"Jack Painter" wrote in message
news:FoMee.897$It1.199@lakeread02...

"Dave Stadt" wrote

"Jack Painter" wrote in message
news:msAee.731$It1.406@lakeread02...

wrote

Gotcha, but I don't see why anyone would choose to power their
receiver
off such a battery. There are plenty of sealed lead-acid and gel
cell
batteries on the market that are safe for indoor use and that
produce
negligible emissions.

Steve

Hi Steve, I power two transceivers (1 VHF, 1 HF) off a 12vdc deep
cycle
battery, and the Drake R8B is powered from the computer's UPS. Other
radios
and tuners that can accept external DC get it from non-switching DC
power
supplies. Price was somewhat of an issue in a battery that is required
for
both normal and stand-by use, and the only reasonably priced deep
cycle's
were vented lead-acid types. Once a month I use a powerful charger and
only
in an outside vented area. But the 1 amp float charger produces very
little
gasses and would not overcharge unless left on for days with no draw
on
the
battery. For some very high operating temperature receivers such as
the
older Icoms, external DC is the only way to go, unless you can provide
constant air movement over the radios. It has zero effect in reducing
noise
in my opinion, but heat is the enemy of all electronics and definitely
shortens their lifespan. Unless the receivers have a narrow-band
stabilizing ceramic oven oscillator option, the receiver will drift
less
when external DC power is provided.

Jack Painter
Virginia Beach, Virginia


Reasonable heat is not a significant factor for modern electronics.
Humidity and moisture are more of a factor and heat lowers both. On/off
cycles are the most damaging.


I agree with that. And the Drake R8B for instance, produces very low heat
from it's internal transformer. Icom's R-7000, R-7001, R-71A and R-72 on
the
other hand, produce excessive transformer heat, and function much more
reliably and with assured improvement in longevity by using external DC.
Anyone who has worked on the above radios knows the latent damage to them
by
their normal operating temps, which are excessive for optimal performance.
There are kits to install cooling fans for them, or you can move air over
them by external fan, or you can operate DC. To each his own.

Jack


Or do what I did and dump the junk ICOM and buy an R8B. The R-71A was the
worst receiver I ever owned.