On 18/12/13 7:37 AM, The Simpsons
wrote:
The only problem with almost all nominal 12 volt radios,
is that the power out will drop to about half the maximum
when the applied voltage drops to about 12.5 volts. I run
mine mobile exclusively and when stationary with the engine
off, the power out drops to the expected 50 Watts. Not a
problem for me and I just use it. Does this mean it¡¯s crap?
I don¡¯t think so. My FT100 did this as well but again why
worry? It¡¯s only half a nominal S point and no one will
probably notice that! Probably my previous mobile radios did
as well but I didn¡¯t check them so never worried about the
power out when the engine wasn¡¯t running. My only worry was
discharging the battery to the point the engine would not
start!
Once the battery voltage on load drops too low then there
will be instability showing up as poor audio quality
(assuming SSB) and the battery needs charging.
If really worried about the drop in power, buy one of the
battery boosters that go in line with the radio power feed
to maintain 13.6 volts at the radio. You can then run your
radio at the full 100 Watts out until the battery is
completely flat. It will also compensate for poor battery
wiring and any other small losses.
Seems to me we are all worrying too much about what
doesn¡¯t matter too much really. It would be nice if the
power out was stable over the full battery voltage range but
it isn¡¯t. Maybe if the manufacturers fitted a battery
booster/ stabiliser within the radio and advertised the full
power out right down to maybe 10.8 volts, then they would
increase their sales.
I simply use the solar panel, which makes my overall power budget
positive and keeps the battery voltage reasonably high during Tx
(not as good as an alternator in a car, but good enough).? I ran the
IC-7000, a TM-G707A and a Macbook Pro (with DC-DC converter) on an
all day public service exercise.
--
73 de Tony VK3JED/VK3IRL
