Hi all,

You may recall me mentioning I was thinking about adapting a 24V PSU
for use at 13.8V for powering up mobile HF rigs and stuff. I had some
spare time yesterday and took this thing to bits for a better look
inside. It turns out the mains transformer has several secondary
tapping points. I discontected the DC-stab/reg side of the supply
circuitry and reconnected the secondary tapping points to lower voltage
tappings.
Now I measure 16.8V after the transformer's output has been rectified
and applied across the *big* electrolytic. This is under no-load
conditions. Now, is that 3V enough 'headroom' to use up in regulation
and stabilisation for 13.8V final output if I throw the old 28V
reg/stab away and build something from scratch? There are 6 pass
transistors plus a driver (2n3055) already mounted which I plan to use
in the adapted version, so basically I'll just junk the existing
control board and re-use everything else. Any observations/tips?
Thanks,
P.