perhaps a bit of leverage with a piece of long pipe at the right spot(s) rather than a mallet.

 

[Vipersan]

Crossed posts. Now I see what you are trying to achieve and yes, unless the reflector is straight all round, not all signal will end up inside the scalar. With many distortions on prime focus you may have two or more sweet spots when the should be just one (and an equal drop off all round).

I doubt just clamping will be enough as thick aluminium will have some spring in it, you would need to deform slightly further than the desired profile for it to return. Perhaps a bit of leverage with a piece of long pipe at the right spot(s) rather than a mallet.

If you look closely at the wood former there a slight steps at each end of the curve which I didn't rasp out...so my theory is that the centre of the curve could be packed with shims or washers acting as shims to push the centre of the deformation slightly past the natural curve point achieving what you descibed.
If ya catch my drift.

 

[PaulR]

Flip that's a rave from the grave with that Username surfacing. Welcome back Evan. I won't have much to contribute here (actually, probably nothing) but I do tend read a lot of the posts from time to time. Good to know you're still here.

 

[Channel Hopper]

If you look closely at the wood former there a slight steps at each end of the curve which I didn't rasp out...so my theory is that the centre of the curve could be packed with shims or washers acting as shims to push the centre of the deformation slightly past the natural curve point achieving what you descibed.
If ya catch my drift.

I did see the incremental tightening of the clamping screws, though not the former itself.

Did you keep any of Sheila's earlier giblets ? It might be wort checking the difference on each nearest the deformations on Christine for a pattern
(But a shakedown would be my first as you know, the current work could be a step too far and the issue just goes away.

 

[Vipersan]

So I guess that's all for today...
I left it as late as possible to allow the painted brackets to dry hard.
..but it is now too dangerous for me up ladders in the gloom.
All three brackets are on but only finger tight until tomorrow.
The top one you cannot see but the bolts might be visible.
a good days work imo.
rgds
VS

 

[Vipersan]

I did see the incremental tightening of the clamping screws, though not the former itself.

Did you keep any of Sheila's earlier giblets ? It might be wort checking the difference on each nearest the deformations on Christine for a pattern
(But a shakedown would be my first as you know, the current work could be a step too far and the issue just goes away.

sadly no I didn't keep any of Stellas gibbys ....except for the original extension panel wood and fibre glass mold ...just case I ever wanted to re-make those panels (doubtful now)...it's in the loft somewhere.

 

[Channel Hopper]

sadly no I didn't keep any of Stellas gibbys ....except for the original extension panel wood and fibre glass mold ...just case I ever wanted to re-make those panels (doubtful now)...it's in the loft somewhere.

Sheila is in the loft.

Understood.