[Elecraft] Solar Panels

[Craig D. Smith]

<> I'm interested in using solar panels to power the K2 for emergency/field
day
<> operations and am wondering what sort of experience others have had.  

I have had very positive results using a solar panel, Douglas.  

I also have a K2 and a solar panel with rechargeable battery is my main
power source for it.  I am using a normal 7 AH sealed lead acid battery
which resides in the shack.  I have a "10W" solar panel.  It is a very nice
high quality unit made by BP which I bought over the internet for about
$125.  This matches up nicely with the 7AH battery and the K2 current draw.
I use a Don Brown charge controller which I built from one of his kits.  I
can highly recommend this also (no connection to either).  If you search the
Elecraft reflector for "Don Brown" and/or "Charge controller" you should
come up with info about ordering the kit - as I recall it was only about
$25.  It will allow charging from either a modest size solar panel or from a
power supply.

The solar panel puts out about 650 mA in full sun which is about the desired
upper limit of the charge rate for this sized battery.  The wiring between
the panel and the battery is non-critical - I use AWG18 - since the current
is limited and you don't care about voltage drop since the open circuit
output voltage of the panel is over 16V.

I used this setup on Field Day this year but with the K2 turned down to 5W.
The battery kept me going all night and the solar panel took over and
refreshed things on Sunday.  The setup does work - even for contests.

Let me know if you would like more info

        73
               .... Craig   AC0DS