Woo Hoo! That was easy!

`Got the kit today. Built it up into an old ADS-B kit enclosure. Works like a charm just sitting on the ground. Will be rebuilding antenna and hardware into a fully enclosed 6" square ABS NEMA box next weekend, but this will work for now.

I’m impressed!! You certainly did a fine job packaging the hardware. All you need now is a waterproof antenna. Ken

This is really neat and tidy. I’m surprised you’re not seeing any interference issues. No packets loss (though small sample size). Are you leaving it on all of the time?

Yes, it’s been running continuously, minus me futzing around with the network settings. I plan to leave it on 24/7. I think I finally got it to settle down and work OK on WiFi channel 1. Was having lots of problems with interference.

Next on the to do list:

  1. rebuild into a slightly larger enclosure (Bud model 32010 http://www.alliedelec.com/bud-industries-nbf-32010/70148200/ ) which will accommodate the antenna in the lid, and room in the bottom for a rather awesome aluminum heatsink for the RTL:


  1. Incorporate a USB hub to accommodate a wireless dongle, the RTL and a 32GB flash drive

  2. Build the preamp into a metal canister for better shielding

  3. Put the C.H.I.P. into a Zebra case for protection

  4. install a POE converter to allow powering it over CAT5 for long distances. This would also allow using more efficient high voltage solar array as well.

  5. Small fan and splashproof vent

Questions:

I’d like to put in a USB WiFi card with antenna port to allow connecting to a high gain WiFi antenna. Any idea of one that would be supported?

Any thoughts on using a lower power RTL? The 820T devices are power hogs.

I’m pretty happy with how it’s working now. Pointing out the window, I get between 3.6 and 5.3 SNR

What do you mean by low power RTL? I believe the R820T2 is the only compatible tune at this point.

It seems the RTL-SDR dongles dissipate a lot of heat, i.e. wasted power. The specifications are sketchy on these things, in other words, very difficult to find actual power requirements. I’ve seen claimed power consumption of 150ma up to 600ma around the hobby forums. I suppose I’ll have to break down and actually measure it :slight_smile: That said, I just wonder if the Nooelec Nano dongles might use less power? They seem to be the same chipset, so I’m not sure how they crammed all that onto the smaller dongle, unless they just used both sides of the PC board.

Anyway, just a thought. Trying to get closer to a system that could be powered by a small solar panel, and still have enough to charge a battery for overnight reception.

Playing with parts placement in the new box. Not sure exactly why, but I get about 2db better SNR with this setup in the same location. Not sure if the heatsink is helping the RTL or what.

I think it’s because all of the components are placed under the antenna, which is outside of its side lobes.

I’m interested also in the low power SDRs you reference…

Checked the system, all up and running with the CHIP, the LNA, a USB hub with the RTL-SDR and a 32GB flash drive plugged in, and it draws just about 1A (varies between about 800mA and 1100mA). Not as much as I anticipated it would be.

Still need to find the solution for getting a WiFi dongle to work.

I have a AusPi 802.11N dongle which is Ralink based like the Tenda, and has an antenna port, which I want to use for an external WiFi antenna on the box, but it didn’t seem to load when booting the CHIP, so that will have to wait for drivers or some different code I guess.

I would be curious to know of the Nooelec Nano dongles are about the same draw as this one, or significantly less. I suspect they are probably about the same. Anyone using a Nano for anything?

The NooElec Nanos actually use more power between all of the nano sized dongles.

Here’s a comparison between two types of nanos that I did: http://imgur.com/a/WOIOo

The NooElec uses a bit more power and has significantly worse heat distribution on the board.

This is the “nano” SDR that I produce (labeled “Stratux”): http://www.rtl-sdr.com/wp-content/uploads/2016/11/stratux_compare.png. They main goal in making these were for my project, which is a mobile device and runs off of a battery – lowering power consumption was the main concern.

You’ll see that the noise floor is much higher on the low end, but at 1.5 GHz, my dongle is about similar in noise floor to the RTL-SDR one. The noise spurs are still there, so that might be an issue.

If you want to try it, I’ll send you one for for free. [email protected]. Would be curious to see a side-by-side comparison in your setup. Remember that there is no bias tee in a standard dongle (even the NooElec ones you’re talking about), so you’ll have to power the LNA by some external source (are you doing that now?) if you plan to try another setup.

And here we are with the POE installed, and weatherproof RJ45 connector. This will make it easier to power over long distance, whether outside or inside, and allow the addition of a Ethernet adaptor or USB hub with Ethernet if desired.

Also shrunk the RTL-SDR heatsink and added some heavy duty foil shielding to the LNA, as this model seem to lack the shielding that the Nooelec and other similar amps have. Not sure if that will make a difference, but it can’t hurt.

Next steps:

  1. Design a ventilation system for passthru convective cooling. I have some ideas along the lines of a splashproof “snorkel” of sorts.

  2. Design a pole mount with adjustable angle.

  3. Figure out how add drivers or otherwise enable the use of the AusPi WiFi dongle or similar that has external antenna port. Mount WiFi antenna port and antenna to bottom of box.