Digital vs Analog voice

[kayn1n32008]

Its Motorola in Taipei saying it is public safety grade. If it is good enough for the rest of the planet why not here?

Because tax dollars are buying it.

 

[bharvey2]

"Fire ground radio should go digital when the hydrants go digital!"

And that exemplifies the KISS principle but some are hell bent on trying to get around it.

 

[kd1sq]

Digital versus Analog...aaahhh!

For what it's worth, the digital mode on shortwave (DRM) gives great fidelity but requires far higher signal strengths to be reliably decoded. You'll find that an S2 signal on shortwave analog can still be picked out of the noise. On the other hand, you need about a S9+14 signal for reliable continuous decoding with DRM.

So, horses for courses - if the public coffer is full and you can put a LOT of repeater sites up, digital will work. If you're poor, analog is the way to go.

(Myself, cynic that I am, I think that digital systems are more about the equipment vendor profit than giving the customer the best bang for the buck.)

 

[romanr]

Digital versus Analog...aaahhh!

For what it's worth, the digital mode on shortwave (DRM) gives great fidelity but requires far higher signal strengths to be reliably decoded. You'll find that an S2 signal on shortwave analog can still be picked out of the noise. On the other hand, you need about a S9+14 signal for reliable continuous decoding with DRM.

So, horses for courses - if the public coffer is full and you can put a LOT of repeater sites up, digital will work. If you're poor, analog is the way to go.

(Myself, cynic that I am, I think that digital systems are more about the equipment vendor profit than giving the customer the best bang for the buck.)

Comparing DRM on HF ("shortwave") vs. DMR/P25 on VHF/UHF is difficult, if not futile. There are so many differences (bandwidth limited voice & data vs. High fidelity music, modulation, error coding & correction, etc.) that DRM vs DMR is not meaningful in this context, if any.

In the context of an Amateur Radio Forum, DMR & P25 hope to bring the benefits of reduced spectral usage and mixed voice/data communications. The LMR 'customer' for which these digital modes were developed were not concerned about hearing the violin 'E' string on classical music - they wanted intelligible voice communication coupled with the benefits of adding digital data transmission, and they had been forced into limited (12.5kHz) channel bandwidths.

So, in consideration of what the targeted 'customer' needed and wanted, the digital modes were/are delivering the best bang for the buck. That doesn't mean that certain vendors aren't trying to maximize the buck...but that's what business is supposed to do.

 

[JRayfield]

You can't compare DRM with DMR like you're attempting to do. Just because they're both digital doesn't mean that they 'act' the same at all.

In comparisons between DMR (specifically, MOTOTRBO) and analog, it's been found that, given the same antenna system, frequencies and transmitter power output levels, a DMR (specifically, MOTOTRBO) system will be +6 db over a narrow-band analog FM system and +3 db over a wide-band analog system. Simply put, a properly operating MOTOTRBO system will clearly outperform a properly operating analog system (especially a narrow-band analog FM system).

Simply put, digital offers comparable, or much better in many/most cases, performance as compared to analog FM systems.

John Rayfield, Jr.

Digital versus Analog...aaahhh!

For what it's worth, the digital mode on shortwave (DRM) gives great fidelity but requires far higher signal strengths to be reliably decoded. You'll find that an S2 signal on shortwave analog can still be picked out of the noise. On the other hand, you need about a S9+14 signal for reliable continuous decoding with DRM.

So, horses for courses - if the public coffer is full and you can put a LOT of repeater sites up, digital will work. If you're poor, analog is the way to go.

(Myself, cynic that I am, I think that digital systems are more about the equipment vendor profit than giving the customer the best bang for the buck.)

 

[romanr]

...much deleted...

Simply put, digital offers comparable, or much better in many/most cases, performance as compared to analog FM systems.

John Rayfield, Jr.

How many people compare Digital to Analog by driving away from the transmitting station until Digital drops, and then breaking squelch on an Analog channel to "see if they can make it out"? From this exercise, the anecdotes are born and forever more the belief is held that Analog gets better range. The problem is, no one drives around with their squelch broken (no one that is still sane, anyway...). In most cases, digital will still get through after the analog system will no longer break squelch, but few of these ad-hoc experiments are conducted in such a manner as to show this.

 

[mmckenna]

(Myself, cynic that I am, I think that digital systems are more about the equipment vendor profit than giving the customer the best bang for the buck.)

You may be a cynic, and that's OK.

However, on VHF/UHF, digital can sound better than analog. A lot of it has to do with the person who sets up the radio.

I run a couple of analog public safety repeaters and an NXDN trunked system.
I have a Kenwood NX-700 (analog/NXDN) radio in my work truck for VHF.
I have a Kenwood NX-900 (analog/NXDN) radio in that truck for 800MHz.
Same radios, different frequency. Same external speakers.

Our PSAP will dispatch on all of those system.
So, same dispatcher. Same microphone. Same radio console.
VHF analog is wireline to the Motorola Quantar repeaters running in analog mode, not P25.
800 is RF into the Kenwood NexEdge trunked system from fixed base radios connected to the console.

Comparing the audio from the same dispatcher, same mic to the same radio (yeah, different frequency) and same speakers, digital has better audio quality. More dynamic range in the audio, higher highs, lower lows when compared to analog.

To be fair, I did spend a lot of time tweaking audio on the digital radios. It's not a "slap a codeplug in and done" thing. Took some experimentation and consulting with Kenwood to make it sound good. Unfortunately not many take the time to set the radios up correctly before announcing that "digital sucks".

 

[KK6ZTE]

How many people compare Digital to Analog by driving away from the transmitting station until Digital drops, and then breaking squelch on an Analog channel to "see if they can make it out"? From this exercise, the anecdotes are born and forever more the belief is held that Analog gets better range. The problem is, no one drives around with their squelch broken (no one that is still sane, anyway...). In most cases, digital will still get through after the analog system will no longer break squelch, but few of these ad-hoc experiments are conducted in such a manner as to show this.

Additionally, managing to barely key a distant repeater is meaningless if there's not enough signal to effectively get audio out.

 

[rescue161]

How many people compare Digital to Analog by driving away from the transmitting station until Digital drops, and then breaking squelch on an Analog channel to "see if they can make it out"? From this exercise, the anecdotes are born and forever more the belief is held that Analog gets better range. The problem is, no one drives around with their squelch broken (no one that is still sane, anyway...). In most cases, digital will still get through after the analog system will no longer break squelch, but few of these ad-hoc experiments are conducted in such a manner as to show this.

I used to show folks on my repeaters the difference in coverage. I already posted this before, but I had 5 repeaters on one antenna (One TX and one RX through a combiner/multi-coupler). There were two analog wide-band UHF repeaters and three digital (two P25 Quantars and one XPR8400). I would prove every single time that digital would out perform analog and it would. I intentionally did not use the Quantars as they were 125 Watts, so I limited the test to the 40 Watt repeaters. Yes, you could walk around with the squelch hissing and holding the radio up in the air and you might have been able to pull the analog repeaters in, but the DMR repeater would be crystal clear.

 

[kb9mwr]

Skyler W0SKY did a pretty decent comparison here;