Worth an ask ? Hughes feed needed.

[Vipersan]

Sadly the hughes lnb I bought and paid for from the USA in April never materialised ..
No way to track it down and no one took responsibility for it's loss ...I therefore had to swallow the loss ..and yes it pissed me off..
But I still need another one...but not the whole lnb/odu..
Just the feed..
Ringed in yellow on the attached image..
Worth an ask if anyone out there has one they want to sell at a reasonable price..
You may have bought the whole assembly and it's just sitting on a shelf gathering dust..
perhaps you'd like to recoup some of your outlay ?
Posting just the feed would cost considerably less than the whole ODU.
Like I said ..worth an ask ?
Otherwise I'll just keep watching ebay for one to turn up ...
rgds
VS

 

[Llew]

You can have mine VS (doesn't have bracket shown in your pic though - is that necessary?) It doesn't do anything for me on the Triax dishes, and I don't really want to use it on the Gibby. Happy enough with the feed from the Saorsat LNB.

PM me with your address.

 

[Vipersan]

You can have mine VS (doesn't have bracket shown in your pic though - is that necessary?) It doesn't do anything for me on the Triax dishes, and I don't really want to use it on the Gibby. Happy enough with the feed from the Saorsat LNB.

PM me with your address.

Are you sure Llew ??
I'm hoping for a better match for the SL3 ...since the other works so well on the XMW ..
How much for it buddy ?
rgds
VS

 

[Llew]

What it came with (LNB, depolariser) much more useful to me. Just lying idle, hence gratis to you VS.

 

[Vipersan]

I owe you one buddy ...
IF the one I bought ever finds it's way here ..I'll happily pass it on to you..
cheers

 

[Vipersan]

Cheers Llew ..
arrived with this mornings post ..
scraped out what was left of the transparent window and epoxy seal ..
Just completed the fitting of another cut down plastic bottle and potted up with liquid plastic..
Hoping to fit a new window of polycarbonate later this evening ...though depends how quickly the potting plastic cures.
Cheers again buddy..
much appreciated.
VS

 

[Llew]

Blimey! Sent, received, potted up and nearly ready to fit in a day and a half

Good going VS, let us know of your results with it.

 

[Vipersan]

Yep ...
and here it is with it's new window ..
lol
;)

 

[Llew]

Looks good to go. Lovely job VS.

 

[Vipersan]

Looks like this feed is not suited to the SL3 ..as believe it or not it is actually behaving as though polarity specific in Ka band A...
Also the overall gain is less than the modified inverto feed..
Maybe just behaving as a filter it being specifically designed for higher frequencies..
It's orientation (being elliptical) is very relevant ..
Placed vertically ,,,ie longest width of the oval up/down ..it almost completely nulls out a Vertical scan on the SL3 ...allowing mostly Horizontal only..??
if the orientation is changed to horizontal ...then mostly allowing a vertical scan at the expense of Horizontal ??
There is no septum in the feed so I was very surprised at this result ...but it may well be advantageous on the Norsat 9000AF ..
This is yet to be tried ..
In short I believe this feed is highly tuned ..
Most likely due to the oval shape and number of concentric rings...
Can't win 'em all but looks like the inverto is more suitable for the SL3 ..for now at least..
I shall be on the lookout for one closer tuned to Ka Band A.
rgds
VS

 

[Llew]

Well I tried it on the Norsat and XMW LNB, and on the original Hughes assembly on the Triax TD88, and it struggled to find anything worthwhile on any transponders, whichever way it was orientated. 19E Hor. Teleippica was the best I was able to receive with it on the Norsat, but that's an easy one here.

For me, the Inverto feed is as good and sometimes better than the FD9000 feedhorn. Just waiting until I accidentally destroy the Triax Ka LNB with my experiments, then I'll part the feed from it...

 

[Vipersan]

Totally agree Llew..
The Inverto is an exceptional feed ...and is of course designed for circular reception in Ka band B ..
But appears very broadband in that it works well in Ka A and Ka D as well ..
It may well be that the more concentric rings the 'horn' has the more 'tuned' it is ...thus frequency specific..
Which then begs the question ..'why the hughes feed outperforms my inverto in Ka D on the XMW ...but underperforms the inverto in Ka A ...?'
Maybe I just got lucky and it's a good match for the Fortec Star 1.5 ..
Thus the added illumination compensates for the reduced gain compared to the inverto..
Somewhere in there is the answer ..but have yet to find it..
We just gotta keep tryin' stuff is all ..
Experiment is everything when dealing with the unknown.
rgds
VS

 

[Llew]

I never checked the exact dimensions of the Hughes' feedhorn tube. Is it exactly the same as the Inverto's? Considering that the Hughes has to transmit at a higher frequency as well, maybe there's a compromise there for reception and transmission?

 

[Terryl]

Would this do you any good??? Had this out in the back barn.

 

[Vipersan]

What frequency is the lnb Terry ??
If in the region of 17 to 19 ghz ...
then yes the feed and lnb would be of great interest ..not so much the transmitter lump..at the bottom..
Everything else though ..certainly.


Any chance of a close up of the lnb label Terry ?
rgds
VS

 

[Terryl]

It looks to be from an old Starband internet system, I will try for some closeup's of the small module, here is it's model number, Gilat MODEL NJR2544HWN, if that helps.

 

[Vipersan]

Cheers Terry ...but looking like the unit you have is actually Ku band ...
Did a search using the Gilat info you provided and found this linked to Ricks..

http://rickcaylor.websitetoolbox.com/post/gilat-lnb-5418617

Oh well ...it was always a longshot ..
rgds
VS

 

[Terryl]

OK thats cool, I haven't seen this thing for about 5 years.

And remember that a waveguide at 10 GHz at a full wavelength will work as a 1/2 wavelength at 20 GHz, or a 1/4 wavelength at 40.

It's just a bit harder to match up.