Re: Handheld Nav/Com suggestions?

[Ross Oliver]

The OTHER Kevin in San Diego <skiddz*AT*adelphia*DOT*net> wrote:
>I'm kinda leaning towards the ICOM A23 for what I think may be a
>"silly" reason. NiMH batteries. I'm not at all keen on carrying
>alkalines with me all the time and I've seen 1st hand the "memory"
>problems inherent with NiCd batteries. The small size and weight are
>pros as well.


If you will be using the radio and charging the batteries regularly,
then NiMH is a good choice. However, if you plan to throw the radio
in your flight bag and expect it to work six months from now (especially
for transmitting), the NiMH batteries will have long since self-discharged.
Alkalines have a long shelf life, but are heavier, and the A23 at least
will not transmit at all when powered by alkalines.

After lots of experimenting with the A23 and different battery combinations,
I finally chose the Sportys SP-200 powered by photo lithium AAs. A
full set of eight costs about $20, but they have a long shelf life,
and are about half the weight of alkalines. My SP-200 with lithium AAs
weighs about the same as an A23 with a set of alkalines.

Other advantages of the SP-200 over the A23:

- The 8.33 khz channel spacing, as you already noted. Like the
changeover from 360 to 720 to 760 channels, this change will
happen gradually over time, with the newer frequencies being assigned
to services like ASOS, ATIS, clearance delivery, etc. The SP-200
will extend the life of my aircraft radio by allowing me to
access these new frequencies.

- The A23's CDI is so TINY as to be unusable.

- The A23 will receive the audio of localizer frequencies, but the CDI is
non-functional. The SP-200's CDI will work on localizers.

- I don't like the recessed keys of the A23.

The one aspect of the A23 I like over the SP-200 is the ability to
use one of the knobs to dial a VOR radial. The SP-200 requires the
desired radial be entered via the keypad.

Before you make your choice, beg, borrow, or steal (temporarily) the
handheld you are considering, and take it for some in-flight trials.
It always amazes me how many people carry handhelds for "emergency"
use, but have never once taken them out of the bag in flight.
What is its range in your aircraft? Does it work with your headset?
How easy/difficult is it to work the controls while flying the plane?


Happy landings,
Ross Oliver

[Greg Copeland]

On Mon, 13 Sep 2004 06:07:43 +0000, Ross Oliver wrote:

First, let me say great comparison. I googled for this very topic and
stumbled on this thread. So, thanks!

Second, I'm sorry to jump in, but I didn't think you would mind.

[snip]
> If you will be using the radio and charging the batteries regularly,
> then NiMH is a good choice. However, if you plan to throw the radio in
> your flight bag and expect it to work six months from now (especially
> for transmitting), the NiMH batteries will have long since
> self-discharged. Alkalines have a long shelf life, but are heavier, and
> the A23 at least will not transmit at all when powered by alkalines.
>

Why would the A23 prevent someone from transmitting when using alkalines?
Most nicads only put out 1.2 volts. Really nice nicads will put out ~1.25
volts, but tend to be very expenseive (for batteries) and much harder to
find. An alkaline puts out 1.5 volts. The difference in power may
make the difference between transmitting at full power (5 watts) and
transmitting at something much less.

Also, power density for alkalines is normally much higher than what you
typically find for nicads. Which means, generally speaking, a set of
alkalines will last longer when it's in use; though clearly I am making
some assumptions here. And, as you rightly pointed out, a set of
alkalines can last a very long time in a flight bag. Whereas, a set of
nicads will be almost fully discharged within 30-60 days; again, depending
on your batteries.

Alkaline batteries also slowly discharge, whereas, nicads act like they
jumped off a cliff when nearly discharged. This means, with a set of
alkalines, you can usually pick and choose when you want to change your
batteries. Not to mention, you'll generally know when it's time. With a
set of nicads, you may be transmitting fine one second, only to find that
your batteries are completely dead the next.

Long story show, your comment struck me as odd. Is the transmission
limitation built into the radio's electronics or did it come from a
personal observation? What's the basis for your comment?

Thanks in advance,

Greg