The DirecTV SL3K4NR1-03

[Archive-8]

Still not functioning at pre Christmas levels ..but figured it was time to at least attempt to use the feeds designed by Trust ..
So dug out my unmodded SL3K4NR1-03 ...and srilled a couple of bolt holes for the plastic escutcheon thusly ..
Now to try the anti circular depolarisation dielectric mini plate in one of them ..
Rather than jump in making various attempts at dimensions ..
Anyone whos already made one ..care to share thickness/dimensions/ material types used for best effects ?
rgds
VS
Trying NOT to re-invent the wheel..
;)

I used an old capital one card cut to size. It's about time they did something for me :-)

 

[Llew]

My SL3-01 is unmodded, so as it's performing so well as it is, I'll leave it like that.

With the dielectric plate twisted clockwise 90 degrees, Teleppica on Horizontal shoots up, and the Vertical channels almost disappear, as expected.

 

[Vipersan]

My SL3-01 is unmodded, so as it's performing so well as it is, I'll leave it like that.

With the dielectric plate twisted clockwise 90 degrees, Teleppica on Horizontal shoots up, and the Vertical channels almost disappear, as expected.

Which is why I suspect I have mine fitted with the wrong 90 degree rotation ....
Tomorrow I'll try the correction ..
rgds
VS

 

[Archive-8]

View attachment 75098
Left hand is L+R right hand H+V
It's got 2 rt Ka feed horns. And capital one dielectric plate

H+V are the correct way around.

 

[Vipersan]

Ok ..
So it's nice and of course useful to be able to rotate the feed with the plastic plate to achieve either Heightened V and nulled H ...or through 90 degrees to Heighten H and null V ..
But in all honesty I cannot get more gain than that initial 0.5db with a empty feed (no plate) on Vertical signals with a modded SL3 (septum and lower resonance chamber removed) ....
Maybe some tweaking might get me a touch more ....and the feeds are beautiful ...plus the ingenious addition of the dielectric plate to skew the linear signals into a vertical plane ...makes a single polarity H or V easily selectable.
But for all that does not yet achieve our theoretical goal or seperating H and V without mechanical manipulation of the SL3 in some way..
For this we need a second probe at 90 degrees in the signal stream..
Whoever gets this one first ...in my mind wins the prize ..

rgds
VS

...One could of course do away with reception of RHCP and LHCP on the second non plated port ...and fit a second plastic plate in oppositon (90 degrees to the first port)
Thus both feeds having a plate ..
This would indeed give us selection of H and V electrically ...at the cost of losing or at least reducing either ports ability to receive unaltered true circular.
Effectively creating a psuedo Linear H/V 2 port lnb ...that can still receive compromised circular.

Now to get true circular back ...fit a second SL3 to the dish ...totally unaltered in any way except with addition of one of Trusts superb feeds ...and voila ...
you have true circular back ...simply by selecting the second SL3.
Gonna get a bit crowded on the dishes offset lnb arm ...but hey ...'tis worth it.

;)
I think this is the way I shall go for now at least

 

[Trust]

VS , I think using a plate to a inside modded lnb like yours make no sense .
Right this moment I receive Unire (hor) with 12.1dB and Newsnet (vert) with 10.4 dB with a inside standard lnb with a KTK feedhorn with 11.5 x 20 x 2 PVC plate ,without turning the plate !

edit : Unire is also comming in with 2.2 dB at Vertical

 

[Vipersan]

VS , I think using a plate to a inside modded lnb like yours make no sense .
Right this moment I receive Unire (hor) with 12.1dB and Newsnet (vert) with 10.4 dB with a inside standard lnb with a KTK feedhorn with 11.5 x 20 x 2 PVC plate ,without turning the plate !

Hi Trust ..
I'm not using a modded SL3 at the moment ..
The one currently fitted is a totally pristine unit with no mods at all ..
The feeds have been fitted is all ..and currently a plate inserted in the feed closest to focus..
I never receive huge signals at my location with the SL3 about 5 to 8 degrees off focus on a 1.5m offset dish.
Obviously a choice has to be made as to bias for horizontal or vertical ..
Not possible to have maximum signal on both at the same time..

regards
VS

 

[Vipersan]

So ...I had to try with plates in both ports of the internally unmodified SL3-01 ..
Right most port approx 8 degrees off focus ..
Left Port approx 5 degrees off focus ...
Thus The rightmost port (biased for H) receives less signal than the Left port which is closer to focus ...and plate set in left port to bias for Vertical signals.
..and obviously I had to shift the dish a few degrees between the 2 crazyscans..
Note the 22khz is on for V and off for H

 

[Trust]

VS , did you moved the lnb backwarts after attaching those feedhorns to get the right focal lenght ?

 

[Vipersan]

VS , did you moved the lnb backwarts after attaching those feedhorns to get the right focal lenght ?

Not yet Trust ..
A job for the weekend I think
;)
I'm sure there will be a bit more to be had once done ...but not expecting miracles here..
Newsnet for example is rarely above 9.5db at my location..
rgds
VS

 

[Vipersan]

So ...
no doubt you are curious as to how much circular polarity is affected by the insertion of a second plate into the feed of what was previously the unplated rightmost port of the SL3 ..
Well ..
in the case of Avanti ...H/LHCP on Hylas 31.5E ...
Signal has dropped a little from 17db to 16.2db
and the minimux on Turksat (TeleSahel) 42E ...also H/LHCP..well it fared a little worse ...dropping from 9.8db ..to around 7.5db and fluctuating more than before as it hunts for the best lockable signal.
Point being ..
Both are still lockable ..viewable ..and useable at these levels..
Therefore a second SL3 will not at this point be neccessary.
..and the 2 plates can stay..
Maybe you will want to do the same.
?
rgds
VS

 

[Archive-8]

So ...
no doubt you are curious as to how much circular polarity is affected by the insertion of a second plate into the feed of what was previously the unplated rightmost port of the SL3 ..
Well ..
in the case of Avanti ...H/LHCP on Hylas 31.5E ...
Signal has dropped a little from 17db to 16.2db
and the minimux on Turksat (TeleSahel) 42E ...also H/LHCP..well it fared a little worse ...dropping from 9.8db ..to around 7.5db and fluctuating more than before as it hunts for the best lockable signal.
Point being ..
Both are still lockable ..viewable ..and useable at these levels..
Therefore a second SL3 will not at this point be neccessary.
..and the 2 plates can stay..
Maybe you will want to do the same.
?
rgds
VS

I will have to give it a try tomorrow.

 

[scopus]

On my SL3 I receive Avanti at the same levels as I did before. I'm using the horn feed side which has had the septum removed and chamber ground out. I get them on both polarities at the same level on the Alien3. I will test the levels later on the X finder. Turksat is received also at the same level as before on the new feedhorn side with the dielectric plate fitted. I will also check if I can Turksat on the horn side later.

 

[Trust]

Since I modded both of my BBC adaptors , I cannnot receive the high KA band as for Hylas .
Will it do when I just cut the 5 volt wire in the BBC ?

 

[scopus]

Since I modded both of my BBC adaptors , I cannnot receive the high KA band as for Hylas .
Will it do when I just cut the 5 volt wire in the BBC ?

You don't need a modded BBC for Hylas. I have two cables to a Diseqc switch, one with modded BBC for Ka band A and a unmodded BBC on the other port for band B (Hylas) Remember, with modded BBC it is permanently 'ON'

 

[Vipersan]

So I guess today is one of those days when the Newsnet signal tops 10db here ..
actually peaked at 10.7db ..
but nothing to see ..
Locked with a blank black screen ..
Doh

 

[Vipersan]

Since I modded both of my BBC adaptors , I cannnot receive the high KA band as for Hylas .
Will it do when I just cut the 5 volt wire in the BBC ?

Just bypass the BBC ..and go straight to the SL3..
It doesn't have to be in circuit for the higher band.
Scopus is spot on.

rgds

 

[scopus]

VS, do you think one of these BBC's would work with an Inverto or Triax to give us Band A?

 

[Vipersan]

VS, do you think one of these BBC's would work with an Inverto or Triax to give us Band A?

Sadly No ..

..and I think if it did work youd receive Ka band C not A
I've already tried it ..
LO + recieved frequency ...
LO - recieved frequency...
I suspect the saorsat lnbs are constructed in such a way as to remove the residual composite frequencies as these are not needed or intended ..
unlike the directv lnbs which positively use this feature..
Clever I calls it..
;)

 

[scopus]

Thanks VS, I thought you might have already give it a go.;)