Ka lnb ?

[dreamsat]

Do you do it with CrazyScan? I have found that with strong signals in the right band, there are reflections about 1 GHz down. With the band A LNB I only scan up to 17600 Ghz in the very lower band. Everything below is coincidence and cannot be evaluated correctly.

 

[Trust]

Do you do it with CrazyScan? I have found that with strong signals in the right band, there are reflections about 1 GHz down. With the band A LNB I only scan up to 17600 Ghz in the very lower band. Everything below is coincidence and cannot be evaluated correctly.

No , using my Clarktech 5000 hd+ receiver

 

[Trust]

Hello Trust,

I don't want to take away your hope, but I've been experimenting with this constellation for almost a whole year. I have never reached the performance of LNBs individually mounted on OMT port. It was missing up to 3 dB. I really tried everything. If you got better results I would be happy. However, you should always carry out the test with the individual LNB on the OMT.

It works, but there are deviations in performance compared to the individual LNB.

I wish you success

After a lot of tests I have to aggree , a second lnb at that OMT brings down the signal from 11.7 dB to 7.9 dB in my case .
The second port is closer to the waveguide , I made a adapter to attach the lnb at the same distance from the waveguide .
To my surprice , the lnb attached on that modded port is giving 0.3 dB more signal ( 11.9 - 12.0 dB ) fluctuating
Back to the original port , ( 11.4 - 11.7 dB )



All the tests are done at 19.2 º E , then I moved to 42º E with still the drilled-out polaraiser between lnb and feedhorn .
Very weak signal , so I removed the feedhorn cover and put a plastic plate in the horn .
Nothing calculated just a blind guess ,only the diameter was depending .
To fit tight 9.4 mm at the beginning till 11 mm at the end , 37 mm long 1.6 mm thick .
Receiving Turksat Promo with 13.9 - 14.0 dB .
After changing the drilled-out polaraiser for a original polaraiser and another feedhorn with cover also 13.9 but 14.0 dB was not possible to reach .
Maybe the cover is guilty for that loss .

 

[zorrin]

After a lot of tests I have to aggree , a second lnb at that OMT brings down the signal from 11.7 dB to 7.9 dB in my case .
The second port is closer to the waveguide , I made a adapter to attach the lnb at the same distance from the waveguide .
To my surprice , the lnb attached on that modded port is giving 0.3 dB more signal ( 11.9 - 12.0 dB ) fluctuating
Back to the original port , ( 11.4 - 11.7 dB )

View attachment 142651

All the tests are done at 19.2 º E , then I moved to 42º E with still the drilled-out polaraiser between lnb and feedhorn .
Very weak signal , so I removed the feedhorn cover and put a plastic plate in the horn .
Nothing calculated just a blind guess ,only the diameter was depending .
To fit tight 9.4 mm at the beginning till 11 mm at the end , 37 mm long 1.6 mm thick .
Receiving Turksat Promo with 13.9 - 14.0 dB .
After changing the drilled-out polaraiser for a original polaraiser and another feedhorn with cover also 13.9 but 14.0 dB was not possible to reach .
Maybe the cover is guilty for that loss .

View attachment 142652

you mean you need a long guide to get a better signal?
You know why ?
Is it a question of wave hopping?

 

[Trust]

Zorrin , read from posting #84 in this topic

 

[zorrin]

Zorrin , read from posting #84 in this topic

when i said guide i meant the adapter.
My translation error...
Both, guide and adapter are therefore necessarily long for the propagation of the wave.
Or something like that.

 

[dreamsat]

After a lot of tests I have to aggree , a second lnb at that OMT brings down the signal from 11.7 dB to 7.9 dB in my case .
The second port is closer to the waveguide , I made a adapter to attach the lnb at the same distance from the waveguide .
To my surprice , the lnb attached on that modded port is giving 0.3 dB more signal ( 11.9 - 12.0 dB ) fluctuating
Back to the original port , ( 11.4 - 11.7 dB )

View attachment 142651

All the tests are done at 19.2 º E , then I moved to 42º E with still the drilled-out polaraiser between lnb and feedhorn .
Very weak signal , so I removed the feedhorn cover and put a plastic plate in the horn .
Nothing calculated just a blind guess ,only the diameter was depending .
To fit tight 9.4 mm at the beginning till 11 mm at the end , 37 mm long 1.6 mm thick .
Receiving Turksat Promo with 13.9 - 14.0 dB .
After changing the drilled-out polaraiser for a original polaraiser and another feedhorn with cover also 13.9 but 14.0 dB was not possible to reach .
Maybe the cover is guilty for that loss .

View attachment 142652

I also worked with these adapters and achieved the same findings. Only one waveguide output can be optimized at a time. The second then has losses. I even tried to add a third LNB to the back with a WR 42 Winke. This didn't work perfectly either.

 

[zorrin]

I also worked with these adapters and achieved the same findings. Only one waveguide output can be optimized at a time. The second then has losses. I even tried to add a third LNB to the back with a WR 42 Winke. This didn't work perfectly either.

It's a shame, the idea was brilliant and we all wanted that... I see that on the Tx part you had added a 90° waveguide.
I looked for plans for a Ka orthomode but they are still for Rx/Tx use with different frequencies in the Ka band.
I like your system with the 3 LNBs.

 

[dreamsat]

Schade, die Idee war genial und das wollten wir alle... Ich sehe, dass Sie im Tx-Teil einen 90°-Waveguide hinzugefügt haben.
Ich habe nach Plänen für einen Ka-Orthomode gesucht, aber sie sind immer noch für Rx/Tx-Nutzung mit unterschiedlichen Frequenzen im Ka-Band.
Mir gefällt dein System mit den 3 LNBs.

I saw an OMT from Patriot years ago. I couldn't buy it anywhere. But that was the only time. I think the application is really different due to the different frequencies and the filters for the internet applications.

 

[s-band]

I saw an OMT from Patriot years ago.

There is one in the middle of these photos:

KA Band LNBs - Satellites Community

Got them all, finally...

www.satellitescommunity.de

I have been looking for one as well, without success.

I have a Patriot 20/30GHz OMT but that's not much use for 20GHz on the WR28 port. Pic shows it with a WR42 guide attached.

 

[zorrin]

Today I made the "Gilat Longneck" and did some tests with a 1.2 CM at 7º E with my Clarke-tech 5000-C+
With the AN8004 at the original OMT RX port
21.633 H 9.5 dB 21.638 H 12.1 dB
at the TX port 7.9 dB / 10.4 dB
The AN 8002 is stil original and not tested
As you can see the feedhorn is far more close the dish for max signal .

View attachment 142483

Hi @Trust can you show what you hide under this tube please?

 

[Trust]

Hi @Trust can you show what you hide under this tube please?

View attachment 143152

the original polarizer

 

[zorrin]

the original polarizer

View attachment 143155

I'm going to start my tests again because I have better results without it...

 

[Trust]

Turksat at 42 gr has circulair signal

 

[John]

I'm going to start my tests again because I have better results without it...

The usual mux's that were on 42East Ka 18GHz Band A LHC have been gone for around two weeks or so since Turksat 5B started testing.
There have been Ka 18GHz Band A RHC markers seen but no programming as yet.
Also seen from 42East Ka at the moment are test signals on 19GHz Band B, 20GHz Band C i think and 21GHz Band D swapping between different polarities Linear and Circular.
Might be a while yet before there are some stable content of any kind.

 

[zorrin]

Turksat at 42 gr has circulair signal

A I understand better now.
In the text of the photo you spoke of tests on the 7°east which is in H/V.

 

[Trust]

A I understand better now.
In the text of the photo you spoke of tests on the 7°east which is in H/V.

I forgot to tell , I do have a original polariser for LHC and RHC and one that I drilled out and put a tube as straight waveguide in it for H and V .
Start reading from posting #84

 

[zorrin]

I forgot to tell , I do have a original polariser for LHC and RHC and one that I drilled out and put a tube as straight waveguide in it for H and V .
Start reading from posting #84

I also pierced one of my polarizer.
Did you have good results?
What is the inside diameter of the tube you inserted in it ?

For the moment I found that the feed horn alone gave me better results in H/V.

 

[Trust]

I also pierced one of my polarizer.
Did you have good results?
What is the inside diameter of the tube you inserted in it ?

For the moment I found that the feed horn alone gave me better results in H/V.

The tube is 9.5 mm inside , untill now I did not more tests as are mentioned in this topic .

 

[sat-tv-fan]

This Ka band LNB is somehow meant to work with a modification but how ?