[Waverley ARS] reduce battery voltage

[Edwin Lowe]

Hi guys, here's a technical problem I need some help with.

I have a couple of single use batteries rated about 28v, sitting around 
looking for use.  Problem is that I need to drop the voltage to 13.8v - 
12v for portable ops.  I could go to Jaycar and buy a gadget to do it 
for about $20 or so, but I don't know if that's worth the money for a 
couple of disposable batteries.

Does anyone have a cheaper suggestion for a circuit for hombrewing?  (or 
is it cheaper to buy the gadget?)  Thanks
Edwin

-- 
Edwin Lowe
VK2VEL
Sydney, Australia
ph:0407416090