As far as I know, the person in the Netherlands is modding the LNB's and converting them from 40mm to fit a C120 flange.Originally Posted by joshjess
As far as I know, the person in the Netherlands is modding the LNB's and converting them from 40mm to fit a C120 flange.
More fool them then, they are missing out on a potentially good market.
As far as I know, nobody is making mass production C120 LNB's for the general consumer/enthusiast market that use PLL technology. If Octagon got their act together and marketed some C120 LNB's based on PLL they could corner this market globally. They are already mass producing a PLL technology LNB in their 40mm offset twin output Octagon Optima LNB, how hard is it to tool up for C120?
Horse and water...
Rgds
Last edited by moonbase; 28-01-2013 at 05:05 PM.
I wish they would but take into account the consumer/enthusiast market is more of a Niche market now compared to around 15-25 years ago.
Sure the market has moved more from prime focus 20 years ago to offset focus today, however, Invacom and Inverto and other manufacturers are churning out C120 LNB's based on inferior DRO technology. Octagon are mass producing the Octagon Optima 40mm twin output LNB with PLL technology, if they tooled up to multi output C120 with PLL then they could potentially corner a global market within months.
Rgds
bit of a rare day today clear skies and i seen the sun , not seen that for a while.
so i had a chance to test the octagon lnb.
7 west. moddedtit , standard oco , modded octo.
jsc 42% 42% 42%
iraqui sports 55% 54% 55%
alsalam 54% 54% 55%
melody aflam 57% 47% 47%
trt 6 50% 47% 47%
kto 54% 34% 48%
10 east
al-alam 69% 61% 66%
ortc 67% 51% 66%
beladi tv 74% 64% 65%
ifilmi 68% 61% 66%
13 east
ad sport 96% 95% 99%
daystar tv 95% 97% 96%
id say its not bad at all with only one odd big signal drop on kto , really unsure why i tried 3 scans incase it had not fully locked onto the signal but no improvement at all
even when i modified it to bolt upto the cm feedhorn the signal was still 6% down so has to be something with that freq and the lnb not being very strong.
one other point the strongest signal on the meter was with the lnb moved maximum away from the dish and there is not really a great deal of movement so if i could have moved it further back it may have improved,so may well suite other dishes better in out of the box form.
13 east the strong signal again showed a improvement, but a waste of time in my view.
if you are looking for a new lnb i would say defiantly consider this one .
Hello cosworth4x4!
When you are comparing % with different LNBs is it Signal strength or signal quality?
If you connect any LNB to a Sat Meter and point LNB in a wall, it will already show a lot of signal strength, for example
- Inverto Black Pro 0.2 gives - 84% signal,
- Invacom SNH-031 shows - 81% signal.
When installed on a dish, Inverto will accordingly provide higher % of signal strength, but it will not give as good CN rate as Invacom, which probably shows that not all signal strength is useful, there is also noise in the signal. I think it would be more correct to compare CN, won't it?
I've had a chance to compare recently on my Channel Master 1.2 dish in Copenhagen pointed at Eutelsat 36E:
1. Inverto Black 0.2 C120 + CM feedhorn
2. Inverto Black Pro 0.2 40mm
3. SNH-031
4. SNF-031 +CM feedhorn
With the following observations:
- i get highest signal strength in the following sequence (starting with strongest): 2, 1, 4, 3
- I get highest CN ratio in the following sequence (starting with strongest): 4, 3, 2, 1
CM feed horn - na terelke.JPGCM feed horn 1.JPGCM feed horn 2.JPGCM feed horn 3.JPG
Last edited by Franky_D; 04-02-2013 at 02:59 PM.
i use the snr on the actual box , im not going to say its perfect but when my dish is so high up im working off the top 3 runs on the ladder to reach the lnb so least time i spend up there the better.
in one of the first tests i put the ber readings down as someone said use them instead of the signal strength,and to be honest they are meaningless to a lot of people including myself everyone understands a % figure .
is that a channel master feedhorn seen them with the eyebrow cover but never that shape before,face end looks a lot smaller than what ive seen before,can you measure the face.
one thing i have found what ever way you do youre testing there will always be someone say its wrong and do it another way but i guess thats life.
ive got measurements of gibertini and cm somewhere ill look for them and add later.
Last edited by cosworth4x4; 05-02-2013 at 07:49 PM.
her are the measurements of the channel master , see if they are the same as youres.
also a gibertini that is a bit bigger than a channel master one , not as stated in previous posts that its smaller.
Hi cosworth4x4,
When you test do you have your LNB vertical
with the dish.
I have a Inverto Black Ultra at (0.6w) and
can up Quality Sig by 10% on all Sats by
adjusting LNB Scew (5 Degrees) to the
east, (My rite as I look at dish).
Is there a (Sticky) showing people
what to set there (Scew) to, in the
form of a graph.
(1w = 6% east) and so on.
i set mine up with the meter , for each sat when testing the lnbs.
dont forget the dish angles as it turns ,to set up a happy medium , select the most central stored sat and use that for best skew adjustment.
i did have a website with a calculator on ill see if i can find it.
mine is skewed same direction , but no idea on the % its skewed at.
if you type /en/azel_calc.html into google it will be top of the list , cant post a direct link due to the rules.
Hi cosworth,
I once tuned a s@y zone (45cm) one mesh dish
to Intelsat 10.02 to pick up digi sport.
picked Up Intelsat with a signal of 32%.
The LNB was still set for s@y 28e, turned
LNB to just off vertical, Signal on
Humax HD2000 Uped to 63%.
A while back had 4 LNBs on a 1m dish
Not Motorised, Prime focus at 4.8e Siruis,
It used to open (TV1000) Films, Boxing,
the lot.
Black screen under 16% Sig Quality.
Best Sig in good weather was 26%.
When it rained (Black screen).
That was on the Humax 5400ip.
Bought a Invacom LNB,
Was viewing TV100 film's at
11pm in a snowstorm in December.
The Sat used to wobble in the evening
and the Signal would drop by 40%.
BF.
Hi cosworth4x4,
Thank's for en/azel.
BF.
Hi,
just remembered TV100 was on
the Pace D2MAX receiver, not
the Humax 5400ip.
BF.
a fixed dish will need a different skew for different sats , if you use that calculator try 1 west then 28.2 east , you should see the difference of skew required.
Nice pictures! I will try to make few pics with mesuments and post tonight.her are the measurements of the channel master , see if they are the same as youres.
also a gibertini that is a bit bigger than a channel master one , not as stated in previous posts that its smaller.
My feed horn is CM3040645 - an oldy, I think from those days when it was still CM making them. You can see similar ones on all original pictures of CM dishes.
I guess the one you've got was produced by Andrews or Raven (or whoever else owned the brand). So, there are two models. I would love to benchmark them between each other, keeping a eye on **** offerings.
Dish with feedhorn 1.jpgDish with feedhorn 2.jpg
I am pretty new with sattelite technologies and just need to get most out of my home dish setup, therefore looking into the details. I found this source very helpful in understanding what really matters: http://www.triax.fi/upload/how_to_se...stallation.pdf
I've come to understand (sorry for amateur level of conclusions):
- "signal strength" characterizes how much signal returns to the receiver from the LNB. It depends on cable length, build in amplifier of the LNB. If I connect LNB to a SatMeter and point into a wall I get 81% signal and (of course 0% quality), if installed on a dish then the signal strength will be somewhat higher (from 84 to 89% with different transponders). In my opinion if you want to use signal strength as any indicator, than only the part added to the signal when on the dish should be considered (i.e. 89-81%=8%, consider that part of this is still noise)
- "signal strength" is comprised of useful signal and noise, therefore overall signal strength is not an indicator
- BER is mostly important when setting the skew.
- Carrier to Noise ratio (CN) is more important to understand is the signal which you get is a good quality signal or mostly noise. In the Triax paper it suggests that it is mostly dependant on the size of the dish. In my experience it also depends on: a) using proper feedhorn (collecting signal from the dish to it's optimum); b) using correct skew; c) using quality LNB (that's where I guess cross polar isolation and local oscilator phase hoise are contributing) c) in case of 40mm LNBf - moving it closer or further away from the dish.
- the length of the cable is affecting the "signal strength", but not the CN. I get the same CN both on the dish and at home (50 meters of cable)
- in bad whether "signal strength" does not go down (no wonder - tuner-cable-LNB connection characteristis have not changed), it is CN which goes down. If it goes down to 7dB the picture starts freezing/crashing.
Look here what is CN and what it is affected by: http://books.google.dk/books?id=MM0d...0meter&f=false
Last edited by Franky_D; 06-02-2013 at 09:28 AM.
SatMeter and point into a wall I get 81% signal , but connect the lnb to a sat receiver and point to the wall you get 0%.
i assume the meter uses a different kind of meaurement , what happens if you point to a week sat ? or is the 81% youre getting just a reference reading?
regarding the channel master feed horn , i guess youres is a very old cm one, the one in the picture above on my dish is a channel master as it was bought before they got taken over , i always though this type that i am now using was a andrews/raven replacement .
if you find a big difference in size of the feedhorn ive got a spare i can send to you to try , but i will need it back.
You are right about difference between SatMeter and SatReceiver. I guess SatMeter readings are more honest, specially when it comes to signal quality. I remember Receiver showing quality higher than signal.. what can that mean!? :-/
I am attaching pictures with the same LNB a) connected on the kitchen table to a SatMeter and b) connected to SatMeter while on the dish. As you see signal strength is the same. With other transponders strength was 84% or 89%..
on the table.jpgpointed.jpg
The difference in size between the two feed horns is actually quite significant. Also there are no rings on mine. I would love to put the two to test! Will PM you shortly
DSC_0885.jpgDSC_0886.jpgDSC_0889.jpgDSC_0890.jpgDSC_0891.jpgDSC_0892.jpg
This Inverto Black C120 is soo tiny in real life! I was a bit disappointed with it's performance. It was worse than 40mm LNBf inverto black pro 0.2
Last edited by Franky_D; 07-02-2013 at 12:26 AM.
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