6GHz amplifier for C5C


#1

Hi support team, I have a question: do you recommend installing an RF amplifier to increase the power of C5C between the rocket and the antenna?
If yes, what would be the recommended vendors?
My problem is : this link keeps connecting and disconnecting due to limited power (only 27 db)
Thanks


#2

Well, 27 dB is pretty powerful, unless you have an antenna that is less then 9 dB you are going to be over the EIRP for most frequencies in most places, which would be illegal and I would not recommend it.

If you are in UNII 3 in the United States it probably would be better to get a bigger antenna.

But I really don’t know enough about the link to make good recommendations.

What is the distance for the link? What is your RSSI? What antennas are you using? Is there anything blocking the links LOS? Are you sure that the antennas are properly aligned?


#3

Distance: 10Km , Band used 6…3Ghz, antenna type :UBNT 30dB , LOS clear, antenna aligned. The problem is : had lots of association/disassociation due to power. I can replace the antenna with 6Ghzones. But I thought that adding an LNA (Low Noise Amplifier) could solve the problem


#4

I apologize if I am misunderstanding, but are you using a 30 dB 3 GHz antenna? If so, yes that would cause lots of problems. Antennas are quite delicate things and using one outside of the band it was designed for will not work very well.

What kinds of RSSI are you getting?

Adding an amplifier would not be a great way to make the link better, in my opinion. You would just be throwing more power into a very inefficient system. I would try an antenna that is designed for the frequencies you are using first.

At 10 Km alignment can get a bit hard, I would recommend lowering the transmit power on each side significantly and doing the alignment off of the lower power. This will make it harder to align on a side lobe.


#5

If you actually have line of sight and aligned 30 dB antennas, +57 EIRP is far more than enough. It is more than most countries allow, though I have run into people in, uh, “disorganized” parts of the world where there were no officially-enforced rules…
But something else is wrong if you can’t hold the connection. What is the RSSI at each end? What is the noise level? What specific frequency are you on?
It is possible that the antenna you are using is out of tune, though. If you are in the 6 GHz band, which in the US and many other countries is for licensed point to point use. The UBNT antenna, designed for the 5 GHz worldwide band, may not be working well up there. Its VSWR may be out of acceptable range.
Since there are essentially no places where an “RF amplifier” of this type is legal, you can’t find one. And because it’s a TDD radio, an amp would probably block the receiver.


#6

@Fred is right, an amp would defiantly kill the RX side of the radio… So probably not a hot idea.