optimize signal for a Baofeng AR5RM

[Guest Tim]

I am a new radio user.  I purchased the Baofeng AR5RM hand radio.  I want to talk to my family that live within a 10 mile radius in the Kansas City, KS area.  I have a GMRS license.   Questions.

How do I optimze range, at this point it only goes about half kilometer?  Need at least 10 miles.

Do I need a repeater to boost signal?

I have Chirp installed on my computer.

[SteveShannon]

17 minutes ago, Guest Tim said:

I am a new radio user.  I purchased the Baofeng AR5RM hand radio.  I want to talk to my family that live within a 10 mile radius in the Kansas City, KS area.  I have a GMRS license.   Questions.

How do I optimze range, at this point it only goes about half kilometer?  Need at least 10 miles.

Do I need a repeater to boost signal?

I have Chirp installed on my computer.

A better antenna, mounted as high above your roof as possible (and the same on their end) might work. 

[dosw]

If you and your family member are both holding the radio at five feet off the ground, and there are absolutely no contours to the earth or other obstructions between you, you'll get about 5.5 miles range. This is because even lacking contours, at 5.5 miles the curvature of the earth will block your signal, if both antennas are at 5' off the ground.

 

If you can get both antennas 20 feet off the ground, the curvature of the earth will attenuate the signal at just under 11 miles. So, again, if there are no contours to the terrain, and there is nothing else between you, the curvature comes into play at just under 11 miles.

 

If you can get one antenna 30 feet off the ground, and the other is 5 feet (base station to handheld, for example), you will get 9.44 miles of range.

To get ten mile coverage with one handheld radio (antenna 5 feet) and the other radio a base station, the base station's antenna needs to be 36 feet off the ground.

 

Here's a formula you can use: range[miles] = 1.22459*sqrt(height[feet_antenna_A]) + 1.22459*sqrt(height[feet_antenna_B])

 

But that formula applies if the earth doesn't have any variations in the terrain. This is Kansas, but it's not *that* flat; there is some variation. That variation can help you or harm you. If you're able to take advantage of slight hills to get the antennas higher, great. If the slight hills block your antennas, not great.

As for a repeater, it doesn't change physics, it just adds a third antenna to the mix that, if placed in a location between you and your family members, or if placed high on a hillside that all of you can "see" at the same time, is able to be the antenna you talk through. Repeaters make a lot of sense where I live; there are mountains around me, and everyone lives in a valley below the mountains. So if someone has the ability to place a repeater 1000 or 1500 feet above the valley, everyone can access that repeater all over the valley. But you're in flatter terrain, and may not find such advantaged repeaters.

Also, this isn't a power issue. A 50w radio can't blast through the curvature of the earth. And if you all could "see" an antenna elevated a thousand feet over the area, you could all hit it at 2w from many miles away, until you reach the curvature limit again. A theoretical 1000 foot high antenna communicating with a handheld at 5 feet would have 41 miles range. The farthest repeater I can hit is 64 miles away, and I'm at 5000 feet elevation, the valley floor is 4200 feet, so we're both well above the obstructions around us and the curvature probably wouldn't eliminate our "line of sight" until we get to a distance of about 75 miles.

 

[WRDJ205]

3 minutes ago, dosw said:

if placed in a location between you and your family members, or if placed high on a hillside that all of you can "see" at the same time, is able to be the antenna you talk through.

As dosw said, the repeater would help you only if you could get it between the two locations.  And again, elevation is your friend.  10mi in flat-ish land is a lot to ask without some height.