You are here

Rocket Shields

5 posts / 0 new
Last post
K5DLQ's picture
Rocket Shields
KE2N's picture

I should mention that I do not use the Ubiquiti POE out at the tower either.  I do use shielding on the M5. Because of its plastic case, it exhibits some radiation from the circuit boards that other postings in other forums have noted.  As a test, I placed one M5 next to an antenna probe connected to my old spectrum analyzer on my workbench. The M5 antenna ports are terminated in shielded SMA dummy-loads.

See the attached. In he middle of the trace, I turned OFF the M5 for about 1 minute.
What you see during OFF condition is the RF environment in my workshop. Big yellow stripe at 100 MHz is the FM broadcast band. Stripes around 500 MHz are UHF TV stations. Others are computers etc. So I need a Faraday cage.
But you can clearly see the RF "hash" that the M5 radiates when it is on. including two fairly strong carriers at about 380 MHz and 1170 MHz. These frequencies might change with different MCS operations.  

Note: Here the M5 was idling and not associated. The spectrum analyzer goes to 1.8 GHz here but the receive pre-amp is only good to 1.3 GHz. So it looks quiet above that frequency, even though it might not be.



Image Attachments: 
POE question

I should mention that I do not use the Ubiquiti POE out at the tower either.

KE2N, how do you power Ubiquiti then, or do you just mean that you do not use the Ubiquiti-branded POE injectors at the tower?

What are your thoughts on the TP-ESP-100-POE24?

Jason de KG6H

KE2N's picture

I only have a couple of radios, so I use the 24 volt, 5 port "TOUGHSwitch PoE".  
Because I have a tower camera that uses 48 VDC, I run 48 VDC out to the tower. I use a DC/DC converter to feed the toughswitch at 24 volts. (I tried the 48 volt version of the TS, but it overheated and dropped the connections - in bench testing - so I returned it).

The data connection back to the house uses a GigaBit fiber optic (Chinese, eBay, works great) also powered off the 48 VDC 

I like the TS because I can check status (and if needed cycle power to individual units) without getting off my chair here in the shack. My tower stuff is all OEM firmware and the TS is included in the software tools that Ubiquiti supplies (airVIEW - also show up in discovery).

The surge arrester you show would need to be inside a rain-proof container.  The Ubiquiti one (ETH-SP) is somewhat rain resistant, as-is.


WL7COO's picture
Has anyone looked at these and gathered empirical data?

RF Anti-noise Shield for Ubiquiti Nanostation   found on ebay at ubntshop.  

Is it worth it ?  
I am hearing noise that I didn't used to on handhelds in the same room where an NSM2 is connecting to a Mtn Top 7.4 miles away and about 2400' higher and I can't decide of it is the wall wart for the POE injector or the radio.  A 15' Cat5e cable connects it to any of several computers on my desk and none of them seem to mind but specific 2 meter dual vfo combinations that used to work well suddenly got noisy. 

Especially for Repeater sites if basic metal shielding on the back & sides of NSMs are useful, these too seem like a good idea.
If I'm hearing noise from the wall wart or injector I'll try to replace AC with Battery & passive poe in the time left before a Rocket goes up on the tower and the NSM2 into a go-kit.

I am amazed that the link margin is between 17 & 19 db with the NSM2 in a suction cup mount on the inside of the glass of a living room window.  
The view is approximately 80% obscured through a pine tree not 40' from the window at abut 2 or 3 degrees away from the trunk.

TIA, 73


Image Attachments: 

Theme by Danetsoft and Danang Probo Sayekti inspired by Maksimer