Testing an LNB

sonnetpete

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Are satellite meters like Satlink for example capable of checking for LNB fault as in with a multimeter?

AFIK there aren't any specific testing parameters in the Satlink firmware. My meter just displays signal strength (or not if the LNB isn't connected or working). As the above postings have said, the simplest method is to substitute with a known working LNB.
 

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Seems that current draw can help evaluating the condition of an LNB (How do I test the LNB to find out if it's defective?). IMO that only shows that (some of the ?) electronics are possibly ok. Next must be to apply microwave (as from known well adjusted dish) and test frequencies \ factual output, and 14\18 v + 22khz needs testing, the receiver will do that.
 
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sonnetpete

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They don't use crystals member91040. They aren't precise enough at GHz frequencies.

They use a FET in conjunction with a dielectric resonator.

Don't ask me how you test it though (although the FET could be).

Llew
Lew , never heard of PLL Lnb's ?
The octagon Twin is PLL version with 2 Xtals , even the new Inverto KAKUO has a Xtal and no DRO adjustment skrews .
If you connect a powered satfinder to a lnb and point it in the direction of a working microwave oven , it will give signal .
Does not say all about the function of that lnb .
 

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Which model of Satlink ?
 

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Seems that current draw can help evaluating the condition of an LNB (How do I test the LNB to find out if it's defective?). IMO that only shows that (some of the ?) electronics are possibly ok. Next must be to apply microwave (as from known well adjusted dish) and test frequencies \ factual output, and 14\18 v + 22khz needs testing, the receiver will do that.

You can not test this without a very special RF interface circuit designed to measure DC current on an active RF circuit, using a standard DC current meter will shut down the LNB's functionality and you will not get the correct readings
 
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My Smart S1 has auto short detection, it will tell you if there is cable or LNB short ( think it´s more to protect the tester than anything else ) otherwise it sees a signal or it don´t.
Good test for a suspected faulty LNB is to drop it from a ten story building, it it bounces more than three times it´s working ok!:-lol
 

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Refering to the article mentionned in my post above, did a quick test by applying 14V in series with a multimeter set for 200mA, results on some known working lnb's (90 to 140 mA) seems to match info in the article.

This at least confirm that there is 'something' in the LNB that's waking up :O) and working ok (zero or very high current drain would IMO clearly indicate a defective lnb). But that's it, this can't test anything regarding it's ability when put in front of a sat signal.
 

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Terryl

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I use the .44 magnum test, if I miss the LNB is good, if I hit it the LNB is faulty.

Somewhere in my lab notes I have the modifications that can be done to an OEM Duck Network** receiver, once done you can use a simple DVM to measure the DC voltage and DC current draw on the LNB when on an active satellite(s) and transponder(s), I can look for them but would require a Sherpa guide, some long rope and a S&R dog to find me (us) if we get lost.

I did it many many years ago, so I don't have any idea where to start looking.

**don't know if I can mention the real name of that provider....:-deadhorse
 

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Surveys best LNB C Band

Whatever, still think their LNB is the best so far! :D:D
 
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