Reply With Quoteeddies157 (26-08-16),hazman (24-08-16),Indigo (24-08-16),LeroyPatrol (24-08-16),Mr 672A (24-08-16),mtv (23-08-16),Saintaholic (25-08-16),Thala Dan (23-08-16),tmsani (24-08-16)
C-Band LNB's Scalar Rings and dishes
In view of the challenges in reception of Asiasat 5 I thought it would be a good idea to start a new thread specifically dealing with C band LNB's and related hardware. Since the change from GasFet to HEMT back in the early nineties, there has been little or no major breakthrough in LNB performance. and so I have lined up a few and did the test on TVE.
From left being average to the right top performer all tested on same 2.3 dish using Xcruiser box the Zinwell 73, The little Mediastar flickering between 73 and 74 the Titanium at 74 and the Gospell topped it at 75% quality. The Titanium was a recent purchase and regrettably disappointing considering the $140 spend on the 2 units.. The Aluminum finds are just a gimmick.
Feed Horn does play a major roll and add 1 to 1.5dB to the dish performance. If anybody can get their hands on below Feed Horn you are on a winner. Alternatively try and source an ADL Feed
Last edited by B52; 23-08-16 at 10:58 PM.
eddies157 (26-08-16),hazman (24-08-16),Indigo (24-08-16),LeroyPatrol (24-08-16),Mr 672A (24-08-16),mtv (23-08-16),Saintaholic (25-08-16),Thala Dan (23-08-16),tmsani (24-08-16)
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Interesting comparison, although no industry standard measurements used, a good effort on your part.
One small point, none of the pics show an LNB with separate feedhorn, they are all integrated LNBF's.
An example of a feedhorn (which a separate LNB mounts to)
hazman (24-08-16)
Interesting comparison. Did you use same feed horn for all the LNB's in the test? Where did you get these oversized feed horn i am finding it difficult to get itOriginally Posted by B52
Location: Sunny Perth
It appears, you (and some others) do not understand what a feedhorn is.
A feedhorn is a separate item from an LNB.
When you have an integrated LNB and a feedhorn, it is known as an LNBF.
In the case of typical domestic type LNBF's, many just refer to them as an LNB, but this is technically incorrect.
As I mentioned above, ALL of the pics the OP displayed are of LNBF's, therefore, he has not tested any 'feedhorn' as such.
All his comparisons are between LNBF's.
To clarify, here are some pics of feedhorns.
As you will notice, none of these feedhorns have an LNB attached.
Here are some examples of LNB's
And here are some LNBF's (feedhorn and LNB integrated)
Examples of a scalar ring (which confines the 'view' of the feedhorn to the surface of the dish)
Hope this clarifies the differences.
FTTP (24-08-16),gulliver (25-08-16),LeroyPatrol (24-08-16),Thala Dan (25-08-16),tristen (25-08-16)
What is the purpose of the fins on the Titanium Lnb?
In this case, I suspect just a visual gimmick to increase the cost.
Fins are typically used in/on devices to dissipate heat, eg: heatsink, which is what the manufacturer claims, to lower temperature and increase performance.
I very much doubt it helps much at all, in fact, it's likely to even increase heat, having a larger surface area exposed to direct sunlight.
If having fins like this were so beneficial, every LNB/F manufacturer would be using them.
CONAXLE (24-08-16)
Great Post, I just learnt more in five secs of reading here than the last 5 years...
Thanks mtv, I thought as far as lowering the temperature of the lnb, It will protect your transponder signal from IR or WiFi interference...
Temperature variation can cause drift of the oscillator frequency, which is where a PLL design helps, but minimising interference can be done mostly by filtering and to a lesser degree, dish placement. eg: shielding from interfering signals behind and to the sides of the dish.
Same dish and feed horn used. I got that oversized feed horn about 8 years ago from Mediastar in Sydney. Last check they don't have them anymore.
What feedhorn are you referring to?
None of your pics in this thread show a feedhorn???
I think he is talking about the feedhorn in this picture MTV
[/QUOTE]
Last edited by B52; 25-08-16 at 04:17 PM.
OK... that's a scalar ring... not a feedhorn.
What you have there is an LNBF mounted on a scalar ring.
I am sure I read that the rings or Fins inside the Feedhorn were designed/intended to minimise (Unwanted/Out of Phase) reflections from the surface of the dish and helped to guide the required signal into the LNB.
Having absolutely NO knowledge on the subject I took it as correct but I did wonder how it could block one and not another when you consider the range of the signal coming in?
I stand unequivicably behind everything I say, I just dont ever remember saying it !!
This thread reminds me of some past threads where it was evident that there was (and apparently still is) much confusion regarding the use of terminology when discussing LNB's etc.
For those who are interested, there is quite a good (non-technical) discussion regarding LNB's feeds etc., LNB mysteries explained, at the Satcure website (). Please note that the discussion refers specifically to Ku-band, but the principles are just as relevant for C-band also.
For additional reading, I have uploaded a copy of the AFRTSŪ Defense Media Center Satellite Handbook to .
The section relevant to this thread is in section 4.4 beginning at page 33.
The whole of the publication is worth reading as it gives a good outline regarding satellite signal reception, but with particular emphasis to the AFRTS (Armed Forces Radio & Television Service (US DoD)) broadcasts via satellite.
Other good sites for similar information are California Amplifier (calamp.com), Norsat (norsat.com) and ADL (), all reputable manufacturers of LNA's/LNB's, feeds and other associated equipment.
There really is no compensation for just using a bigger dish. Here you can see mounted feehorn and microwave filters and LNB's at top.
IF EVOLUTION WORKS, WHY SO MANY IDIOTS?
1.8m on KU band Twin LNB setup for 128E Sky Perfect.
IF EVOLUTION WORKS, WHY SO MANY IDIOTS?
oh baby.....feed horn porn. Haven't had a thread like this for ages!
.........Leroy
XCRUISER HDSR600HD twin sat and terrestrial receiver $OOS *
XCRUISER HDSR385 Avant - sold out$OOS UltraPlus DVB-T and DVB-S2 tuners $49 Remotes $OOS
Back to the future.
Loving it!
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