Mobile base station radio

[Bernie[_3_]]

I'm interested in what others are using for mobile gound
communications set ups, as in chase vehicles used on long straight out
flights. Obviously, would like something reasonaly priced...read
cheap. Anyone using a handheld VHF transceiver with an external (roof
top) antenna?

[Bill Daniels]

I've got an old JRC 520 handheld and a 5/8th wave magnet base rooftop
antenna. It 'works' which is all that I can say for it. No one's commented
favorably on the transmit quality either. The real problem is the receiver
signal to noise ratio which is not descriminating enough to pull a weak
signal out of the background static. If I were going to really depend on a
crew radio, I'd get something better.

A lot of people now use cell phone SMS texting which is proving much more
reliable than cell voice calls or, in many cases, VHF air-band radio beyond
100 miles range. I'm thinking of that as a backup for a not so great crew
radio.

Bill Daniels


"Bernie" > wrote in message
oups.com...
> I'm interested in what others are using for mobile gound
> communications set ups, as in chase vehicles used on long straight out
> flights. Obviously, would like something reasonaly priced...read
> cheap. Anyone using a handheld VHF transceiver with an external (roof
> top) antenna?
>

[John Scott]

Our club uses a Icom IC-A6 handheld with a 5/8" mag mount whip as both a
base radio and a chase radio, if needed. When at our home field we have a
10' mast (standard length of galvanized pipe at Home Depot) with a ground
plane at the top. The whip antenna is simply "mag mounted" on the top if
the plate holding the ground plane elements. At camps, we use the top of a
convient car.

The Icom gives us the ability to monitor (scan) both the local unicom
frequency and 123.3. We have it rigged with an external speaker and hand
mic.

John Scott

[Burt Compton - Marfa]

Get the best antenna situation possible.
As any ham radio oldtimer will tell you, "It's in the antenna."

Try the 5/8 wave antennas from wingsand wheels.com

Find a ham radio enthuisast with a SWR meter and tune the antenna as
close as possible to a "Standing Wave Ratio" (SWR) of 1 to 1. Even a
handheld will work well with a proper antenna. The "rubber
ducky"antenna is convenient but inefficient.

So hook your handheld to a proper antenna. Keep the coax cable run as
short as possible.
Coax can be high loss, but open wire feeders are not practical.

Do all this, then think about a base station, but putting lots of
output power into an inefficient antenna is a waste.

Dad was a ham back when we used to go to the Nationals with his LK-10A
then later his Open Cirrus and store-bought antennas were unheard of.
Our crew antenna in the 1960's (and later) was a 24 inch (1/4 wave)
straightened coathanger mounted on a piece of tin - a large flattened
bean can - which we slammed into the top of the rear door of the
Plymouth wagon. Very short coax. Wire antenna.trimmed to one to one
SWR. It worked fine.

Work hard on the antenna SWR no matter how fancy your antenna might
be.

Then teach your crew to drive to the highest hill on course for best
reception (line of sight), hopefully with a nice shady tree and a
Dairy Queen, and to listen for you. Call them often - tell them
briefly of your progress (in code) and make them part of the flight.
Involved crews are happy crews.

Burt
Marfa, west Texas
USA

[Bill Daniels]

I always like what Burt writes. It's hard to argue with.

It's worth mentioning that we are talking about a technology that was
developed almost 100 years ago - two-meter band AM radio telephony. In
this age of the Internet, Cell Phones, SMS and IM communication, AM radio is
an artifact of a vanishing age.

I remember sitting on a hill in the Mojave Desert as far as possible from RF
noise sources like power lines and neon signs. We were listening to the
hiss of a vacuum tube reciever with the squelch wide open hoping for a faint
signal from a distant glider.

To burt's excellent advice I would add this. A carrier wave can be detected
at a far greater distance than a voice modulated signal. Clicking the mike
PTT button to send your contest number in Morse Code may well get through
when nothing else will. I recall copying down a repeated transmission of
contest number followed by an airport identifier. It told us all we needed
to pick up our pilot.

Hmm...I should mention that the old vacuum tube recievers had a feature
missing from modern devices - a BFO (Beat Frequency Oscillator). A BFO
generated a local signal which combined with the incoming carrier signal
created a "beat" or hetrodyne that could be heard as a tone. That made
hearing a CW code transmission easier.

Bill Daniels


"Burt Compton - Marfa" > wrote in message
oups.com...
> Get the best antenna situation possible.
> As any ham radio oldtimer will tell you, "It's in the antenna."
>
> Try the 5/8 wave antennas from wingsand wheels.com
>
> Find a ham radio enthuisast with a SWR meter and tune the antenna as
> close as possible to a "Standing Wave Ratio" (SWR) of 1 to 1. Even a
> handheld will work well with a proper antenna. The "rubber
> ducky"antenna is convenient but inefficient.
>
> So hook your handheld to a proper antenna. Keep the coax cable run as
> short as possible.
> Coax can be high loss, but open wire feeders are not practical.
>
> Do all this, then think about a base station, but putting lots of
> output power into an inefficient antenna is a waste.
>
> Dad was a ham back when we used to go to the Nationals with his LK-10A
> then later his Open Cirrus and store-bought antennas were unheard of.
> Our crew antenna in the 1960's (and later) was a 24 inch (1/4 wave)
> straightened coathanger mounted on a piece of tin - a large flattened
> bean can - which we slammed into the top of the rear door of the
> Plymouth wagon. Very short coax. Wire antenna.trimmed to one to one
> SWR. It worked fine.
>
> Work hard on the antenna SWR no matter how fancy your antenna might
> be.
>
> Then teach your crew to drive to the highest hill on course for best
> reception (line of sight), hopefully with a nice shady tree and a
> Dairy Queen, and to listen for you. Call them often - tell them
> briefly of your progress (in code) and make them part of the flight.
> Involved crews are happy crews.
>
> Burt
> Marfa, west Texas
> USA
>