Is my faulty lnb my fault

F

Fredyflame

New Member
My Satellite Setup
Netgear 90cm dish , Manhatten receiver
My Location
France
I have a titanium twin lnb which stopped working
I sent it back only to be told that it was corroded due to poor installation as I had not pulled down the extension section which I didn't even know existed.
They are saying this has caused the corrosion but on looking at the 2 photos they sent me it looks more protected with the 2 connections not extended
Are they correct or just trying it on
Thanks
Dropbox - File 01-11-2016, 17 40 51.jpeg
 
I think you could be misinterpreting the photos because the connections ("F-connectors") themselves are fixed to the internal main body of the LNB and don't "extend" ! What extends is a plastic cover which can be slid down to cover the connectors after the cables has been attached - as shown in the image on the left.

That is supposed to stop water and moisture getting to the mated-pairs of LNB connector and cable connector, but probably only helps to prevent actual rainwater getting into them - and does little or nothing to stop the moisture in the air (which is "everywhere") getting in and causing internal corrosion.

In reality, if you want to prevent this sort of thing happening, you need to take further precautions other than just the slide-down cover, and if you didn't/don't then internal corrosion of the LNB connectors and likely right into the internal electronics of the LNB will almost certainly occur over a couple of /few years (if not sooner).

The generally recommended methods (and people vary on those!) are:
- in your case, replace the F-connectors on the cables as the existing ones will almost certainly already be corroded
- put some silicone (not "silicon", and definitely not silicon sealant which contains corrosive acetic acid!) grease into the male F-connector on the end of the cable before you screw it onto the female F-connector on the LNB;
- make sure the male F-connector is tightly fitted onto the female F-connector, and then tightly wrap the whole joint, right down onto the exposed cable sheath, with self-amalgamating tape (NOT normal "insulating tape"), having "pulled it hard" to stretch it and so activate the chemical reaction that causes the tape to "set" into a solid (and water/moisture resistant, if you do it right) mass.
- a combo of the above two, but if you do that, then be very careful not to get any grease on the outside of the mated pairs or else the self-amalgamating tape won't adhere to the metal connectors.

Another thing to avoid if possible is using sat cables that contain any aluminium - such as those with "copper coated aluminium" (CCA) cores or mesh screens made of aluminium - because aluminium corrodes very easily, and always have a "drip loop" in the cable before it connects to the LNB so that rainwater/moisture run the bottom of that and not onto the F-connector.
 
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Thank you
The only weather protection I had was the rubber sleeves on the connectors.
Unfortunately my replacement that I bought has already lost one channel (if that's the correct term)
So I will follow your advice
Thanks again for the comprehensive reply
 
Agree with @jeallen01 to a far extent: You need to pull down the pull-down cover to achieve cover.
(If not installed according to instruction...)

That being said, most LNBs fry out in a couple of years.
I don't know how long you LNB has been up, but I replace LNBs every 3-4 years, irrespective of cover being pulled down or not.

Nevertheless, the price of a new LNB makes you wanna go "what the heck", and just buy a new one...
 
I'm still using LNB's that have been in-place for over ten years, never touched after install.

Just buy good high quality LNB's and your set.

And a proper install will help out a bit.
 
TBH, I never change LNBs because they are faulty, and as @Terryl , have some LNBs older than 10 years. In fact, out of ~50 LNBs (maybe even more) in stock I doubt there are some faulty.
 
Only ever had one failure; A Black Ultra

Mostly, they are bombproof.
 
RimaNTSS said:
TBH, I never change LNBs because they are faulty, and as @Terryl , have some LNBs older than 10 years. In fact, out of ~50 LNBs (maybe even more) in stock I doubt there are some faulty.
Click to expand...
Could be I'm in a very humid coastal environment, or it may be due to the temperature hovering around freezing in the winter.
But I've had several LNBs either stopped working entirely, or on one or two outputs.
I do try to seal cable attachments and the like, but I do seem to loose one or two every now and then...

Maybe it's just bad Karma?
 
Fredy

If you do use the rubber sleeves then fill those with the silicone grease before you slide them over the mated F-connector pairs and that "should" do the trick without the need for the self-amalgamating tape. For my part, I have rarely had LNB failures except when the connector sealing has failed (and also except when I used - never again - silicone sealant on one over 20 yrs ago ! :( )

PS: very gently "nip" the male F-connector nut up before you do the above to make sure the connector-pair is firmly mated.
 
Ok
Thanks
Just a point but if the failure was due to the sleeve not being pulled down surely there should be signs of corrosion on the threads?
Both the threads and connectors were perfectly clean
I have lost one output on the replacement already in less than 10 months
Tony
 
Clean connectors indicates that good quality F-connectors were used on the LNB and the cables - but there is a small hole in the female connector on the LNB body into which the coax core in the male plug fits - maybe the sealing behind that was not good, or maybe there was even an incorrectly sealed joint in the internal metal enclosure around the electronics (both would indicate manufacturing faults)?

Another thought from a different angle (literally!) - how tightly does the plastic feedhorn cover fit over the end of the feedhorn? If it were loose or cracked (but the photos don't seem to indicate that it was) then it would be possible for moisture to get right inside the LNB inner enclosure from that direction.

Is the replacement LNB the same type as the one that originally failed (because that would tend to indicate a general product weakness)?

If that is the case then I would be tempted to try one from another manufacturer (personally I'm OK with Technomate, although I do now remember one of their Gold Twins failing after about 4-5yrs, and Inverto, but I know others here have different preferences)

Finally, you can get the silicone grease on ebay.
 
Personally, I never bother with waterproof tape, grease or rubber sleeves on LNB´s with drop down weather shields. I only use the rubber sleeves on open connections, for example on the Invacom prime focus LNB. I do however use F type connectors with the rubber o-ring in them to prevent any water ingress down the threads. However, using the drop down shield will prevent rain and probably 90% of water caused by dew etc.
Regards faulty LNB´s, I have changed quite a lot. A few months / years in the Spanish sun combined with winter night temperatures falling below freezing on occasions does take its toll some times. Also, as many of the budget / cheaper LNB´s are mass produced with little quality control, or could even be copies, you have to expect failures now and then.
With regard to you particular issue, could be a bad batch from the manufacturer. With regards to the corrosion ( which I cannot see from the picture ) what can anyone say? If they say it´s your fault for not using the weather shield I doubt they will change their mind even if everyone here had the same view that it is not the fault. Try an alternative brand from another manufacturer.
I hate to put it like this, but I fear you are :-deadhorse
 
Fredyflame said:
I have a titanium twin lnb which stopped working
I sent it back only to be told that it was corroded due to poor installation as I had not pulled down the extension section which I didn't even know existed.
They are saying this has caused the corrosion but on looking at the 2 photos they sent me it looks more protected with the 2 connections not extended
Click to expand...

What part was corroded, did they say? The F-female connectors look pretty good.
The pull-down rain protection is mainly for the F-connectors, I believe.
If something inside would be corroded, that would be because poor quality of the LNB construction, or because of some sort of leakage from somewhere at the top of the LNB, I would say.

So I am confused, as you are......

greetz,
A33
 
@Milamber

Good point about wide ambient temperature changes - most "cheap" electronic circuits don't like that because it causes PCBs, electronic components and connectors to expand in the heat and contract in the cold, and that can cause poorly-made solder joints to crack - even if there is no moisture in there.

@a33

More or less what I was saying about moisture getting in via the LNB horn end-cover, or via some sort of cracking/separation in the joints between the various parts of the outer plastic enclosure (wide temperatures don't help that either, particularly the plastics!), so that it gets in and around the inner metal LNB enclosure, and then via any "gaps" in that to the actual electronics.
 
Thanks guys
I have sent them some of your feedback, but as has been pointed out quite amusingly I don't hold out much hope.
It is in France and gets extremes of temp so I will buy a more expensive one, although this model got good write ups
Tony
 
Might be worth asking around your neighbourhood about any good/bad experiences of which LNBs are reliable, or not, in your location and environment!
 
Tony Cu****, if you have the ability to send me a personal message, do so. If you do not, ask a passing " Forum God " or answer here and I will send you a message.
I will send you a LNB that will give better results on reception and can take the heat!
Now understand the Fredyflame, hard name to live up to!
 
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