I recently built a solar / lifepo battery system for my WSPR receive setup. I massively overestimated the amount of power needed, especially after removing a small computer from the remote setup. I have so much unused power capacity at the electric WSPR outhouse that I would like to use the excess to power a ZachTek Desktop transmitter placed in a waterproof enclosure ... maybe as far as 100 meters away. Not being the most the technically sophisticated ham (my degree is in History), I'm trying to figure out the best way to do this. Run 12v on fairly heavy wire to the remote site and step down to 5v there? How far can I get away with by stepping down at the power block and simply using a long USB cable? (The internet is full of contradictory answers on the latter option.) Has anyone done something similar and/or have suggestions on how to do this reliably?

Taking into account the invitation to "show off", I will document my first very simple WSPR project: To make an inexpensive solar powered WSPR beacon that will operate autonomously and off-grid for an indefinite time. The idea was to rely on cheap off-the-shelf parts and, where possible, materials at hand. The ingredients: Zachtek Highplus desktop WSPR transmitter "Sockitbox" waterproof box, medium (Amazon, previously returned, US$17) Voltaic Systems V25 6400mah battery back - pass though/ "always on:" (Amazon, $29) Renogy 10 watt 'rugged' solar panel (Amazon, $19) Assorted cables, on hand. To prevent them from getting banged around, I used velcro (on hand) to secure the battery pack and transmitter to the bottom of the box. The 10 watt panel should be more than enough, even through the winter. 5 watts might have been sufficient. I made one mistake. I initially bought a much cheaper battery pack ($12) that the seller claimed had "pass through charging" (meaning it would charge and power the transmitter simultaneously). In fact, it did not work reliably and would periodically stop powering the transmitter while the solar panel was attached to it. It had to be replaced with the more expensive "always on" pack. One aggravation is the design of the top of the waterproof box which, inexplicably, allows water to pool on it. This is easy to remedy, however, by placing a plastic sheet on top of it. (And the solar panel on top of the sheet.) One weakness is the USB connection to the solar panel, which is exposed, and which I have heavily taped up. For the moment I have a fabric covered USB cable, which obviously might wick moisture into the box. But I am pretty sure I'll eventually find a plastic jacketed cable lying around the house, and will change it out when that happens. Right now I have an RG8X antenna feed line that is too long. I found a shorter piece of LMR-400 in my "assorted junk" bin. It even has SMA on one end, but it has an N connector on the other. It's a well made cable, though, so I don't want to cut into it. So I've ordered an N female to male PL-258 adapter for the antenna line. The antenna itself is a horse fence antenna with elements for 10 meters. I am broadcasting on that and 6m. Reception reports received on 10 meters up and down the US East Coast, and out to several mid-west states. Only one 6m reception report so far - but it was from over 700km away. So the signal is getting out ... I just don't think many folks are listening on that band. The goal here is for this transmitter to continue working indefinitely, without any intervention from me.