Fluctuating signal quality

[manatails]

Hello,
I recently got myself a 1.8m jonsa 6-piece dish for receiving some C-band satellites
at first I could not lock on to any of the satellites, including those with 40+db footprints in my area

I heard a lot of bad reviews for jonsa dishes but I thought it wouldn't be this bad so I figured that it might be because of the cell tower located right next to my place, so I replaced the LNB with the one with an internal 5G filter. It seems to give slightly better results as I can now lock on to a couple of satellites but still signal quality fluctuates a lot and loses the lock every second or so.
Signal strength is about 70% but signal quality fluctuates from 0% to 90% even though nothing is moving.
Does it mean that I am still getting interference? Would I be able to get better results if I buy a dedicated bandpass filter?
And why are dedicated bandpass filters so expensive? An LNB with internal 5G filter costs less than $20 but dedicated bandpass filters that you connect to the feedhorn costs like $100, I wonder why.

 

[Mickha]

It might be your connections. I once had fluctuating signal quality, due to my F Connectors being too tight, for the cable, and in screwing them om, I ended up cutting the copper braid, causing intermittent problems.

 

[manatails]

It might be your connections. I once had fluctuating signal quality, due to my F Connectors being too tight, for the cable, and in screwing them om, I ended up cutting the copper braid, causing intermittent problems.
View attachment 157157

Thanks for the suggestion but I've already tried different cables so I can rule out cable issues. I also have a separate Ku band offset dish that work just fine.

 

[anto@]

I only know about lnbs with integrated 5 G filters costing 20 dollars, the Chinese ones, which are of poor quality, if you want a good filter you have to get the 5 G reed titanium filters, which cost 100 dollars with shipping
from this point you can then see if you find any signals, if even with this lnb you don't find anything it means that your Jonsa is poor too

 

[el bandido]

Hello,
I recently got myself a 1.8m jonsa 6-piece dish for receiving some C-band satellites
at first I could not lock on to any of the satellites, including those with 40+db footprints in my area

I heard a lot of bad reviews for jonsa dishes but I thought it wouldn't be this bad so I figured that it might be because of the cell tower located right next to my place, so I replaced the LNB with the one with an internal 5G filter. It seems to give slightly better results as I can now lock on to a couple of satellites but still signal quality fluctuates a lot and loses the lock every second or so.
Signal strength is about 70% but signal quality fluctuates from 0% to 90% even though nothing is moving.
Does it mean that I am still getting interference? Would I be able to get better results if I buy a dedicated bandpass filter?
And why are dedicated bandpass filters so expensive? An LNB with internal 5G filter costs less than $20 but dedicated bandpass filters that you connect to the feedhorn costs like $100, I wonder why.

Hi
I recently spent close to $600.00 U.S. for two 5G lnb filters. The price of filtering 5G will certainly fall, but right now filters are high.

Some lnbf's will have or claim to have 5G filters. I don't know how well they work because I have a pair of Norsat lnb's.

The trick to this 5G stuff is to understand what is happening. To do that, you need a signal analyzer to see what is happening and to see the actual 5G interference. You are blind without an analyzer and will be left guessing what the problem is or if the parts you install are even working. Your problem may actually be 5G or it could be something else. No way to tell for certain without an analyzer.

The signal analyzer will need to cover at least 950 MHz to 2150 MHz. You will also need cables and and a splitter that has voltage only on One side so you can "see" what the lnb or lnbf is doing. Voltage cannot be allowed into the analyzer or you will burn it up.

Signal analyzers are available here for around 50 U.S. dollars. I have two signal analyzers, one similar to what is shown below, and also a Tiny SA Ultra. Really you don't need anything expensive. You just need a basic signal analyzer so you can see what is happening in the lnb or lnbf. You are working blind without a signal analyzer.

 

[manatails]

I bought a coaxial tap and was able to feed the input to the SDR. I can see the interfering signal but not sure if it is from 5G. Meanwhile I ordered a bandpass filter anyway...

 

[Channel Hopper]

If you can post a wider scan of the IF range it would help identify if the noise floor mimics that of a 5G tower, along with the tower's postcode and which direction it is from you.

 

[John]

View attachment 157259

I bought a coaxial tap and was able to feed the input to the SDR. I can see the interfering signal but not sure if it is from 5G. Meanwhile I ordered a bandpass filter anyway...

What is the LO frequency of the Cband lnb / lnbf you are using that your SDR plot has used ? ... if it's 5150 then the signal you have indicated is 4.052 GHz - well away from the main 5G fundamental frequencies and also does not look like a 5G signal plot. Iv'e not checked on the 5G services in your part of the world have reached up to 3.799 GHz and lower to 3.4GHz area ?? then you should see interference spikes etc on your IF SDR plot from around 1351 MHz to 1750 MHz area.
Iv'e been evaluating the new Titanium 5G Red lnbf 3800~4.2GHz for the last month and so far have been very impressed with it dealing with heavy 5G interference.

 

[manatails]

My SDR only supports up to 56mhz bandwidth and GQRX doesn't support sweep scanning...

But I do see 5G/LTE like signals from 1450MHz and up (3700Mhz and down with 5150MHz LN and 5G frequency allocation in this region is from 3.4GHz to 3.7GHz... I guess I can take that as evidence?