KA reception is a no go so far for me

[Vipersan]

Been in bed with a nasty flu bug for a few days ...but had to drag my carcass into work today ..
Just as my ka lnb arrived this morning ..
So aching I climbed the stepladders and swapped out my Cband lnb for the inverto dual polarity dual output lnb.
Got the Alcoa aligned on 9 East...in an attempt to lock ...saorsat..and certainly not expecting anything ..and such I was rewarded ..
Nada..
..but for the occasional burst of signal which barely made 1db on the F15 ....and that was sporadic at best.
Now there are many issues in play ..
Dish to small at 1.8 m for my location ...plus ..the lnb was designed for an offset ...and not my pf..
So am on a hiding to nothing to start with ..
Sadly I can't even find a solid consistant signal to peak the lnb at the ...errr...focus ..
Plus my dish is a petal design and as such tends to be ineficient even in ku.
Question..
Is there a constant ka signal source from any bird aimed at the UK that I might have a chance to aim for and setup the lnb (optimise ) ??
so little to go at ..such tight beams ..that the persuit of ka broadcasts are indeed going to qualify as 'fringe' reception ...though the intended reception areas are mere hundreds of miles away.
I have more chance of receiving South Africa than Northern Ireland
Ironic isn't it..
but thats the future ...and I'm not relishing it.
rgds
VS

 

[william-1]

Hylas 1 @ 33.5° West has 8 active transponders with much bigger footprints than KA Sat @ 13 east,
flysat.com/hylas1.php there are KA band transponders also active @ 23.5 east,19.2 east 13 east & 4.8 east,
I have no idea what frequency they use as they are mainly used for broadband.

 

[Vipersan]

Thanks William ...I'll try your recommended birds ..
At least that way I should be able to test the lnb ...polarity is correct and possibly optimise its position at the focus.
rgds
VS

 

[Channel Hopper]

Tbh, I doubt you will get a sniff off any of them. The 9E footprint is currently the strongest one out there at this location

Is your Ka band LNB polarised correctly ?

Test card only

20185
Left hand circular
25000
1/2
QPSK DVB-S2 MPEG-4
1101/1201/1101


_http://www.satbeams.com/search-137?ordering=newest&searchphrase=all&searchword=Ka+band

 

[Vipersan]

Tbh, I doubt you will get a sniff off any of them. The 9E footprint is currently the strongest one out there at this location

Is your Ka band LNB polarised correctly ?

Test card only

20185
Left hand circular
25000
1/2
QPSK DVB-S2 MPEG-4
1101/1201/1101


_http://www.satbeams.com/search-137?ordering=newest&searchphrase=all&searchword=Ka+band

Seriously not expecting much CH ...
..but figured there must be at least 1 data transponder aimed at the UK
Tooway for example offer a home internet service to the uk that is ka based ...and afaik originates from 13 E
Surely this isn't based on a 3m dish requirement
If it is ..they won't do much business in the uk
;)
rgds
VS

 

[Vipersan]

...Looking at the lnb I still can't figure out how its possible to seperate RHC and LHC within the actual lnb
Obviously this cannot be a physical depolarizing process ...like the introduction of a plate at 45 degrees to the probes ...as both signals arrive at the same point within the lnb waveguide..
...and since we are talking about circular polarisation ..it would suggest there is no such thing as correct skew orientation to the lnb postion..
but this might be a total misunderstanding on my part ..since the depolarisation must be done electronically ...and its dual output remember ..
But does this mean RHC on one output and LHC on the other ??
In which case switching polarity would be done externally with a diseqc switch..
Damned if I can find a pdf or indeed any setup info for this lnb ...
Does anyone know how it actually works..
rgds
VS

 

[Chris76]

scan 10764
Right hand circular or vertical
25000
1/2
qpsk

im unable to scan anything on the old test card, so there is hope yet old bean

Good luck

chris

Tbh, I doubt you will get a sniff off any of them. The 9E footprint is currently the strongest one out there at this location

Is your Ka band LNB polarised correctly ?

Test card only

20185
Left hand circular
25000
1/2
QPSK DVB-S2 MPEG-4
1101/1201/1101


_http://www.satbeams.com/search-137?ordering=newest&searchphrase=all&searchword=Ka+band

 

[Vipersan]

thanks for that Chris
I'm assuming you mean there used to be ..or should be a testcard on rhc /v from ka sat 9E ?

switching between polarities produces the same spectrum regardless ..
I am also assuming the lnb is mounted with the F connctors pointing straight down ...not that it should make any difference to circular...
Its hard to believe inverto make this beast but it isn't even listed at their site ....so no info available
How on earth can you distinguish between the two polarities ...unless they are switched with 14/18v ...or even 22khz on/off ..
tried all variations but the spectrum just looks the same..
I'm baffled to say the least..
rgds
VS

 

[Topper]

May be a red herring this VS but I have a vague recollection that back in the days of BSB (that became Thor) they used to use current switched polarity as I remember, someone else may confirm or deny.
Or is my memory failing completely

 

[Vipersan]

May be a red herring this VS but I have a vague recollection that back in the days of BSB (that became Thor) they used to use current switched polarity as I remember, someone else may confirm or deny

You may be right Topper ...but it would be a bit like re-inventing the wheel.
...and would make this lnb totally incompatible with all other sat receivers and freesat boxes ..
A very bad move ..so I think more likely 14/18v switching to comply with freesat boxes already on the market
Or you'd have a lot of very angry Irishmen baying for your blood..
just a thought ...but then ..a custom box would be an excuse to make more coin I guess..
why o why did inverto not provide any info with this thing..beggars belief
;)
VS

 

[Vipersan]

Currently aimed at 9E ka sat
Well ...at least I'm up and running ..sort of ..
Managed to locate 3 data transponders on vertical (RHC) booming in at between 8 and 13.5 db ...
Not scanned LHC yet ..
Also what I suspect was the 'testcard' transponder ...but too low at 4 db ..so couldn't get a lock ..but I'll keep trying ..
I'm sure I'd do better if this lnb had a pf scalar feed ..
Does such a thing exist for ka ?
Answers on the back of a postage stamp ...as we might as well keep things to scale ..
We are talking ...small..
;)
rgds
VS

 

[Chris76]

Great news vipersan

to answer one of your question i can skew the lnb 360° and it makes no difference at all. Also the fec will work on 1/2 and also 7/8 and the roll off makes no difference as i can use both also.

Currently aimed at 9E ka sat
Well ...at least I'm up and running ..sort of ..
Managed to locate 3 data transponders on vertical (RHC) booming in at between 8 and 13.5 db ...
Not scanned LHC yet ..
Also what I suspect was the 'testcard' transponder ...but too low at 4 db ..so couldn't get a lock ..but I'll keep trying ..
I'm sure I'd do better if this lnb had a pf scalar feed ..
Does such a thing exist for ka ?
Answers on the back of a postage stamp ...as we might as well keep things to scale ..
We are talking ...small..
;)
rgds
VS

 

[Vipersan]

Great news vipersan

to answer one of your question i can skew the lnb 360° and it makes no difference at all. Also the fec will work on 1/2 and also 7/8 and the roll off makes no difference as i can use both also.

I suspected as much Chris ..re the skew ..it being circular there is no correct skew setting ..
Thanks tho for the info re FEC settings ..
Sadly getting nothing at what I would assume to be Saorsats transponder frequency ..
As expected (location Manchester)

Im using LO setting 18750
22khz off

LHC (H)

Saorsat :-TP 20185
SR 25000

everything else Auto

Not even a hint of a signal ...so it looks like the fringe drop-off is very rapid at the edges of the footprint ..
I guess Saorsat can claim success in this regard..
No fun for Dxers tho'
;)
rgds
VS

 

[Channel Hopper]

Not even a hint of a signal ...so it looks like the fringe drop-off is very rapid at the edges of the footprint ..
I guess Saorsat can claim success in this regard..
No fun for Dxers tho'

I would have thought the opposite 'Never give up, never surrender!'

What is the Inverto LNB model you have ?

 

[excollier]

Apogee on an Irish website used
10765v 27500 1/2 13v
22khz off.
Perhaps if you try that, but I think you are right, the fall off is very steep.

Sent from my HTC Tattoo using Tapatalk

 

[Vipersan]

I would have thought the opposite 'Never give up, never surrender!'

What is the Inverto LNB model you have ?

Sad to say there isn't actually a model number or Type no on the lnb or the box ..
Its simply listed as 'Inverto White Twin Ka Band LNB Circular Dual Polarity '

Ebay item :-
190636198893

If you want to check it out CH
rgds
VS

 

[Chris76]

Use the 10764 tp and see what you get vipersan. it is 100miles but with a dish that size you should get a sniff...there is an op in wales getting it ok also for a reason i don't fully understand i can lock onto this tp with as little as 18% snr and20% agc so there is hope.


Chris

 

[PaulR]

May be a red herring this VS but I have a vague recollection that back in the days of BSB (that became Thor) they used to use current switched polarity as I remember, someone else may confirm or deny.

I'm fairly sure that they dodged the problem by using only one polarity. ISTR articles in Wotsat and the like about reversing the polarity (Doctor) by dismantling a Squarial and rebuilding it by rotating an internal sheet 180 degrees about.

Or is my memory failing completely

You and me both...

 

[Channel Hopper]

Im using LO setting 18750

From your ebay listing


19.7-20.2 Ghz
(Lo 21.20 Ghz)

Like C -Band, the final output will be an inversion, or the processing of the transport stream will be rejected at the demodulator stage.

 

[timo_w2s]

I'm fairly sure that they dodged the problem by using only one polarity. ISTR articles in Wotsat and the like about reversing the polarity (Doctor) by dismantling a Squarial and rebuilding it by rotating an internal sheet 180 degrees about.

Yes, the BSB channels only used one polarity and the dishes and squarials had no way of switching (other than physical hacks as you mention). I guess it kept things more simple and costs down.