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

[Ted Gisske]

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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