Inverto LNB`s are good!

***CROSSBONES*** · 29-09-2006

I have just installed a inverto C120 lnb on my Gegorian 1.2m dish, and am now pulling in some of the viasat 5*E channels.

The weather has been bad the last few days, so cant really test it properly.

I couldnt touch these channels with my invacom lnb!

I think my dish is a little out, so when the wheather gets better ill have a little play.

Here are a few pics.......

***johnsattuk*** · 30-09-2006

Although some have not had such good results with the Inverto's, generally they do seem to do well on the gregorian dishes.

***iwol*** · 30-09-2006

hi where did u get it from and what price thanks

Likvid · 30-09-2006

As i said months earlier the Inverto C120 is the "wunder" LNB for the Gregorian dishes, mostly due to some perfect phasing of the waveguide for this kind of antenna.

***Rob*** · 30-09-2006

And it's also a "wunder" LNB for my prime-focus dish, wouldn't be without it.
I had a good C120 LNB before but with the Inverto White Tech my signal quality reading went up 3 to 7% on all channels.

Gungadin · 30-09-2006

Bought one of these c120 Inverto's as a cheap stand in (£15 new off Ebay

) for a 90cm "Precision Antennas" prime focus I was resurrecting... The "resurrection" is finished and in working condition with great results! so will be leaving on there.

***CROSSBONES*** · 30-09-2006

* iwol

I had them from wizard on e-bay bought with best offer I had 2 at 13quid.

One for mr c/master 1.8m for when I install it.

***iwol*** · 30-09-2006

hi are they ok nfor a channel master offset as it states for a prime focus on the wizard site thanks

***2cvbloke*** · 30-09-2006

Not had a chance to test mine, but it's nicely fitted into my Attisat FPA (with some modifications to the Attisat) due to it's compact size, and it's so cheap it's too hard to pass up...

30-09-2006

Told you they are good lnb's the only bad thing for me is i cannot get them trade any more,

***CROSSBONES*** · 01-10-2006

iwol, If you use the feed horn, Then it will be a great match.

**femto** · 02-10-2006

I just bought a 40mm Inverto Silver Tech to go on my soon to be installed Gibby 1m. It arrived before the new dish so I thought I'd see what difference in signal level I got on an old 60cm ex-Sky Analogue dish which is pointed at Hotbird.

I have an old ALPS BSNE8 on the 60cm usually and I get signal levels in the 78-81% area.

I substituted it with the Inverto and was most disappointed. Signals dropped to some horrendously dire level somewhere in the low 50s!

*Fast-Forward 1 week ahead*

So I was out in the garden, setting up the angles on the Gibertini polar mount on a plumb ground pole and once I'd got it set up on the arc using the ALPS, I thought I'd try the Inverto again.

Wow. Very much improved over the ALPS. I was getting 15% more signal.

Go figure!

**izefisherman** · 03-10-2006

Time to add some partly negative feedback to this thread. Again not enough specimens involved to produce any hard facts but anyway:

Target: Astra 2D, Astra 2B southbeam

Receiver: DM500S with ALPS tuner. 78% SNR needed for stable picture * FEC 5/6. The limit for 2/3 FEC is 74-75% SNR. This tuner generally shows much higher SNR values compared to my DM7020S with Philips tuner but the treshold for stable picture is also much higher.

Dish: Aerial 180cm primefocus with original feedhorn.
http://www.aerial.fi/ep/tiedostot/Sa...V_antennas.pdf

LNB 1: Invacom SNF-031 0.3dB NF
http://www.invacom.com/documents/Single_002.pdf

LNB 2 & 3: Inverto IDLP-SFLANGE 0.3dB NF
http://www.inverto.tv/ProductsPage.asp?ProductID=93
on the website they claim 0.4dB NF

LNB 1 has been in use for approximately 8 months on this dish and delivered the following results at the time of testing:

2D, 10773 H 22000 5/6, BBC News 24: 81% SNR

2D, 10876 V 22000 5/6, Sky Travel: 77% SNR

2Bs, 11973 V 27500 2/3, Zee Music: 80% SNR

2Bs, 12207 V, 27500 2/3, Sky News: 78% SNR

LNB 2:

2D, 10773 H 22000 5/6, BBC News 24: 77% SNR

2D, 10876 V 22000 5/6, Sky Travel: 77% SNR

2Bs, 11973 V 27500 2/3, Zee Music: 82% SNR

2Bs, 12207 V, 27500 2/3, Sky News: 80% SNR

LNB 3:

2D, 10773 H 22000 5/6, BBC News 24: 77% SNR

2D, 10876 V 22000 5/6, Sky Travel: 79% SNR

2Bs, 11973 V 27500 2/3, Zee Music: 81% SNR

2Bs, 12207 V, 27500 2/3, Sky News: 80% SNR

The Inverto LNB's were equal or better at Astra 2D vertical signals compared to the Inva. An interesting fact is that the vertical probe is behind the horizontal probe in the Inverto LNB's but the Inva has the Horizontal probe behind the vertical seen from the C-120 flange.

In the middle of strong North beam signals close by the Inverto did a good job digging out the weak southbeams in between, I expected the Inva with much better claimed phase-noise parameters to win this part of the game but clearly not so.

Why both Inverto's failed to deliver horizontal reception of the Astra 2D transponders remain a mystery. Both are useless for that purpose in my current setup. Here the Inva came out as a clear winner.

Likvid & co. could comment on this. Is it possible that the signals need to travel a certain distance in the waveguide to have a better phase? Clearly the polarity that had to travel the longer distance to reach the probe was received better in the Astra 2D case.

I will continue testing another day, let's see what a 90 deg shift in LNB orientation brings. Sadly I don't have any C-120 extension pieces for experimenting with different waveguide lengths. Any idea where I can obtain these?

Ize

***iwol*** · 03-10-2006

thanks will wait the outcome

**izefisherman** · 04-10-2006

Tested LNB 3 in 90deg rotated mode ie. H becomes V and vice versa.

The test was carried out briefly:

0 deg rotation Astra 2D H-pol: 78% SNR
90 deg rotation Astra 2D H-pol: 80-81% SNR

Compared to yesterday's test the better Inverto turned 90deg is still 1% SNR behind the Inva. (77 vs. 81 and 78 vs 80-81) for Astra 2D H-pol signals.

**femto** · 05-10-2006

Strange....on my Echostar, I get perfectly good, stable pictures with much less than 78%. Mind you, you do say that the threshold for stable reception on your 500S is high.

I wonder if other owners of Dreambox DM500S receivers have the same experience, needing a high SNR to get stable reception? Interesting.

**izefisherman** · 05-10-2006

The SNR value in % cannot be compared between different receivers or even similar receivers with different tuner models fitted, eg. old DM500S vs. new DM500S.

The only comparable value is true noise-marigin or signal-to-noise ratio expressed in dB. Furthermore it needs to be measured accurately. No consumer set top box I know of does this, Some Nokia models may be an exception but the accuracy they reach in this has not been stated to my knowledge.

**femto** · 05-10-2006

Yes that's a good point. I suppose they're more of a guide than anything else. Maybe the readout that the Dreambox gives is more realistic.

Let's put it this way: I've never seen the Signal Quality on my Echostar go above 90% and that's with a 1 metre dish pointed at Astra 1 from the UK!

Your LNB comparison is good as you were using the same equipment with both LNBs and getting different readings. Therefore there is a difference in the two LNBs.

I wonder... could it be the feedhorn you're using being more suited to one than the other or differences in the components used.....*or* differences in the physical positioning of the probes inside each LNB?

How would this affect the phasing of the signal when comparing H with V?

Is the F/D requirement the same for each LNB?

This kind of thing interests me - gets the old gears turning.

**izefisherman** · 05-10-2006

The dish / feed f/D should not affect the results since the feed/dish used is the same for every test. The phase center of the feed should also stay unaffected as long as the waveguide is long enough for waves to propagate inside it as intended. I am not 100% sure if it is and I hope to find some C-120 extension pieces for experimenting with this parameter. The feedhorn itself is a little different from the usual ones because it includes a section where the wave propagation most likely changes to multimode for a certain distance. The possible benefits from this arrangement are uncelar to me at present. The distance between LNB flange and the "chamber" in the feed is only 10mm and it could be that more distance is required here for some reasons. This feed design is from the times when you had either a polarizer or ortho mode transducer between the feed and LNB(s) and these would have contributed to the overall waveguide length. I have both of these types available but they introduce more unknown parameters to the test than I can handle so I'm really just looking for a straight piece of circular waveguide to add between feed and LNB

I will take some pictures of the parts involved next time I remove the feed.

**femto** · 05-10-2006

Yes I''d be interested in seeing those pictures. Experimentation, to me, is all part of the fun!

**olisun** · 11-11-2006

Originally Posted by CROSSBONES

I have just installed a inverto C120 lnb on my Gegorian 1.2m dish, and am now pulling in some of the viasat 5*E channels.

The weather has been bad the last few days, so cant really test it properly.

I couldnt touch these channels with my invacom lnb!

I think my dish is a little out, so when the wheather gets better ill have a little play.

Here are a few pics.......

Did you have to replace the feedhorn?

The previous owner has stuck the polorizer is stuck to the LNB by some glue, I don't know how to detach that... damn

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