[aprssig] Solar BS (bulletin station)

[kliegle at myfairpoint.net]

I've run a solar powered WX digi for years. One thing I learned is that using a mobile rig for at a solar powered site costs you dearly in idle power consumption. Typical mobile rig draws more than 1A on RX, which a digipeater is doing quite a lot if in a quiet area. To get the equivalent ERP, I would use a higher gain antenna and if possible, a higher location (no ERP gain but better RX!)

 An HT on RX is much more efficient on idle power consumption.

Example:

Mobile rig RX 1A => 1Ax24Hr =>  24A-Hr per day

HT RX 0.150A =>  0.15x24Hr =>  3.6A-Hr per day



12V solar panels are typically about $1 per watt new, but I never buy new. They appear on Craigslist from time to time as people remove them from service, and can be had for very small money. Just be warned, the PWM solar chargers can wreak havoc on nearby HF operations. I have the Morningstar 30A PWM's, but cutting a jumper on the circuit board makes it a simple pulse type (on/off) and no birdies drifting up and down the HF spectrum!

As for batteries, the entire repeater system co-located at the site was solar powered as well. I had a bank of Sam's Club Golf Cart Batteries (6V at 225A-Hr) in series/parallel combination to get me 14V @450A-Hr of storage. Even on a cloudy day, the net gain into the battery bank was still positive. Winter, with the short daylight hours was the most critical time on top of the batteries stored in an unheated shed. I now have commercial power, but a few panels are still in use for backup charging incase I'm not around to fire up the whole house/farm generator.

73 Kriss KA1GJU
KA1GJU-X  X=INT(9)
 


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