Wednesday, September 13, 2023

Shack is off-grid again

Visiting the emergency communications exercise a few weeks ago inspired me to make sure my radio shack can operate without mains power if required. This could be important if this summer is a fire season as seems possible.

I had a folding solar panel claimed to generate 100W from the old days of my camper van.


For now it's on the ground but I may put it on the roof at a later date for more sun during the day.

I purchased a 105Ah flooded lead acid deep cycle battery for $249. As it's just sitting on the floor weight isn't a problem. 


A cheap Chinese PWM charger got me started and worked fine but I ordered a more efficient MPPT charger made by Renogy. It seemed to work well...


Unfortunately it generates a lot of radio noise. Even up on 20m it leaves bands of noise all over the dial.

The cheap Chinese PWM charger doesn't produce any noticeable noise. (You can see it mounted on the wall with the blue face plate above).


To be fair, my noise floor here is very low and I haven't tried to suppress the noise from the Renogy unit at all so far. It is disappointing though.

I powered my IC-7300 all night receiving WSPR last night and the battery was down to 12.3V in the morning. It is good to know that I can make radio contact after a long term power outage if required. It is a very useful feature of an Amateur radio station.

3 comments:

  1. Absolutely a thing I have in mind for my station here. I have a similair solarcharger as your tiny chinese one that doesn't give me any noise at all. However all my neighbours have solarpanels with optimizers which do generate a lot of noise. The picture you show of the waterfall is also very familiar for me. I got this on all bands. 73, Bas

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  2. Thanks Bas,

    It's a bit uncommon to find the cheap Chinese device performs better in this case.

    73

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  3. Not really so strange.
    There is a tendency to MPPT controllers being much more noisy than (cheap) PWM controllers. I tried one as well for my system, and sure enough, the cheap PWM controller is fine, the MPPT is noisy.

    Vy 73 de OZ9QV, Jan

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