Posts by SWL-LuisBorges

Quote from HB9SKA

If this discussion does not apply QO-100, then it should be moved in a general forum.

If the "satellite" has a RHCP polarization, then the helix must be also RHCP. A helix-feeder mounted at a dish must be LHCP because the wave is reflected and the polarization inverted. A TV LNB has only vertical or horizontal polarization.

Hope this helps.

Yeah, sorry. I ended up posting here because I was talking about LNB

Yes Yes. RHCP. My question is, the LNB seller said to me, "Good afternoon Luis, you will need to do the conversion first. Typically in the feed assembly or separate polarizer. The LNB reads horizontal."

I usually do this conversion when I work with waveguides. This time is something new for me. I'm just using an SMA cable connecting my antenna and the LNB, as shown in the diagram.

Thanks

I plan to do some more testing. I believe the switch mode power supplies is causing a lot of noise.

Quote from on7kec

I need to use a bias-tee?...YES .If you dont want to rip your equipment... yes....

A t-connecter directly to the powersuplly and your spectrum analyzer!!!!

I thought about using the bias tee, but my colleague said the spectrum analyzer had a DC blocker so it would have no problem.

Quote from DD1US

Hi,
please explain a bit more detailed what you want to accomplish.
The second diagram you posted where you want to connect a DC power supply and an oscilloscope via a PL-Tee to an amplifier does not make any sense ...

Kind regards

Matthias

I need to use a bias-tee?

Actually I'm testing with another satellite. Is that I always got good tips in general in this forum hehe So I thought about trying to clear this question here.

But it is a satellite where the downlink is RHCP.