[Skimmertalk] Yes...A RP-16 can be made to work over a Wi-Fi link!

[Ted Gisske]

Hmmm…

The price must have gone up after my recommendation :>} I paid $35 less just a week or so ago.

 

It’s been quite nice WX in WI since I put the link up. No rain, or snow, for that matter. I imagine that there will be some WX related attenuation, as it runs at 5GHz. The radio/antennas come with a pretty nice HTML web-based app to see what the system is doing. There is even a 2.4 GHz Wi-Fi system with a range of about a foot built into each antenna to connect to a cell-phone app for local management and dish-aiming.

 

RE: Motivation.

Got no sunspots…Might as well play with microwaves.

 

73,

Ted

K9IMM

 

 

From: Skimmertalk [mailto:skimmertalk-bounces at contesting.com] On Behalf Of Bob Wilson, N6TV
Sent: Sunday, August 04, 2019 11:48 PM
To: SkimmerTalk Reflector
Subject: Re: [Skimmertalk] Yes...A RP-16 can be made to work over a Wi-Fi link!

 

Congrats.  Good to know.  Curious to know if it stays connected during heavy snow or rain.

 

But it's about half the cost of the RP-16, so one has to be rather motivated to do this.

 

https://www.amazon.com/Ubiquiti-PowerBeam-PBE-5AC-Gen2-Performance-airMAX/dp/B076BMQ2CH/

 

73,
Bob, N6TV

 

On Sun, Aug 4, 2019, 6:57 PM Ted Gisske <gisske at offex.com> wrote:

Yep…I got it to work.

 

It wasn’t trivial, but it is working. My skimmer is located about 150’ from my shack, with the antenna (a Cushcraft R7) up on a 50’ tower. It is “remotely” located, as I am a QRO contester, and want it to still work during contests. It is very inconvenient to run some sort of wired Ethernet link to my skimmer, so I explored ways to do it via radio (we are hams, after all..).

 

My skimmer is in an unheated pole-shed in WI, so sees some pretty extreme temps. I have been running the skimmer in the pole-shed for 4+ years, but the environment is pretty harsh and have I had computer (and frequency stability) issues over time. A GPS disciplined LO for my QS1R fixed the stability problems, and a 802.11g Wi-Fi link got data to the shack. A lot better idea seemed to be running just the skimmer SDR in the shed and running the computing part of the setup in a nice cozy shack.

 

That wasn’t easy with my QS1R, as it ran off a USB cable. I recently upgraded to a Red Pitaya 16-bit SDR, which runs off an Ethernet link, so, if I could get a reasonably fast Ethernet link to my remote receiver, I would be in high clover.

 

That, however, was a significant challenge. The RP-16 is a promiscuous consumer of bandwidth. A fully commissioned RP-16 (sixteen 192 kHz slices) munches up 160Mbps. You ain’t gonna get that bandwidth out of an 802.11 a/b/g/n Wi-Fi link. Further complicating the issue is that a dead-solid Wi-Fi link is necessary, as Skimmer Server locks up on a data dropout and you have to go thru a fairly tedious reboot sequence to get it QRV. Both Skimmer Server and WSJT-X also get very deaf if they don’t get the full 10 Mbps/slice connectivity.

 

It is possible to make it all work, though. A relatively new (~5 years old) Wi-Fi standard called 802.11ac, featuring “Gigabit” speed is available at a reasonable price. I bought a couple of Ubiquiti NanoBeam 5AC Gen2 antenna/radio modules for a reasonable price from Amazon. They form a transparent RF Ethernet bridge from the shack to the shed. 

 

I put Gigabit in quotes above as that is advertising Bravo Sierra. With the 2 antennas 6” apart, I could get ~650 Mbps thruput. I can, however get the same thruput 150’ away. I can get 450 Mbps thru a window, which oddly enuf, attenuates the link by 20dB. Either speed is plenty, though. Some folks claim a 9 mile path works with these devices. I would not plan on 650 Mbps at that range though.

 

So yah…You can run a RP-16 SDR remotely and connect it to the mothership via Wi-Fi, if you do it right.

 

73,

Ted

K9IMM

 

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