Boosting ICOM IC-A23 Handheld Aviation Radio

In article , CHANGE USERNAME TO
westes wrote:

I recently purchased an ICOM IC-A23 radio, and I'm disappointed in its
pickup. It gets the weather channels fine, but the reception for both the
airport and airplane radios is poor. Aside from standing next to the
airport or being right under the airplane, do I have any options for
improving gain and the quality of reception? Is there some third party
antenna that I could attach to this radio? It looks like it takes a
standard BNC type connector for the antenna that comes with it.

If you are on the ground, outside the airplane, you can purchase a
metal, 5/8 wave, telescoping antenna to replace the standard rubber
duckie.

Don't forget, VHF is line of sight. On the ground, you won't get much range to
another ground station regardless of how good your antenna is.

EDR wrote:

In article , CHANGE USERNAME TO
westes wrote:

I recently purchased an ICOM IC-A23 radio, and I'm disappointed in its
pickup. It gets the weather channels fine, but the reception for both the
airport and airplane radios is poor. Aside from standing next to the
airport or being right under the airplane, do I have any options for
improving gain and the quality of reception? Is there some third party
antenna that I could attach to this radio? It looks like it takes a
standard BNC type connector for the antenna that comes with it.

If you are on the ground, outside the airplane, you can purchase a
metal, 5/8 wave, telescoping antenna to replace the standard rubber
duckie.

--
--Ray Andraka, P.E.
President, the Andraka Consulting Group, Inc.
401/884-7930 Fax 401/884-7950
email
http://www.andraka.com

"They that give up essential liberty to obtain a little
temporary safety deserve neither liberty nor safety."
-Benjamin Franklin, 1759

Ray Andraka wrote:

Don't forget, VHF is line of sight. On the ground, you won't get much range to
another ground station regardless of how good your antenna is.

five miles is pretty good. And, since ZLA Catalina's RCO is atop a mountain on the
island, 40 miles works with ease.

EDR wrote:

In article , CHANGE USERNAME TO
westes wrote:

I recently purchased an ICOM IC-A23 radio, and I'm disappointed in its
pickup. It gets the weather channels fine, but the reception for both the
airport and airplane radios is poor. Aside from standing next to the
airport or being right under the airplane, do I have any options for
improving gain and the quality of reception? Is there some third party
antenna that I could attach to this radio? It looks like it takes a
standard BNC type connector for the antenna that comes with it.

If you are on the ground, outside the airplane, you can purchase a
metal, 5/8 wave, telescoping antenna to replace the standard rubber
duckie.

Right, I think my antenna is 5/8 wave. Makes it awesome with a roof mount.

How tall was that telescoping antenna?

Does anyone sell an off the shelf 5/8 wave telescoping antenna with a strong
magnetic base?

--
Will
westes AT earthbroadcast.com

"EDR" wrote in message
...
In article , CHANGE USERNAME TO
westes wrote:
If you are on the ground, outside the airplane, you can purchase a
metal, 5/8 wave, telescoping antenna to replace the standard rubber
duckie.

In article , CHANGE USERNAME TO
westes wrote:

How tall was that telescoping antenna?

I do not remember how long it extends to.
IIRC, the formula is 468/f(MHz) gives the wavelength. Multiply by 5/8
to get the antenna length in feet. For 123.0 MHz (middle of the band),
the length is 28.5 inches.

Does anyone sell an off the shelf 5/8 wave telescoping antenna with a strong
magnetic base?

Just purchase a standard ham 2m mag mount antenna and cut a piece of
stainless steel rod that fits the mag mount to the above calculated
length.

I disagree with the method described below for calculating a 5/8 wavelenth antenna.
As I recall, the formula you have below gives you the length in feet of
a half wave length antenna (not the full wavelength as you suggest). So a 5/8 ths
wave antenna would be twice as long as you calculated. Also, if you took a 2 meter
5/8's wave antenna, you'd need to lengthen it (not cut it down) to use it as a 5/8 wave
antenna on 123 MHz.
You probably could take a 5/8 wave 2 meter ham antenna and cut it down to a 1/4 wavelength
antenna for use on 123 MHz. The length for that would be somewhere around 22.89 inches.
Max T, CFI (and ham radio operator)



EDR wrote in message ...
In article , CHANGE USERNAME TO
westes wrote:

How tall was that telescoping antenna?

I do not remember how long it extends to.
IIRC, the formula is 468/f(MHz) gives the wavelength. Multiply by 5/8
to get the antenna length in feet. For 123.0 MHz (middle of the band),
the length is 28.5 inches.

Does anyone sell an off the shelf 5/8 wave telescoping antenna with a strong
magnetic base?

Just purchase a standard ham 2m mag mount antenna and cut a piece of
stainless steel rod that fits the mag mount to the above calculated
length.

You probably could take a 5/8 wave 2 meter ham antenna and cut it down to a 1/4
wavelength
antenna for use on 123 MHz.


There's more to it than that. The impedance has to match. For a 1/4 wave
antenna, all you need is 1/4 wave worth of metal. But for a 5/8 wave, you need
a coil at the bottom too, so that the antenna looks like 1/4 wave to the
transmitter, and works like a 5/8 wave to the ether. A ham band (or any other
band) 5/8 wave antenna will already have the appropriate coil, but if you
change the length significantly, the coil will no longer be the right value.

For 123 MHz the difference is probably not all that much, but it might be
enough, depending on your transmitter.

Jose

--
(for Email, make the obvious changes in my address)

"Max T, CFI" wrote:

I disagree with the method described below for calculating a 5/8 wavelenth antenna.
As I recall, the formula you have below gives you the length in feet of
a half wave length antenna (not the full wavelength as you suggest). So a 5/8 ths
wave antenna would be twice as long as you calculated. Also, if you took a 2 meter
5/8's wave antenna, you'd need to lengthen it (not cut it down) to use it as a 5/8 wave
antenna on 123 MHz.
You probably could take a 5/8 wave 2 meter ham antenna and cut it down to a 1/4 wavelength
antenna for use on 123 MHz. The length for that would be somewhere around 22.89 inches.
Max T, CFI (and ham radio operator)

EDR wrote in message ...
In article , CHANGE USERNAME TO
westes wrote:

How tall was that telescoping antenna?

I do not remember how long it extends to.
IIRC, the formula is 468/f(MHz) gives the wavelength. Multiply by 5/8
to get the antenna length in feet. For 123.0 MHz (middle of the band),
the length is 28.5 inches.

Does anyone sell an off the shelf 5/8 wave telescoping antenna with a strong
magnetic base?

Just purchase a standard ham 2m mag mount antenna and cut a piece of
stainless steel rod that fits the mag mount to the above calculated
length.

I had mine cut for 128.0 MHz to optimize the VHF voice band. The nav frequencies are less
important. Ham Radio Specialists in San Diego cut it, and had stock to do 5/8 wave length at
that frequency. The whip is much longer than 28.5 inches; somewhere around 40 inches, or so.

CHANGE USERNAME TO westes wrote:

How tall was that telescoping antenna?

Does anyone sell an off the shelf 5/8 wave telescoping antenna with a strong
magnetic base?

Whatever 5/8 of an RF wavelength of 128.0 MHz is; somewhere around 3 1/2 feet,
or so.

No one sells them off the shelf, because they can cut one for you in about two
minutes. Any decend ham radio store has all the stuff.