Cband signals are always changing

HBO

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Cband signals are always changing. The area where I live often experiences satellite signals fluctuating from +- 3DB from 8pm to 1am the next morning. Specifically, if that transponder receives 10db during the day. At 8pm, it will change continuously from 7db to 13db. As a result, packets will be lost when the signal drops to 7db. Can anyone explain why? . Where I don't have 5G yet, and I've tried several 5G noise canceling LNB models (bought from China's taobao) but no change..

 

moonbase

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Anybody got improvement with those 5G noise canceling LNB models from China?

I imported a 5G cancelling LNBF (twin probe) from the USA and it definitely improves things.
I was getting large fluctuations in signal level from some feeds on 46.0E in C-Band using a normal C-Band LNBF without 5G filtering, in an out of a lock constantly.
With the LNBF I imported from the USA the signal fluctuation completely dissapeared and I got a rock solid 13.8dB constant lock on the feeds.

However, the best improvement according to one of the top UK DX Men on the scene is that the WR229 band pass filters perform the best.
There is one specific make of 5G band pass filter that seems to outperform other similar units, this is the "ALGA Red" which I think covers the 3.82GHz to 4.2GHz part of the C-Band frequency range.

One of these "ALGA Red" units with a WR229 flange LNB strapped on to it such as a Norsat is supposedly the best combination, way better than anything from China.
However, this type of kit is not cheap, it is pro grade kit as used by broadcasters.
 

C0der

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Thanks for the detailed info. (Link to that twin probe LNBF, maybe?)
And yeah, those are expensive.
 

Sunrise999

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Have a twin feed from Titanium do notice 1+ db loss from before.
I read he is working on a upgrade not released yet.
 

moonbase

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Thanks for the detailed info. (Link to that twin probe LNBF, maybe?)
And yeah, those are expensive.


The twin probe C-Band LNBF with 5G filtering that I imported is a Titanium C238 model, designed to operate over 3.8GHz to 4.2GHz
I do not think links to suppliers other than the forum sponsor are allowed, however, a quick google brings up a few options.
 

moonbase

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Have a twin feed from Titanium do notice 1+ db loss from before.
I read he is working on a upgrade not released yet.

That is the make I imported, the model I got was the C238 unit.

I did not notice a 1dB loss, however I did not test it for every single frequency
The feeds on 46.0E I tested it with were unable to give a stable lock with the previous LNBF but the Titanium did the job and gave a constant lock.

The other LNBF that I have read good reports about is the SatKing from Australian vendors, it is supposed to be good.
 

HBO

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I tried buying one from taobao (China) and found the signal was worse (2 dB) than the old model I was using

 

moonbase

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I tried buying one from taobao (China) and found the signal was worse (2 dB) than the old model I was using


That model covers 3.7GHz to 4.2GHz.

There can be a lot of 5G interefence coming in around 3.7GHz, it could be the bottom end cut off point that is allowing some 5G through?
It also depends on the make of LNBF and how well the manufacturer implemented the inbuilt 5G filtering circuitry, some are better than others.
 

HBO

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That model covers 3.7GHz to 4.2GHz.

There can be a lot of 5G interefence coming in around 3.7GHz, it could be the bottom end cut off point that is allowing some 5G through?
It also depends on the make of LNBF and how well the manufacturer implemented the inbuilt 5G filtering circuitry, some are better than others.

I tried it and still didn't get good results. However, the above product is cheap, (about 20 USD). I plan to buy a more expensive LNB to see if it gives better results?

 

moonbase

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I tried it and still didn't get good results. However, the above product is cheap, (about 20 USD). I plan to buy a more expensive LNB to see if it gives better results?



The specs for that LNBF you linked to say it has 3.5GHz rejection, quite a lot of 5G will get through that.
Personally, I would go for something with higher GHz rejection, possibly starting at 3.8GHz and also one of the models that gets good feedback and is more expensive.

If you have any specific satellites you use for C-Band check what are the lowest frequencies from them that you really need and then purchase 5G filtering that starts as high as possible up the C-Band range that gives you a few hundred KHz margin above the cut off. For example, if you need frequencies of 3.82 GHz and above, get 5G filtering that allows 3.8GHz to 4.2GHz through,if you need frequencies of 3.92 GHz and above, get 5G filtering that allows 3.9GHz to 4.2GHz through.
 

mdkgr

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Cband signals are always changing. The area where I live often experiences satellite signals fluctuating from +- 3DB from 8pm to 1am the next morning. Specifically, if that transponder receives 10db during the day. At 8pm, it will change continuously from 7db to 13db. As a result, packets will be lost when the signal drops to 7db. Can anyone explain why? . Where I don't have 5G yet, and I've tried several 5G noise canceling LNB models (bought from China's taobao) but no change..



It is a weird situation because no 5G as you said, but there is theoriticall explanation

1) Local Carriers (5G) are testing to deploy maybe during the time you refered and then there is signal gain or loss depending on frequency they are working on

2) Usually you should get less db during a sunny day and when sun goes off signal should rise but your signal seems to come and go, this situation some times occurs when the signal is too strong and needs reallingment at the moment or some rf filter which cuts db + also SAT carriers some of their TP are steerable so you need reallingment for sure if this happens

3) If you are locking steady for a long time i dont think it is 5G interference, if there was you would not lock at any time
 
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moonbase

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Cband signals are always changing. The area where I live often experiences satellite signals fluctuating from +- 3DB from 8pm to 1am the next morning. Specifically, if that transponder receives 10db during the day. At 8pm, it will change continuously from 7db to 13db. As a result, packets will be lost when the signal drops to 7db. Can anyone explain why? . Where I don't have 5G yet, and I've tried several 5G noise canceling LNB models (bought from China's taobao) but no change..


C-Band signals can vary over the course of a day.

I have attached below a chart that shows how a few signals from 51.5E varied in dB level when monitored over a 14 hour period on the same day.
The chart is an old chart I created a couple of years ago so the frequencies may no longer be active, however, the signal level variance over a day is still observable for a lot of C-Band frequencies.

.
C-Band Signal Evolution.jpg
 

moonbase

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If you need really good 5G filters you should try Viking satcom


Viking Satcom are good professional grade products, possibly re-badged Norsat stuff or other commercial RF manufacturers products?
In a commercial environment products such as these would be used routinely as the expense is not an issue.

For hobby DX'ers, unless they are "Extreme Ultras" the cost can be prohibitive, hence the popular use of 5G filtering twin probe LNBF's in the hobby scene.
 

mdkgr

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Viking Satcom are good professional grade products, possibly re-badged Norsat stuff or other commercial RF manufacturers products?
In a commercial environment products such as these would be used routinely as the expense is not an issue.

For hobby DX'ers, unless they are "Extreme Ultras" the cost can be prohibitive, hence the popular use of 5G filtering twin probe LNBF's in the hobby scene.
Rebadging happens a lot these days, i have no idea if they rebabge or they are on some co-op which happens a lot also these days.

You are correct, basically its situation depending the need of this kind of equipment but its good to know it at least as a reference whats going on, the Titanium + other similar lnbfs have different models usually depending on region so they cut region specific band. 5G carriers use different bands in every region.

Hope this clarifies something.

Best regards
 

Sunrise999

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He said when testing there was something he didn't like and was doing more testing.
Will post if more information is posted.
 

BLACKCRUSADER

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In addition to 5g lnb you may also need 5g Band Pass Filters.
You can get them from Norsat.
I use bandpass filters and 5g LNB's.
The cheap stuff isn't of any use
 

moonbase

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In addition to 5g lnb you may also need 5g Band Pass Filters.
You can get them from Norsat.
I use bandpass filters and 5g LNB's.
The cheap stuff isn't of any use


Yes, for serious use 5G band pass filters from the likes of ALGA, Norsat and XMW are better than the cheapo LNBF options with internal filtering.
 
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