| Ham and GMRS |
Type of
Operation
|
Environmental
Surroundings
|
Approx
Maximum
Distance
|
Brief
Explanation
|
Inside Car /
Inside Car |
Average |
< 1/2 mile
< 1 km |
Your car is a metal shield |
| Radio/Radio |
Metro Area |
1-3 mi
2-5 km |
Based on obstruction and
buildings |
| Radio/Radio |
Suburbs |
3-6 mi
5-10 km |
Based on the amount of
leaves on trees |
| Radio/Radio |
Flat Desert or
Over Water |
6-12 mi
10-20 km |
Based on line of sight to the
horizon |
| Radio/Radio |
Mountain to
Valley |
15-20 mi
25-30 km |
Based on height of
mountains and terrain below. |
| Radio/Radio |
Mountain to
Mountain |
30-35 mi
48-55 km |
Based on height of
mountains.
Possible, but definitely not typical. |
Radio via
Repeater |
Average |
30-75 mi
50-120 km |
Example: 15 miles to a
repeater, plus 20 miles to the other radio would
= 35 mi |
Ham Only |
Radio via
Repeater |
Connected to an Internet Wide Area
Network |
No Limit |
Distance determined by the
internet connection |
Radio/Radio
via Satellite |
Clear path to satellite |
> > > |
Distance determined by
altitude of the satellite. |
| Radio to ISS |
Clear path to International
Space Station |
> > > |
Distance determined by
altitude of the ISS. |
| |
|
|
|
Elevation and obstruction are the two key
factors in determining expected distance. A better antenna
will also increase the range of your radio, but
remember, there
is no 'Magic Antenna'.
|
Your elevation and lack of obstructions will determine the overall distance you
can achieve. Trees and buildings are not your friends when trying to reach
great distances.
This is where the repeater comes into play. A repeater is a two-way radio system
that listens to one frequency an rebroadcasts what it hears on another frequency
simultaneously. Where the terrain prevents direct communications, a repeater
greatly extends the overall coverage of your contact.
Now, let's take it one step farther. Let's connect the repeater to an
internet gateway. Now, using two similar systems connected via a gateway, these
systems can communicate any where the internet can go.
Are you ready for this? There are systems that allow licensed hams to connect
via the internet to these gateways using PCs, laptops and Smart Phones.
These systems require proof of proper licensing as the conversation will be
broadcast over the ham frequencies.
And let us not forget Satellite Communications. A whole different aspect of the
hobby.
The distance achieved is determined by the altitude of the satellite.
The sky is the limit.
The International Space Station.
The altitude varies between
330 km (205 mi) and 435 km (270 mi).
Direct contact with astronauts aboard and a VHF/UHF repeater.
All this with a 5W handheld.
BTW: When you see little 'Blister Pack' radios in the department store
advertised as 18/35 miles between two radios, they are talking Mountain to
Mountain or through a Repeater. There are No magic radios out there. Refer to
the chart above.
Enjoy your new toys.
John 'Miklor'
K3NXU
|
