..and so it begins ..

[Captain Jack]

I am probably talking out of my arse but can you not open the LNB housing and see what frequency crystals are?

 

[Vipersan]

Indeed CJ ..such an operation might help ..but my second sacrificial SL3 hasn't arrived yet ..and I don't want to damage the one I currently have working.
rgds

 

[Analoguesat]

Yup 2F Ka band payload would seem to be a likely candidate.

I'll see if I can get any info out of the SES facebook page. You never know.

 

[Llew]

The Dishworld.de forum (KA Band section) shows two frequencies found on 2F 28.2 in July.

19745 SR 57000 Continous Stream

21750 SR 60000

Wow, they're mega SRs

Don't know if they're still active.

 

[hvdh]

The LO reportedly (as Vipersan also noted in this thread) should be 18050 MHz.
19700...20200 MHz converts to 1650...2150 MHz
18300...18800 MHz converts to 250...750 MHz, or with the extra 2400 MHz mixer to 2150...1650 MHz. That means effectively a LO of 20450 MHz.
These LO's and ranges can simply be entered in Crazyscan here (after choosing Ka-band or Ka-band Inverto).
Maybe I missed the point, but what is the problem really, is the LO different?

 

[Vipersan]

The LO reportedly (as Vipersan also noted in this thread) should be 18050 MHz.
19700...20200 MHz converts to 1650...2150 MHz
18300...18800 MHz converts to 250...750 MHz, or with the extra 2400 MHz mixer to 2150...1650 MHz. That means effectively a LO of 20450 MHz.
These LO's and ranges can simply be entered in Crazyscan here (after choosing Ka-band or Ka-band Inverto).
Maybe I missed the point, but what is the problem really, is the LO different?

The SL3 is effectively 3 lnbs in one case ..so I simply wasn't sure of the LO frequencies of the Left and right LOs accuracy and therefore the accuracy of the displayed scale by crazyscan after conversion by the SUP-2400.

We are assuming 18050 IS correct ..but I personally can't confirm this..

What you have said sounds about right tho' ..
I simply would like to have found one reported identifiable frequency to check this accuracy ..and so far had been unlucky.
Cheers
VS

 

[hvdh]

Check Lyngsat Astra 1L, 18359H and 18366V should still be active.

Also 18411 MHz should have a data carrier: http://forum.dxtv.de/wbb/thread.php?threadid=20931

Your "comet constellation" on 11787 MHz, I'm not sure what LO setting you were using there?
If it was 9750 MHz, then the IF was 2037 MHz, so 20450 - 2037 = 18413 MHz.

If for the time being, you would select "L-band" LNB in Crazyscan, calculations would be a little easier!

You may check my list for other Ka-band capable satellites:
http://members.ziggo.nl/hvdh16/Sats/Sats.htm

 

[Vipersan]

Ok ..a slight detour ..
Having read a recent post on digital spy of which our Remlap was a contributor.
A guy in Stoke reportedly was getting Saorsat with a very expensive marine lnb from the USA.
So off came the SL3 ..and on went the inverto Soarsat dual.
I figured it worth another go ...and no I haven't locked Saorsat..
Even though I amas far inland Eastward as the guy in Stoke..
The difference ..I am further North ..
..and so am likely to be subject to interfering spots ...particularly the Scottish spot ..which I have gone on about at some length in the past.

I referrd to it as the blank carrier ..or jamming carrier..
Well it's still there ..but looks to have changed.
I removed the Invertos white cap for a tiny bit more gain..and mounted it.
Then did a scan..
The screen grab is attached.
Saorsat is QPSK or so Lyngsat reports..and I can no longer lock anything at all ..
Not surprising really ..as the constellation clearly shows not only the Saorsat QPSK signal ..but a fainter 16PSK signal underneath.
See for yourselves ..
Comments welcomed..
rgds
VS

 

[Vipersan]

Oh ..and I took the time to examine the inverto conical feed as well ..and at the bottom of the waveguide is as expected ...a stepped septum feed RCHP/LCHP signal seperation plate.
This certainly appears to be the way these circular lnbs operate ..as the SL3 uses a similar method .
rgds
VS

 

[Vipersan]

Ok ..working on the perhaps insane assumption that the so called blocking carrier is now 16PSK ..but on the same frequency as Saorsat.
I figured what if that could actually be advantageous ?
So hooked up the inverto to the F15 ..which is a tiny bit higher gain thanthe TBS card BUT ..has the advantage that it would hopefully ignore 16PSK signals ..
Well ..I still cant get Saorsat ..but have managed to at least recognise Saorsat again ..
But signal is just too low.
I'll try again on a less cloudy day ..with less rain in the air ..and without the invertos white cap re-fitted..
Time to go to work ..
bbl
VS

 

[Vipersan]

FWIW ..
I've been very closely monitoring the signal level at my location in the firm belief that Saorsat _may_ be a very brief possibility ..at certain times of the day.
This is based on the what I now believe to be the scottish beam tansmitting on the same frequency being modulated in 16PSK and that the F15 could never respond recognise and lock this..
So would hopefully reject it.
Absolute peak of what I perceive to be the Saorsat signal ...NEVER reaches the magic 3db which equates to roughly 30% ..which I understand to be the minimal lock requirement..according to what I've read elsewhere.
Max fringe wobble ..peak signal is 2.6 db (26% ) at exactly 16:47 PM ..and very quickly fades after this time.

I honestly believe if I could get say ..another 0.5db at 6:45PM I could achieve a brief lock.
Ok ..it would NEVER be a useable signal ..but all I want to do is prove the point.
Anyone with an F15 and an inverto Saorsat lnb at the focus of a 1.2 mtr dish either 30 to 50 miles west or 30 to 50 miles South of my location could prove this theory.

Previously I had much higher signal levels 5 - 6db plus ..and never achieved lock ..but it's my firm belief that both Saorsat AND the scottish beam were both useing QPSK at this time ....not like now.
rgds
VS

 

[Vipersan]

Check Lyngsat Astra 1L, 18359H and 18366V should still be active.

Also 18411 MHz should have a data carrier: http://forum.dxtv.de/wbb/thread.php?threadid=20931

Your "comet constellation" on 11787 MHz, I'm not sure what LO setting you were using there?
If it was 9750 MHz, then the IF was 2037 MHz, so 20450 - 2037 = 18413 MHz.

If for the time being, you would select "L-band" LNB in Crazyscan, calculations would be a little easier!

You may check my list for other Ka-band capable satellites:
http://members.ziggo.nl/hvdh16/Sats/Sats.htm

Excellent list buddy ..I've bookmarked it for future reference,
Cheers
VS

 

[Vipersan]

Oh ..forgot to add that the white plastic cap on the inverto Saorsat LNB ...reduces signal by approx 0.5db ..
Fitted = 1.6 > 1.7db variable
Removed 2.0 > 2.1 db variable

 

[Vipersan]

Now this is where YOU get involved ..
Comments ..theories..suggestions etc..
The Sacrificial SL3 has been opened up and the Left lnb workings uncovered..
See pics for details.
Remember there are 2 identical Ka lnbs in the unit..
Left and right either side of a Ku..
All 3 lnbs are designed for circular reception..
Both of the Ka lnbs can receive either Ka low or Ka high bands..Left OR right circular..
At this stage Im after operational theory..with a view to possibly converting the circular function to linear if possible.

I'd like your input ..as to theory of operation of this complex triple lnb ..and suggestions regarding conversion..
For example ..would removing the septum feed be sufficient ?
would this then allow the left and right linear signals to navigate to their respective probes..once the lnb is orientated correctly on the dish ???
rgds
VS

 

[Vipersan]

..and here is the SL3 fully naked ...
nothing was damaged during the disassembly so could easily be rebuilt ..
Note the 3 big beefy transistors ..
4 f connector outs ..each replicating the same signal but isolated to drive multiple receivers in a typical US home..
No wonder these lnbs draw a heavy current ..
If/When I reassemble this lump ..3 of these transistors will be left disconnected..
Single channel out only required by me..

 

[Vipersan]

Waveguide aperture measured at the point closest to the pcb ..
diameter = 11.5 mm ..and from memory pipe used for connecting up gas fires was 12mm internal diameter ..so some of this should serve to make experimental feeds..
Just a thought...

 

[pride21]

hi VS i have been having a go at ka got a inverto ka lnb tried 9E i knew i would not get the transponder for the irish channels but did a scan on the TM as you know the lo is 21200 if i put that in the receiver it scans between 22000 and 23000 and the scanned frequency was 22117R 25000,so i worked out that if you put in the lo at 19170 the scanned frequency worked out at 20188R 25000 its the same as the Saorsat signal but right hand,tried horizontal nothing,i also tried Hylas at 33.5W got 20385H 8332 both signals must be data.

 

[Vipersan]

hi VS i have been having a go at ka got a inverto ka lnb tried 9E i knew i would not get the transponder for the irish channels but did a scan on the TM as you know the lo is 21200 if i put that in the receiver it scans between 22000 and 23000 and the scanned frequency was 22117R 25000,so i worked out that if you put in the lo at 19170 the scanned frequency worked out at 20188R 25000 its the same as the Saorsat signal but right hand,tried horizontal nothing,i also tried Hylas at 33.5W got 20385H 8332 both signals must be data.

Yep ..nothing from Hylas other than data signals AOL etc...but they are mighty strong so should be easily receiveable.
Quite a few are SR 45000 ..so can be identified with this ..
A TBS card or similar is useful for identification of course.

 

[Vipersan]

..Well the sacrifice was made ..Lopped off the tripple feed from the second SL3 ..with a view to filing out what repains of the septum on the right hand ka lnb ..then start experimenting with the fitting of a linear tube feed such as the xmw..
Maybe this is really stupid ..but hey ..thats wot experiments are all about right ?

 

[Vipersan]

So maybe this will work ..maybe it wont ...
put some cuts in the outer stubs of the remnants of the feed horns ..
These provide a key for the liquid platic potting mix..
Then cut the top of a fibre glass resin tin ..and used as a surround ..embedded in plasticine ..and poured a mix of liquid plastic until level with the lnb beed stub ends..
This will hopefully provide a raised flat platform to attach test feeds to ..
You will also notice the remains of the septum feed in one of the Ka lnb waveguides is now gone ..with minimal damage to the cast surface inside..
rgds
VS