"Dave Platt" wrote in message
...
In article ,
Richard Harrison wrote:

Off topic, but you can`t power an antenna without power to the
transmitter.

I`m looking for a d-c to d-c converter that takes 28 volts on the input
and supplies 12 volts on the output. Up to 8 amperes may regularly be
drawn from the supply. That`s about 100 watts.

I need it now. That`s why I`m imposing on this group. There is no more
knowledgeable group to ask that I know of. I don`t have time to build
anything, though I`ve built such inverters and converters.

Check with Vicor (www.vicr.com). They make a whole range of DC-to-DC
converter modules.

Example: their V24B12C200B converter module takes 18-36 volts in, 12
volts out (programmable from 10% to 11% of this, so you could get 13.2
out), efficiency 85%, 200 watts output. Current limit is 17 amps
minimum, 19.2 amps typical.

I suspect, since 'up to 8 amperes may be drawn', that
he'll have a hard time meeting the '17 amps minimum'
spec...
__
Steve
KI5YG
..