FedEx delivers on the 27th and I will be able to size it up then. First I realize that 28V supplies are scarce but I have no need of one, I do need a good 25A rack supple for a GE MII 6 meter repeater that is going to be improved shortly. I like the idea of using the 220 input to lower the voltage. That was something I had not thought of. The conversion of the board and crowbar circuits are not a problem. If any one wants to swap an equivalent rack mount for the unit I am great with it.
Charles, NM4V --- In Repeater-Builder@yahoogroups.com, "Eric Lemmon" <wb6...@...> wrote: > > Charles, > > You can't "convert" a 28 VDC Astron power supply to a lower voltage, unless > you replace the power transformer and regulator board, and possibly the pass > transistors. Since the Astron linear power supplies use a series-pass > regulator design, the pass transistors could burn up if expected to regulate > at full design current but at half the rated voltage. That said, you CAN > install a 14 VDC regulator board (or modify the 28 VDC regulator board with > components suitable for 14 VDC) and run the power supply at less than half > its rated load. I would never do this, because the value of a good, > high-capacity 28 VDC power supply is always much greater than one that has > been hacked to operate at a lower value. > > Before you decide what to do, call Fred (the Tech Support guru at Astron) > and ask his advice. Go to the Astron web site for the phone number. > > 73, Eric Lemmon WB6FLY > > --- In Repeater-Builder@yahoogroups.com > <mailto:Repeater-Builder%40yahoogroups.com> , "Charles Lowery" <clowery@> > wrote: > > > > I purchased a Uniden 28 volt power supply today on ebay. It lookes like > the Astron LSRM-25A or 35A both front and back (I assume Astron made it). > Without seeing it, I assume it works OK (cost $2.00 + shipping). Has anyone > converted one of these to 12 volts? I have no schematics for it and can not > find one on the net. If converted what would be the available current? > > > > Charles, NM4V >
