Re: [ldm-users] The failures and successes from 5G interference with NOAAport

• To: Gilbert Sebenste <gilbert@xxxxxxxxxxxxxxxx>
• Subject: Re: [ldm-users] The failures and successes from 5G interference with NOAAport
• From: Stephen Adams <sadams@xxxxxxxx>
• Date: Tue, 2 May 2023 22:12:51 -0500

Nice write up Gilbert. I feel your pain!
We had problems with G28 at the end that we never really solved, but a new
LNB and the switch to G31 saved us. Troubleshooting is SOOOO much fun!

*Steve Adams | AWIS Weather Services*
888.798.9955 | sadams@xxxxxxxx | www.awis.com


On Tue, May 2, 2023 at 7:58 PM Gilbert Sebenste <gilbert@xxxxxxxxxxxxxxxx>
wrote:

> Good evening everyone,
>
> I love tech. And I think it's really cool and love the speed of 5G
> technology. Of the three types of 5G, the "mid band" 5G gets you 300 mb/sec
> to 1 gb/sec speeds. How great is that?
>
> Unless, of course, it interferes with your satellite signal. And here at
> AllisonHouse, we know about that all too well.
>
> When a telecom turned on their 5G on towers close to our NOAAport receiver
> dish one fine Saturday morning, I saw that we were not getting any data
> (and was blasted out of bed from our alerting system to kindly let me know
> that, LOL!). Sure enough, we had a signal, but the carrier-to-noise (CN)
> was really low, well below what was needed to decode packets. I pretty much
> knew what that was about. Thankfully, our system instantly switched to a
> backup feed automatically, so we didn't lose any data. I talked to our
> engineer, and he immediately knew it was 5G interference from a 5G provider
> causing the issue. We ordered the 5G filter that the National Weather
> Service uses (with a very minor model difference that didn't change any of
> the specs) to solve the problem; that filter knocks that interference down
> by 30 dB, which is a lot! We got the filter installed, and we were back to
> having data, although we were losing more packets than we had before the 5G
> was turned on.
>
> Then came the NOAAport satellite move from Galaxy 28 to 31. We repointed
> the dish, and got a signal. It was a video signal that we had locked onto
> on an adjacent satellite at 121 degrees west. Oops. Then we tried to adjust
> the polarity, but after weeks of equipment failures, repoints and
> adjustments, we just couldn't lock a signal. We were told to go to a second
> engineer who could solve almost any issue. He tried and tried, and we still
> couldn't get a signal to lock. Finally, it did lock, but only
> intermittently, and still, no data. And when we saw the scope, we knew what
> it was. 5G interference! But how?
>
> Well, the frustrated engineer had the lights and bells come on in his
> head. The 5G filter we were using was foreign to him, but then he realized
> it had the specs of another brand that he saw was causing TV and radio
> stations he services to have the same issues. So, he told us we needed to
> swap our 5G filter with a much better one: the Alga Microwave C-band 5G
> filter (blue). Instead of having a 30 dB rejection spec, this one has 70
> dB+ rejection from 3900 MHZ and below, and at least 25 dB from 4200 MHZ and
> above. It was the frequencies below 3900 that were killing us, so the extra
> 40+ dB of rejection was needed.
>
> So, this past weekend, the new filter was put on. Bam! What we had locked
> on to was indeed NOAAport, and without peaking the signal, data immediately
> started coming in. The engineer peaked the dish, and then precisely
> adjusted the polarity on the LNB. This latter step is absolutely critical,
> because a video broadcast could be coming on the opposite polarity on the
> same frequency of NOAAport! In fact, a test video broadcast on the opposite
> polarity and same frequency was performed last Friday night, and no issues
> were noted on some of the other dishes I monitor. In any case, with a 3.7
> meter dish, we get a signal of roughly -26 dBm at the dish, and -33 dBm at
> our receiver, with a C/N of 16 on average on a clear day, just a touch
> lower when it's cloudy. This is lower than I want, since the NWS C/N
> standard is 17 dB, but we still have roughly 5-6 dB of signal "pad " for
> clouds and precipitation before we lose data. We should stay up unless
> rainfall rates in the path of the signal reach about 2" per hour.
>
> So, now we are back to our winning ways. We do lose a few packets here and
> there due to HVAC turning on and off every day at our location, but the
> losses are around 200 packets/day total from the 5G and RF nightmare our
> dish is located in...surrounded by towers pounding out the 300 mb/sec
> goodness, as well as 100,000 watt FM radio and 1 megawatt TV stations. And
> let me make one thing perfectly clear: I'm not mad at the telecoms at all
> about our troubles, speaking strictly for myself. Rather, I'm really not
> happy that the FCC allowed the cellular companies to intrude on the C-band
> signals in the first place. But, that ship has long sailed, so we just have
> to deal with it.
>
> I wrote this in the hopes that this could be helpful for someone. I know
> there are NOAAport 5G nightmares still going on with this, and more to come
> as telecoms build out their networks over the next 5 years.
>
> Gilbert
> --
> ----
> Opinions are not of my employer, but all facts are.
> Gilbert Sebenste
> Consulting Meteorologist
> AllisonHouse, LLC
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• References:
  • [ldm-users] The failures and successes from 5G interference with NOAAport
    • From: Gilbert Sebenste