Improving Small Walkie Talkie Range

On a recent camping weekend we decided to carry out 'scientific' tests on the range of some small 0.5 watt walkie talkies.

The tests would include:
1. Range test between 2 walkie talkies on flat ground with a clear line of sight.
2. Impact of holding one horizontal while the other is vertical.
3. Impact of height.
4. Will adding a 'rats tail' (wire connected to the negative battery connection) improve the range?
5. How about a strip of aluminum beer can?
6. Will a parabolic reflector improve range/clarity?
7. Range when communicating with a 5 watt walkie talkie?
8. Impact of terrain.

Supplies

0.5 Walkie Talkies

Beer Can

Wire

Distance From Camp

Having used these small 0.5 watt walkie talkies for a couple of years, I am a bit of a fan as they are cheap, normally good for a couple of hundred meters of clear communication and maybe up to 800 metres with some static.

Not bad for something that costs about $20 each and can be kept in your pocket.

Adding an Aluminum Rat Tail

A number of 'modifications' were tested to see if they could increase the range of these low power walkie talkies.

The first was to add a 'rat tail' or counterpoise to increase the arials effectiveness. As these Australian walkie talkies are in the 476 MH band the strip of aluminium cut from a beer can was measured to be a quarter of a wave lenght (17 cm).

Adding a Wire Rat Tail

In a similar way to the aluminium 'rats tail' or 'counterpoise', wire was added to another walkie talkie to see if it would effect the range.

Really, Adding a Beer Can?

A reflector made from a beer can would also be tested. While radio waves will past through some things like plaster board, they won't pass through metal. The idea is the radio waves which would normally go behind will be reflected forward with the aluminium reflector - increasing the strength of the signal. The reflector had been repurposed from a previously made candle reflector:

https://www.instructables.com/Beer-Can-Wi-Fi-Extender/

Let the Tests Begin

The small walkie talkies had fresh batteries fitted before attempting the tests

The tests would be quite simple; seperate 2 walkie talkies by 800 meters and check reception, keep increasing the distance untill reception was less clear and then test the impact of:

i) Having one held vertical and one horizontal.
ii) Aluminium rats tail.
iii) Wire rats tail.
iv) Adding a beer can reflector.

On the Beach for a Stroll

Testing the range was done on a beach.

Two of us walked 400 metres in opposite directions and then reception was tested.

To my surprise reception remained clear.

At 3 kms apart, one of the walkie talkies was held horizontal while the other remaind vertical. This resulted in a distant loss of reception and clarity. So keep both vertical for better reception.

Testing both the aluminium and wire counterpoise didn't appear to make a difference as reception remained clear until 4 kms apart when it became poorer. I walked up a 20 meter sand dune and reception became clear again. On coming back down to the beach, reception still remained clear. The beer can reflector was tried at one stage but got blown around a bit by the wind.

One of the walkie talkies lost connection during the tests. It was later found the channel had accidentally been changed. To prevent this from reoccurring, the 'lock' button was pressed.

After walking 2 kms in different directions (4kms total) on soft sand in the heat of the day it was suggested future testing could be done by driving to increase distances.

Around a Bay

The next morning another distance test was performed by driving from the camp and checking reception.

After 1.2 km reception became unclear, probably due to the terrain.

After continuing travelling around the bay, reception improved and at 3.3 km was crystal clear. The map shows the line of transmission would have been across the bay.

Connecting to a 5 Watt-er

Another test was done in a different direction, where there were some undulations and trees in the way, after 1 km reception became unclear, one of the walkie talkies was swapped to a 5 watt one (marked with a circle on the map) to resume communication. This continued to 2 km.

At 2.4 km reception was tested again. The 0.5 amp walkie talkie couldn't make connection with the 5 watt one. The wire rat tail was tried and broken up reception was achieved. Trying out the radio with the beer can reflector resulted in clearer communication.

Height Is Might

On the way home a final distance test was performed from a hill 50 meters high, over looking the 5 watt walkie talkie at the bay. The distance was 2.6 km and reception was made using just the walkie talkie, with a rat tail and using the beer can reflector. To my surprise another 3rd party joined our conversation and said from where they were (Shoal Bay), the test with the beer can reflector was clearer. I later checked and the conversation to Shoal Bay was 9.2 Km away, to a mobile radio.

Conclusion: To increase range have height and a clear path between walkie talkies.

Impact of Terrain

On a cycle trip a range test was done between a 5 watt walkie talkie (on a hill) and a 0.5 watt one that was 8 km cycling distance away. Communication was clear with a direct line distance of 6.5km. On viewing a terrain map, it can be seen there was a height difference of 40-50 meters between the 2 walkie talkies. This would have created a clear line of sight and explains the longer than expected distance achieved.

Field Testing the Reflector

It has previously been shown that a beverage can can be used as a reflector and might increase the range of a walkie talkie a bit.

I was keen to test this on the bike trip. And so deliberately tried to communicate just below the brow of a hill - where reception would be poor as signals can't go though hills. Reception was poor, but by putting on the make shift reflector, words could just be made out. The beer can reflector appeared to make a difference.

Takeaways

The biggest take away from using and testing 0.5 watt walkie talkies is that they are worthwhile. They are useful when kayaking or bike riding in a group. For example on the bike ride when a front rider missed a turn they were able to be contacted (via another walkie talkie user in the group) to let them know - they still weren't happy as they had just gone down a steep hill. If someone has a puncture the rest of the group can be be called for assistance. For riders at the back it is comforting to be able to communicate with front riders so the group remains together.

The 0.5 watt walkie talkies are about a tenth the cost of a 5 watt one, more compact and so more likely to be taken on a trip. On our bike touring trip the batteries lasted for more than 23 hrs of use and the AAA batteries can easily be replaced. The radios provide an excellent way to communicate when phone reception is not available and even if it is, are quicker and easier to use. If some others in the group have 5 watt walkie talkies all the better.

How far will they work for? This is determined by the terrain they are being used in. Having a direct line of sight will extend range and height can provide this. Keep both walkie talkies vertical. Oh, and will a beer can reflector improve reception? The tests done suggest it might.