Solar Powered WSPRLite “Beacon”

One of the things I enjoy sharing with the amateur community, are WSPR antenna tests from the field. Now imagine that we place a WSPRLite in the field above the Arctic Circle, with one of our favorite antennas. A waterproof case, light-weight dolar panel, small USB battery pack to power at all. Wouldn’t that be cool? 

At the time I started writing this post, I’ve already been testing for a week, week and a half or so. I pulled a Goal Zero Guide 10 and Nomad 7 solar panel from the junk box, for some proof of concept testing. The Guide 10 Plus is a combination AA battery pack, and 7 watt solar panel, which can simultaneously be charged and discharged. The Nomad 7 solar panel can be daisy-chained  with other Nomad 7 panels , to increase  solar collection.
I know a 4 AA pack and 7 watt panel are not a lot of power.  However, we do benefit from Midnight Sun at 65 °N right now, do it might be enough for the tests. I started each day running the WSPRLite in my backyard a few hours aT a time. I tweaked the beacon intervals to increase the battery life and eventually on 7-9 June 2017, was a to run the WSPRLite just shy of 2 complete days. Not bad for a toy charger and solar panel.

The Goal Zero Guide 10 worked out to be a nice companion for the WSPRLite. The stand-by current draw of the WSPRLite is 0.05A and 0.14A on TX. This means actually The Nomad 7 solar panel could power the WSPRLite itself, provided it was always in full sunlight. Unfortunately the Earth and Sun are moving targets. That’s where the small battery pack comes in.

There are a few ways to achieve functionality, when the sun isn’t pointing at our solar panel. 

  • Collect more sunlight by using a larger solar panel
  •  Use a second identical solar panel to cover more of the sky.
  • Increase battery capacity
  • Any combination of 2 of the above.

Problems I ran in to.
Actually the reason I used the Guide 10 battery pack, was it’s small size, and two unique charge ports. It’s got one port for the solar panel, and a second USB input. Both are meant for charging. Either of these ports can be used to charge the Guide 10, however using the solar port on the Guide 10 will disable output to the USB output port. So the Nomad 7 solar panel or whatever USB solar panel used, must be plugged into the USB input on the Guide 10. Connected this way the Guide 10 will continue to provide Power for the WSPRLite, while simultaneously being charged from a solar panel. This is an undocumented “feature” from Goal Zero.

So I extended my test to Anker Series USB battery packs. Some of these packs cannot detect the WSPRLite, since it draws such small current. Also some of them will shut off power to the USB output if there’s power applied to the USB input.  I was lucky enough to have a couple of these packs in the house which were compatible with the Nomad 7 solar panel and WSPRLite.

WSPRLite wish list
If you’ve been around the channel for a while you’ve seen the Mobilinkd kiss TNC from time to time. Personally I wish our little wspr beacon had an internal battery like our Mobilinkd kiss tnc. This way I could simply plug in our little Beacon to a USB solar panel, to charge its own internal battery. This would make the WSPRLite much more practical for field testing. Perhaps it’s time to take it apart and do some ” re-engineering”.

I know what you’re thinking, more crazy ideas from Julian!  the point of making this test and putting a kid together, is to test our antenna systems out in the field. I certainly would not like to stay out in the field for 30 days, just to test an antenna. Okay I would, but it’s not practical. Setting up a self-contained waterproof system that will simply run once activated, isn’t necessarily a bad idea.
I’m going to keep on testing getting this to run longer and once I’m satisfied that it will run for at least 5 days, I think we’ll take a trip to Lapland, to set one up.

de oh8stn

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