I visited this website
http://www.icom.co.jp/world/products/marine/index.htm trying to find
out what is the distance that IC-M710 can communicate. I guess the
answer is it depends, can anyone tell me what is the typical distance I
can expect this unit capable of. The website tells me "A full 150 W
(PEP) of output power is available for reliable long distance
communication" but how long is long, really.

Thank you,

From the ICOM website -- the IC-M710
a.. Covers all allowed bands between 1.6 and 27.5 MHz
a.. But propagation varies on each band depending on night or day, time of
year, time in the sunspot cycle, solar storms, ground wave propagation, etc.

Suggest you read about propagation.
See URL:
http://www.ae4rv.com/tn/propflash.htm

Hope that helps.

CL
"Newbie" wrote in message
ups.com...
I visited this website
http://www.icom.co.jp/world/products/marine/index.htm trying to find
out what is the distance that IC-M710 can communicate. I guess the
answer is it depends, can anyone tell me what is the typical distance I
can expect this unit capable of. The website tells me "A full 150 W
(PEP) of output power is available for reliable long distance
communication" but how long is long, really.

Thank you,

Caveat Lector wrote:
From the ICOM website -- the IC-M710
a.. Covers all allowed bands between 1.6 and 27.5 MHz
a.. But propagation varies on each band depending on night or day, time of
year, time in the sunspot cycle, solar storms, ground wave propagation, etc.

Suggest you read about propagation.
See URL:
http://www.ae4rv.com/tn/propflash.htm

Hope that helps.

CL

Thank you Caveat.

When VOA or BBC plan to build a radio station, they must be able to
calculate the coverage of their station in 'normal' conditions.

When we talk about cars, you may say a Mercedes C200 speed depends on
road conditions, tires pressure, gas, temperature, etc... but surely
people can say it can do 100km/hr.

Don't we have something similar when talking about radios ?

In article .com,
"Newbie" wrote:

Caveat Lector wrote:
From the ICOM website -- the IC-M710
a.. Covers all allowed bands between 1.6 and 27.5 MHz
a.. But propagation varies on each band depending on night or day, time of
year, time in the sunspot cycle, solar storms, ground wave propagation, etc.

Suggest you read about propagation.
See URL:
http://www.ae4rv.com/tn/propflash.htm

Hope that helps.

CL

Thank you Caveat.

When VOA or BBC plan to build a radio station, they must be able to
calculate the coverage of their station in 'normal' conditions.

When we talk about cars, you may say a Mercedes C200 speed depends on
road conditions, tires pressure, gas, temperature, etc... but surely
people can say it can do 100km/hr.

Don't we have something similar when talking about radios ?


The problem with your analogy is that there are no "Normal" conditions
when it come to RF Propagation. One could "Generalize" that Ground Wave
Communications in the 2-3 Mhz Marine Bands is 100-300 miles, for a 150
watt Transmit signal and no local Receiver noise. BUT that would be
a VERY BIG Generalization and your milage WILL vary with all the
previously posted conditional changes. Another generalization would be
that the higher the frequency the shorter the Ground Wave Propagation.
Again, that is a Gross Generalization, and if you used that to determine
what frequency to use for an y particular communications path, you will
not communicate 50% of the time. Modern MF/HF System use ALE to
determine what bands are open for any two stations. This is done by
having each radio send breif test transmissions on specific frequencies
in each Band at specific times, and allowing the ALE software to select
the best SNR for each band at the distance between the two stations.
This is very expensive equipment, and not common in Marine
Communications, but very common in Military Communications. After you
spend some time on the bands, communicating between specific locations,
at various times of the day, and year, and thru various SunSpot cycles,
you will get better at determining what will work and what is a waste of
time. This is where MF/HF Commincations is more an ART, and not a
Science.

Bruce in alaska Long time Marine Radioman, in the North Pacific.....
--
add a 2 before @

"Newbie" wrote in message
oups.com...

Caveat Lector wrote:
From the ICOM website -- the IC-M710
a.. Covers all allowed bands between 1.6 and 27.5 MHz
a.. But propagation varies on each band depending on night or day, time
of
year, time in the sunspot cycle, solar storms, ground wave propagation,
etc.

Suggest you read about propagation.
See URL:
http://www.ae4rv.com/tn/propflash.htm

Hope that helps.

CL

Thank you Caveat.

When VOA or BBC plan to build a radio station, they must be able to
calculate the coverage of their station in 'normal' conditions.

The VOA and BBC transmit on several frequencies to have coverage because of
the varing propagation.

When we talk about cars, you may say a Mercedes C200 speed depends on
road conditions, tires pressure, gas, temperature, etc... but surely
people can say it can do 100km/hr.

Don't we have something similar when talking about radios ?

Not really, take AM Broadcast stations. During the day they cover a small
area. At night, this area is increased quite a bit. From wikipedia
http://en.wikipedia.org/wiki/AM_radi...ns_of_AM_radio
Medium wave and short wave radio signals act differently during daytime and
nighttime. During the day, AM signals travel by groundwave, diffracting
around the curve of the earth over a distance up to a few hundred miles (or
kilometers) from the signal transmitter. However, after sunset, changes in
the ionosphere cause AM signals to travel by skywave, enabling AM radio
stations to be heard much farther from their point of origin than is normal
during the day. This phenomenon can be easily observed by scanning an AM
radio dial at night. As a result, many broadcast stations are required as a
condition of license to reduce their broadcasting power significantly (or
use directional antennas) after sunset, or even to suspend broadcasting
entirely during nighttime hours. (Such stations are commonly referred to as
daytimers.)

In fact, at night during the winter time, big AM stations can be heard clear
across the USA. Not so during the day.

CL

"Newbie" wrote in message
oups.com...

Caveat Lector wrote:
From the ICOM website -- the IC-M710
a.. Covers all allowed bands between 1.6 and 27.5 MHz
a.. But propagation varies on each band depending on night or day, time
of
year, time in the sunspot cycle, solar storms, ground wave propagation,
etc.

Suggest you read about propagation.
See URL:
http://www.ae4rv.com/tn/propflash.htm

Hope that helps.

CL

Thank you Caveat.

When VOA or BBC plan to build a radio station, they must be able to
calculate the coverage of their station in 'normal' conditions.

When we talk about cars, you may say a Mercedes C200 speed depends on
road conditions, tires pressure, gas, temperature, etc... but surely
people can say it can do 100km/hr.

Don't we have something similar when talking about radios ?


There are modles that will give general predictions of how far the signals
will travel. They will give predictions such as the coverage like 50 % of
the time, 80 % of the time and so on. Outside of very local conditions such
as out to 5 or 10 miles anything can hapen. Sort of like a river near here.
Most of the time it is around 200 feet wide. I have seen it almost dry a
couple of years ago. Think I could have jumped over it if it was not for
the mud.

It all depends on the frequency , the ionospheric conditions and black
magic.
It is more like the gas milage of a car, It depends on how it is driven and
the state of the tuning. You can get a general idea, but not an exect
value.