@KF0AWL
Solar Controller
I had no idea what the famous Blue controller is you referenced. I personally use Renogy PWM controllers and have zero problems with RFI. One handles SLA and two newer versions handle lead acid batteries as well as Lithium. Instead of spending extra money on an actual MPPT controller, I used it toward another 100W flexible panel. Depending on the rating of the controller, they can typically handle multiple panels when wired correctly and 9~10 Amps is nice in a best case scenario using two panels. ( Note: Some controllers labeled MPPT are actually PWM. Read further on the description on that link. Still, I could be wrong. )
Solar Panel
I mostly use flexible and folding, they are in great shape and still kick out plenty of power due to the occasional use. Additionally, I store and transport the 100W flexible panels in the boxes they shipped in, after removing the other support material inside. When I deploy the flexible panels, I put the cardboard box under them when on a flat surface such as my hot vehicle roof. This keeps the temperature down on the panels and improves longevity and power output. During the course of the day my panels are in three positions to track the sun. That has worked well enough for me.
Power Output
My flexible 100W solar panels will give me 4.5~5 Amps in full sun. My 50W folding panel does about 2.8 amps maximum after using several meters to confirm. Still, there's going to be some give and take between panels and when used due to clouds etc. I measured using an inline meter as well as a DC clamp meter simultaneously. Still, not all 100W panels are the same.
Where to begin
You could start out with a PWM controller and a single 100W panel whether folding or flexible. If you figure 4.25 amps charge current on the safe side, it would handle the RX amp draw and still put some charge back into the battery. Figure two panels giving you 8.5Ah minus 2A for the RX draw and you would enjoy 6.5 Amps charge, or say 6 Ah to play it safe.
The next step
Everyone should consider the power draw of their radio at different power levels and the actual dB gain. I recommend testing at 20, 40, 80 and then 100W while noting the amp draw. Then look up the actual dB gain difference between those output watt settings. The point here is the power saved and whether a single 100W panel will do the job, or if one needs two or more. I often use 20W and may step it up to 40W at times, or 80W if I really need to make a particular contact.
The more important part
An efficient antenna is critical. Consider the power draw of using 100W and a poor performing antenna, versus 20W with an efficient one. You see, your endeavor actually starts here. Still, some operators don't want to think about it and want to slap 100W through their antenna no matter what. Some antenna manufactures make accessories like a loading coil that will handle the 100W power which mostly dissipates the heat versus providing equal gain per watt. Those operators are having fun and there's nothing wrong with that as far as they are concerned.
Anyways, my advice above has phone use in mind. If you are using digital modes one would typically TX using lower power. Still, an efficient antenna is the most important part regardless of mode.
@prcguy - I would like to know more about, or a link to that 120W complete system for $119 shipped. That sounds fantastic!
