More project madness

[Captain Jack]

VS, I know you love Christina but have you considered replacing her with an offset design?

 

[Channel Hopper]

Just in time for a hurricane......

 

[Vipersan]

VS, I know you love Christina but have you considered replacing her with an offset design?

I have actually considered it ...but rejected it almost immediately ..
a) cos the more vertical profile for a similar sized dish would almost certainly hit the wall to the East when pointed to the extreme East ..
b) cos Christina is a working antique and deserves much respect ...between 25 and 30 years old I suspect
c) cos PFs do perform well ..even petalised ones in C band
d) esthetically I love PFs ...they may not be the most practical of dishes ..but they are beautiful.
e) much work went into her restoration and petal extensions.
f) I don't want to hurt her feelings.

Sad I know ..but that's me I guess ..
an old sad nutter whos loved her for almost half his life.
;)

 

[Vipersan]

So..there it is ..
Fully weatherproofed ...fully adjustable ...and ready for mounting.
..but for some 2cm M5 stainless nuts and bolts that should arrive tomorrow or Tuesday.
For now I shall just mount as is and test ..but eventually the choke - feed plates will be conjoined to make one almost oval feed/choke with one of them having priority...
ie mostly complete ..a full circle whearas t'other will be only 2/3rds complete..where they overlap.
rgds
VS

 

[Riverblue]

I like the fact that you're logged on to the forum in the background of pic 1!

 

[Vipersan]

Very windy outside ...and showers to boot ..but the final nuts and bolts arrived today and impatience drove me up the ladder for a fitting in the dark..
Here are the results with 0ne large and one small choke/feed fitted..
The large ringed lnb being circular.
I managed an amazing 6.2db on the pentagon channel ..which is my reference channel.
with very little EL correction and a 1.5degree shift ..
Not going to try moving Christina much further tonight..but I just thought I'd share the results ..which quite frankly are blowing me away ...considering there has been NO adjustments made to the dual lnb bracket or lnbs etc ..only V-box correction..

rgds
VS

 

[Vipersan]

The wind has dropped a bit so risked sending Christina to 37W ...to test a linear bird on the second ESX lnb ..
I will have to rotate the lnb through 90 degrees tomorrow as the H is V and vice versa atm ..
Silverbird received at 8.2db
and Metro at 11.7db
I do believe this construction is going to prove invaluable in the future ..and still potential for a bit more signal with some tweaking..
rgds
VS

 

[Vipersan]

Well I knew there would have to be some trade-offs with this but overall I am pleased not to have to climb ladders and remove plates in winter..
So far I have lost the ability to lock anything at 17E ...but then the only constant here was Oromiyaa which was an odd lock around 5db ..
Best I can manage now is 3db
Nothing locks at 43W ...but then it rarely did anyway ..
Occasional Cholusat ..but now not a hint of anything.
I am rarely getting less than 5.9db at 1W (TPC) ...
and a blindscan at 55W pulled 170 TV channels ..
A couple of borderline channels have gone awol ..but all in all a good result.
I guess I have a choice to make..
return to a centrally mounted lnb and constant plate swapping ...or accept the trade-offs.
rgds
VS

 

[Captain Jack]

Nice piece of work there, Evan.

 

[hvdh]

It looks quite like I imagined it!
But instead of being mounted in parallel, can you let the LNB's point to the centre of the dish? That should give some improvement.
That will also make it possible to get them closer, by sacrificing a bit more scalar ring of course.

 

[Vipersan]

You are correct buddy ..
By eating away at the scalars slowly ..I hope to find the optimum point of max signal ..
Though this may take a few attempts ..

Since I haven't any extra scalars ..I cant afford any rash cuts to them ..
Any spare ones bought by those with offset dishes that would like to donate their PF scalars ..
?
lol
rgds
VS

 

[scopus]

You are correct buddy ..
By eating away at the scalars slowly ..I hope to find the optimum point of max signal ..
Though this may take a few attempts ..

Since I haven't any extra scalars ..I cant afford any rash cuts to them ..
Any spare ones bought by those with offset dishes that would like to donate their PF scalars ..
?
lol
rgds
VS

I might have a couple in the workshop VS, let me take a look when I get home.

 

[Captain Jack]

I think I have two scalars for PF dishes somewhere, which are of no use to me. You are welcome to them.

 

[Vipersan]

Appreciated guys ...since the only way to stockpile these is purchasing more lnbs ..
The more I have ..the greater the room for experimental error ..
;)
rgds
VS

 

[hvdh]

I do wonder however, why you chose the asymmetric approach for cutting the scalars?
Too bad the inner ring of the left scalar is broken...
A good compromise might have been, to keep the inner rings intact, and give both scalars an equal straight cut, such that the inner rings touch. Then, the centre-to-centre distance between LNB's would be about 10 cm.

 

[Vipersan]

Chose the Asymetric approach simply because the satellites in my visible arc are predominantly circular ..
So I gave the circular lnb a bias ...
But of course ...If I have access to more scalars ..I can make an equal unbiased version to test ...
Whichever suits my needs best I will adopt for use on a regular basis ...but can always switch this out for a biased version.
rgds
VS

 

[Vipersan]

Just out of curiosity ..can someone help me out with a small problem..
Currently trying to relocate certain satellite positions on the arc ..and not having access to a useable reference around 43 / 45 W ..the only thing I can lock is a data transponder but can't fix it's origin ..
3583 V(R) sr 30000 fec 3/4 ... 32APSK
A largish hump in the trace 4db plus ..
No idea if it is 45W but suspect it may be ....but _could_ just possibly be 43W
rgds
VS

 

[hvdh]

That's NSS-806 @ 47.5° West (see Flysat).

The frequency could have been a clue as well, both 43 and 45 West do not go below 3700 MHz.
You might check that URL in my signature more often... ;)

 

[Vipersan]

That's NSS-806 @ 47.5° West (see Flysat).

The frequency could have been a clue as well, both 43 and 45 West do not go below 3700 MHz.
You might check that URL in my signature more often... ;)

Cheers Hans ..
and yes I should visit you more often ..
rgds
VS

 

[scopus]

Appreciated guys ...since the only way to stockpile these is purchasing more lnbs ..
The more I have ..the greater the room for experimental error ..
;)
rgds
VS

Yes, got two you can have VS. PM me your address, I will get them in the post tomorrow bud.