Don't laugh, but is this a good basic test for an LNBF??

[Doorguru]

I have some questionable LNBF's that have been sitting around for years. I tried to test them on my dish but none seemed to work. This could have been caused by improper focal or alignment problems. How could all three be bad?? I was sitting around tonight and came up with this idea. Is this ridiculous or does it show that the LNBF is basically working?

 

[KE4EST]

It does appear to be picking up the frequency.
I assume you don't have a dish that is working?

What kind of dish were you using? Receiver? What satellite were you aiming for? What LO did you have set? What frequency did you have input to test on your receiver?

 

[KE4EST]

Okay I found your info in another thread. It would be best to keep everything in one thread.
...but since this one is asking how to test an LNBF, I'll leave it and respond in the other one.

 

[spongella]

I thought microwave oven frequencies are around 2.5 Gigs? Have to check that video out, thanks doorguru.

 

[Doorguru]

Something to consider though, it may cause damage to the LNB (?)

 

[FTA4PA]

I have some questionable LNBF's that have been sitting around for years. I tried to test them on my dish but none seemed to work. This could have been caused by improper focal or alignment problems. How could all three be bad?? I was sitting around tonight and came up with this idea. Is this ridiculous or does it show that the LNBF is basically working?

Interesting! I will have to try that with a known good and bad lnbf.

 

[Titanium]

Well.... it would indicate some signal above the noise floor was being amplified, but this "test" wouldn't indicate if the LO drifted, polarity / band switching failure or failing amplifier.

 

[Inclined Orbit]

Many microwave ovens are in the 915MHz range. Either way, the Ku band LNB front end near 12GHz is probably filtered and should not respond to 900MHz or 2.5GHz and you may be getting into the IF amplifier at L-band 950 to 1450MHz range. The RF leakage from a microwave oven can be well below OSHA standards but huge to microwave receiving equipment.

 

[primestar31]

I really hope you didn't run that microwave without something inside it, such as a coffee cup full of water. If not, you can damage the magnetron tube... It can literally cook itself to death from the reflected waves of energy.

 

[spongella]

Would be interesting to try this using a Bluetooth xmitter instead of a microwave as Bluetooth's about same frequency as microwave ovens.

 

[Cham]

Likely just picking up the microwave noise in the IF (feedline, connections, etc) range rather than 12 GHz from a microwave. Not much around that's easily accessible that generates RF in the Ku spectrum that your LNBF/receiver would recognize other than the satellite downlinks, unless you can find a signal generator that produces DVB-S/S2 at Ku frequencies.

If it can't pick up anything using a known dish refelctor aimed at a good strong signal source such as G19 at 97W (Ku) with the required LO programmed into your receiver, then the LNBF isn't likely functioning or is of no use for general FTA reception. Ku LNBFs for FTA are reletively inexpensive, best to buy a new one to try, never hurts to have a spare if the problem turns out to be elsewhere (receiver, feedline, etc.).