Joey wrote:
Hi,
I'm trying to determine if I could use 10 meters to contact a station
about 75 miles away with about 2500ft elevation of a couple sets of
hills in between with just simple antennas on either end. Perhaps a
10m dipole on one end and some kind of stealthy one on the other. I
assume this would have to be ground wave only given the distance and
current band conditions.
My parents are both techs so we're currrently limited to parts of 10m
as the lowest band and I'd like to have something reliable without
need repeaters for disaster comms. We actually only have a few single
hop VHF/UHF repeaters between us, though quite a few linked ones.
I've also thought of 6m due to smaller antenna requirements, but I'm
pretty sure this is too far...
Thanks!

Just off-hand, I would suspect for reliable and consistent
communications a three element yagi and ~100 watts on each end would
result in enjoyable rag chews ... same for 6m.

Height? More the better.

Seventy-five miles on omni antennas is very chancy, in my humble
opinion. But then, power/height would be the main variables, enough
height and power would certainly help.

Regards,
JS

On 28 Apr, 09:55, John Smith I wrote:
Joey wrote:
Hi,
I'm trying to determine if I could use 10 meters to contact a station
about 75 miles away with about 2500ft elevation of a couple sets of
hills in between with just simple antennas on either end. Perhaps a
10m dipole on one end and some kind of stealthy one on the other. I
assume this would have to be ground wave only given the distance and
current band conditions.
My parents are both techs so we're currrently limited to parts of 10m
as the lowest band and I'd like to have something reliable without
need repeaters for disaster comms. We actually only have a few single
hop VHF/UHF repeaters between us, though quite a few linked ones.
I've also thought of 6m due to smaller antenna requirements, but I'm
pretty sure this is too far...
Thanks!

Just off-hand, I would suspect for reliable and consistent
communications a three element yagi and ~100 watts on each end would
result in enjoyable rag chews ... same for 6m.

Height? More the better.

Seventy-five miles on omni antennas is very chancy, in my humble
opinion. But then, power/height would be the main variables, enough
height and power would certainly help.

Regards,
JS

Hmmmm. I would think that going to a frequency such as 144 MHz would
be the way to go as radiation would tend to hug the earths
surface.With 28 MHz the height factor not only be impracticable (point
to point) but no amount of extra power is going to lower the TOA. When
my son was in a hospital over 100 miles away he used his hand held to
a local repeater and I used 10 watts with a directional antenna to the
distant repeater with intervening land less than 100 foot elevation
variance. Contact was always assured.
Art

art wrote:

...
Hmmmm. I would think that going to a frequency such as 144 MHz would
be the way to go as radiation would tend to hug the earths
surface.With 28 MHz the height factor not only be impracticable (point
to point) but no amount of extra power is going to lower the TOA. When
my son was in a hospital over 100 miles away he used his hand held to
a local repeater and I used 10 watts with a directional antenna to the
distant repeater with intervening land less than 100 foot elevation
variance. Contact was always assured.
Art


A couple of decades ago on 10 meters with a 3 element yagi and 100
watts, I frequently chatted with a grass valley station from a location
in calaveras county, a distance of over 75 miles as the crow flies (also
made a few contacts in San Francisco.) Antenna was 35 ft in the air and
the other guy in grass valley had a similar setup.

You never know, 'ya just never know ... but with two omni antennas, I
doubt it would have been done.

Now australia with an omni and a 100 watts? No problem with good sun spots!

JS

art wrote:

[...]

By the way, antennas never intimidated me much ...

The stacked 6 element hygain or mosley (modified CB antenna) on a 100
ft. tower with a ham m rotor was a real signal magnet and ionosphere
burner ... I still have that antenna leaning up against a shed in the
back 40 ...

Only real problem with that antenna was forgetting to face it into the
high winds in a storm and ripping the gears in the rotor.

Regards,
JS