LNB Life-span?

[esto]

How often should a LNB be replaced? As they are relatively cheap electronic components (ie: 10 EUR on average) and left exposed to the environment 24/7, I imagine they must start degrading at some point, even tho they may keep working.

Has anyone made any comparison tests, replacing a LNB that's been in service for several years with a new one of the same make/model and see if there was any improvement in quality?

Or is there any "rule of thumb" that a LNB should be swapped out every "x" number of years?

Thanks.

 

[Analoguesat]

It depends on the environmental conditions they are exposed to. In Mediterranean areas, the life span of lnb's can be as little as 2 years. Here in Scotland Ive got lnb';s which are fine after nearly 10 years.

However at the end of the day they are cheap enough these days to just remove and replace if reception seems to be dropping off.

 

[Lazarus]

I can't recall seeing much evidence, if any, of degradation.

Generally, they work or they don't.

 

[Analoguesat]

You can easily tell if an lnb is failing due to heat. Wait for the signals to disappear on a hot day, then chuck a jug of cold water over the lnb case. If the signals come back the lnb is goosed.

 

[Mickha]

Mine's just gone Kaput after 20 years of good service !!!!!!!! Thankfully I have an old 80cm dish, and LNB, to cover until the new one arrives !!!!!

 

[Channel Hopper]

The stability of the LNB is the first to start failing in many cases, dont forget the components inside are at the centre of a parabolic cooker for the majority of their life, the solder inside has been known to flow on some larger systems.

As for noise figure, the LNB is (on domestic systems) the least significant part that adds up to the whole noise within the system. Changing it may of course help, but in many cases the action of unscrewing the cable from the F plug will clean up another source of signal degradation.

 

[Terryl]

MTBF should be around 10000 hours on most, (if they use standard commercial parts) we use to cycle them from + 50 degrees C to -30 degrees C over a 24 hour period at 50 power cycles per day (commercial LNB’s) over a 1 month period, had 3 out of 50 fail. (on a good day)

Most of the time it’s the LO’s that drift off frequency due to aging and loose lock.

 

[esto]

MTBF should be around 10000 hours on most, (if they use standard commercial parts) we use to cycle them from + 50 degrees C to -30 degrees C over a 24 hour period at 50 power cycles per day (commercial LNB’s) over a 1 month period, had 3 out of 50 fail. (on a good day)

Most of the time it’s the LO’s that drift off frequency due to aging and loose lock.

MTBF of 10,000 hours? According to my calculator, thats about one failure every 416 days. I think most typical LNB's should go longer than that. What make of LNB's were you using, and why were you doing these tests? It's kind of interesting, that most sat-TV LNB manufacturers don't usually state a MTBF in their product specs. Higher-end equipment always should state a MTBF, but I guess they don't bother with $10 over-the-counter LNB's.

 

[sonnetpete]

MTBF of 10,000 hours? According to my calculator, thats about one failure every 416 days.

Yes it is, though you're assuming the LNB is in use 24/7. If you were to use a figure of 14 hours of use per day (0900 - 2300) it's a lifetime of just over 714 days, or a bit less than two years. It still doesn't seem a long time for an LNB, though at €10 each, replacing it every other year isn't too hard on the pocket.

 

[PaulR]

Yes it is, though you're assuming the LNB is in use 24/7.

If you have any of $ly's boxes or a Distrubution/Amplifier (and possibly other boxes such as Freesat?) hung on the end of the cable then you will as these power the LNB all the time.

Regardless, I agree with the general feeling that it still isn't a long time. And I do understand that MTBF is a theoretical feature worked out mathematically from individual components.

Terry, are you sure there's not a zero missing and it should be 100,000 hours? That would make more sense.

 

[Channel Hopper]

There was one LNB brand (Wiscom ?) that I recall having many more failures than the opposition. Most of the ones I replaced had started giving trouble just outside a year.


. Some may have seen their quad LNBs on zone 1's.

 

[Lazarus]

Wistron is, I believe, the name of the poor quality brand, CH.

 

[Terryl]

Acccck you all are right I missed a "0" it should be 100,000 hours, or about 11 years to an estimated MBTF.

The old eyes are getting worse every day, time for a bigger monitor.

 

[fergyc]

You can easily tell if an lnb is failing due to heat. Wait for the signals to disappear on a hot day, then chuck a jug of cold water over the lnb case. If the signals come back the lnb is goosed.

Now there's an idea! Watercooled LNBs

 

[archive10]

Now there's an idea! Watercooled LNBs

Oh, we have that here in Denmark, you know.
It's called weather.

 

[Vipersan]

Oh, we have that here in Denmark, you know.
It's called weather.

..I Concur st1 ...we have a similar setup here in the NW of the UK ..
Where it tends to rain ...every other day..
Whilst London and the East and the South have been baking ...and crying out for water ..
We in Manchester have entered monsoon season again..
by my calculations ..its rained every day since my old dad went on holiday 2 weeks ago..
Perfectly normal for humans to rust here..
;)
VS

 

[archive10]

I know, I used to live in the UK. And I can tell you, the south has a much more beneign rain-pattern than north and Denmark for that matter. For example, we have this 3-day constant gray drizzle which just did not seem to occur in the south of UK where I spent a handful of years.

...but back to the subject. I wonder how much is general evaporation of electronics, and how much is due to the solar eclipse of the LNB twice a year. I would also speculate that larger dishes damage the LNB more from this phenomena, so you should actually see a higher replacement frequency on those. Not to speak of the reason why some LNBs are much pricier than others - if engineered to, say, MILSPEC standards then these things should just last and last. But as the old truth goes, you almost always get what you pay for. A standard LNB at EUR 6.90 is probably not going to outlast a EUR 35 semi-pro LNB...

 

[Channel Hopper]

But as the old truth goes, you almost always get what you pay for. A standard LNB at EUR 6.90 is probably not going to outlast a EUR 35 semi-pro LNB...

Problem is, a number of branded LNBs on the market are the EUR 6.90 ones, marked up to EUR 35. Gold plated stickers are rather expensive it seems.

 

[Lazarus]

Especially if the gold plating is "oxygen free" ................