Digital 2-way radios are gaining in popularity over their analog counterparts, but that does not always mean they are the best tool for the job at hand. Let’s explore the differences between the two, especially as they apply to racing applications.
We’ll begin with the technical mumbo-jumbo and if you’re uninterested feel free to jump down to the Feature Comparisons below.
How they work
Please note that this is a very simplified explanation of what actually happens when you transmit using a 2-way radio.
Both analog and digital radios send signals over a radio channel using a carrier frequency wave, in this case Very High Frequency (VHF) or Ultra High Frequency (UHF). However, the way the transmission is encoded over a channel frequency is different.
In simple terms, analog radios use frequency modulation (FM) to encode a voice signal within a carrier wave. Your voice changes, or modulates, the frequency of the wave. The difference between the modulated frequency and the baseline channel frequency can then be demodulated by the receiving radio and turned back into a comprehensible voice message.
Digital radios do the same thing, but they have an extra encoding step before the voice signal reaches the carrier wave. The voice message is encoded into binary packets (ones and zeroes). These packets of numbers are then able to modulate the frequency of the carrier wave. Notice that the modulated frequency of a digital signal is not a continuous wave but instead an intermittent stepped change.
Now that we have a very basic understanding of how analog and digital signals differ, lets jump into how this affects the user experience and race performance.
Feature Comparisons
Voice Quality
Digital radios far surpass analog radios when it comes to voice quality. Analog radios transmit every single noise that is picked up by the microphone allowing background noise to drown out the voice message. Digital reception however, can focus on the voice message and ignore all RF interference resulting in exceptional voice clarity. Additionally, digital radios are able to rebuild voice sounds using auto error correction if a signal is badly corrupted due to radio interference. However, since the digital radio converts your voice into binary numbers, it does make the voice sound a little bit robotic.
This video shows an actual audio recording of an analog vs digital transmission so you can hear the difference.
When it comes to racing, audio quality is extremely important because you don’t have time to repeat a garbled message. In recreational riding, where time isn’t usually as important, a static message becomes more of just an annoyance because you can always repeat the message if needed.
Coverage
While both an analog & digital 5-watt radio will transmit over the same distance, the digital radio will remain loud and clear all the way to the end of the covered area where as the analog radio will gradually fade and garble the further out they go.
The diagram below illustrates the difference.
This clarity makes digital radios great for short course racing but for longer desert races you are going to want to stick with analog.
Battery Life
In standby mode, both analog and digital radios consume about the same power, but once they start transmitting, digital radios are drastically more efficient. The constant wave transmission of an analog radio that we mentioned early is much more power hungry because it is constant whereas the intermittent packet transmission of a digital radio means it is only using power intermittently. This will make a digital radio battery last up to 40% longer.
Longer battery life is always a good thing but if your analog battery already lasts the duration of the race then battery life probably isn’t the best reason to upgrade to digital. If you are in the driver seat for 8 or more hours at a time, then the digital battery life will be to your benefit.
Channel Capacity
With analog radios, a single conversation takes up the entire channel bandwidth so if a channel is being used, you must then change to a new channel. When it comes to channel capacity and digital radios, it can get very technical very quickly. The important take-away is that digital radios are extremely efficient when it comes to channel bandwidth allowing you to double the capacity of a single channel. This means that many more people can communicate on a single channel without interference or worrying about privacy. Less radio traffic is always a good thing when you have an urgent message to transmit.
There are additional features and differences between analog and digital radios that we won’t cover in this post because they tend to not apply to racing applications. These include, data transmission such as text messaging, GPS location services, radio unit ID, and private call groups. A simple Google search can give you more information if needed.
Are Analog and Digital compatible?
No. An analog radio cannot transmit or receive a digital signal making the two types incompatible. However, many digital radios can be changed to analog mode making them able to transmit an analog signal . This allows you to slowly transition to digital without making all older analog radios obsolete.
Digital is the future of two-way radios but it will be awhile yet for the cost of a digital radio to rival the price of analog. Make sure you are taking into consideration your specific application when justifying the additional cost. There will always be those that prefer the antiquity of an analog radio over the new technology of a digital just as those who prefer a vinyl record over an MP3.