I'm getting active again on HF and VHF, and I've discovered that my Nanostation Loco M2 produces quite a few birdies throughout those bands. The main type of RFI is a form of random beeping that sounds much like a CW QSO when you tune by.
While I can probably move the unit out of direct view of my other antennas, does anybody else have any suggestions on how to have everything better coexist? I'm using the recommended shielded Cat 5 cable, though I'm not doing anything special to ground the shield at the PoE injector other than to connect the injector to a 3-pin outlet.
Thanks.
We've been successful at a repeater site in reducing interference to a VHF repeater (6 meters, specifically) with a combination of chokes on Ethernet cable and power cables. In this specific case we also had to use some vertical separation between the node and the repeater antenna, and while it may not have been strictly needed we put a shield on the Rocket sector antenna. The combination of all of those worked.
You may swap out the PoE adapter as well. They can produce noise.
I believe another thread has this discussion as well. (Try the forum search)
This is a list of ethernet birdies I've heard on my HF rig. The house has ethernet cables all over the place, and these existed before I got any Ubiquiti devices.
Conrad, I searched the forum for "RFI" and was actually a little surprised I didn't find anything relevant. Can I have a link to the thread?
Bob, thanks for the list, it's pretty extensive! I haven't confirmed all of my birdies as coming from the Ubiquiti, nor would I expect them to as I also have Ethernet cable running all over the place. Come to think of it, many are currently unused as I wasn't counting on WiFi when I pulled them through the attic in 1995 or so. But I did confirm that some of the important ones (including the "false CW") was coming from the Ubiquity unit.
Come to think of it, when we took some of these units up Mt Soledad for testing I had a lot of problems with the FM and TV broadcast stations ingressing into the Ethernet cables. Sometimes I couldn't even maintain a link between my laptop and the unit. And RF does flow both ways through a leak.
Ferrite chokes sound like a very good idea, thanks. I may use several types together to get good coverage at both HF and UHF. Got a recommended source?
Thanks.
Here's what we've used with good results: UF70B
This sounds vaguely (maybe exactly) like the QRM that the ISP part of AT&T created when they installed unshielded Ethernet cables. They have since sold that off so it's someone else's problem and we changed to a different ISP.
The fix was getting shielded Ethernet cable installed properly. It has been several weeks that I read thru the Ubiquiti Ethernet cable installation recommendations, but I am pretty sure that there is something about connecting the outer shield to ground at only one end. There is a recommendation about which end and why ... sorry, I don't remember that detail and I can't presently take the time to dig thru the site to find.
These things are computers, after all, and some of them are in plastic cases.
So mounting those right next to your weak-signal antennas is just a plain bad idea.
See what they radiate through the plastic case, in my posting here:
http://www.aredn.org/content/rocket-shields
The nanostation is going to be a bit harder to shield than the Rocket, but there is some after-market shielding available.
As others mentioned, make sure you eliminate the POE and cat 5 cable as sources/antennas too.